Chapter 10 anglesic drugs

anaglesic nursing assessment

Adequate analgesia requires a holistic, comprehensive, and individualized patient assessment with specific attention to the type, intensity, and characteristics of the pain and the levels of comfort. Comfort, in this situation, is defined as the extent of physical and psychologic ease that an individual experiences. Perform a thorough health history, nursing assessment, and medication history as soon as possible or upon the first encounter with the patient, including questions about the following: (1) allergies to nonopioids, opioids, partial or mixed agonists, and/or opioid antagonists (see previous pharmacologic discussion for examples of specific drugs); (2) potential drug-drug and/or drug-food interactions; (3) presence of diseases or CNS depression; (4) history of the use of alcohol, street drugs, or any illegal drug or substance and/or history of substance abuse, with information about the substance, dose, and frequency of use; (5) results of laboratory tests ordered, such as levels of serum ALT, ALP, GGT, 5′-nucleotidase, and bilirubin (indicative of liver function), and/or levels of BUN and creatinine (reflective of renal function); abnormal liver or renal function may require that lower doses of analgesic be used to prevent toxicity or overdosage (see the Safety: Laboratory Values related to Drug Therapy box); (6) character and intensity of the pain, including onset, location, and quality (e.g., stabbing/knifelike, throbbing, dull ache, sharp, diffuse, localized, or referred); actual rating of the pain using a pain assessment scale (see later); and any precipitating, aggravating, and/or relieving factors; (7) duration of the pain (acute versus chronic); and (8) types of pharmacologic, nonpharmacologic, and/or adjunctive measures that have been implemented, with further explanation of the treatment's duration of use and overall effectiveness. To be thorough and effective, include in your assessment the factors or variables that may impact an individual's pain experience, such as physical factors (e.g., age, gender, pain threshold, overall state of health, disease processes, or pathologies) and emotional, spiritual, and cultural variables (e.g., reaction to pain, pain tolerance, fear, anxiety, stressors, sleep patterns, societal influences, family roles, phase of growth and development, and religious, racial, and/or ethnic beliefs or practices). Age-appropriate assessment tools are recommended in assessing pain across the lifespan (see later discussion). For pediatric and older adult patients, nonverbal behavior or cues and information from family members or caregivers may be helpful in identifying pain levels. In an older adult individual, physical and cognitive impairments may affect reporting of pain; however, this does not mean that the older adult patient is not experiencing pain—the patient's reporting may just be altered. Chronic pain and pain associated with cancer are both complex and multifactorial problems requiring a holistic approach with attention to other patient complaints, such as a decrease in activities of daily living, insomnia, depression, social withdrawal, anxiety, personality changes, and quality of life issues. Perform a system-focused nursing assessment with collection of both subjective and objective data as follows: neurologic status (e.g., level of orientation and alertness, level of sedation, sensory and motor abilities, reflexes); respiratory status (e.g., respiratory rate, rhythm, and depth; breath sounds); GI status (e.g., presence of bowel sounds; bowel patterns; complaints of constipation, diarrhea, nausea, vomiting, or abdominal discomfort); genitourinary status (e.g., urinary output; any burning or discomfort on urination; urinary retention); and cardiac status (e.g., pulse rate and rhythm, blood pressure, any problems with dizziness or syncope). Assess and document vital signs, including blood pressure, pulse rate, respirations, temperature, and level of pain (now considered the fifth vital sign). It is important to pull from one's knowledge base and remember that during the acute pain response, stimulation of the sympathetic nervous system may result in elevated values for vital signs, with an increase in blood pressure (120/80 mm Hg or higher), pulse rate (100 beats/min or higher), and respiratory rate and depth (20 breaths/min or higher and shallow breathing).

patient centered care opioid pediatric

Assessment of the pediatric patient is challenging, and all types of behavior that may indicate pain, such as muscular rigidity, restlessness, screaming, fear of moving, and withdrawn behavior, must be carefully considered. • Adequacy of pain management is more difficult to determine in children because of their inability to express themselves. Frequently the reason older pediatric patients do not verbalize their pain is their fear of treatment, such as injections. Compassionate and therapeutic communication skills, as well as the use of alternate routes of administration, as ordered, will help in these situations. • The "ouch scale" is often used to determine the level of pain in children. This scale is used to obtain the child's rating of the intensity of pain from 0 to 5 by means of simple face diagrams, from a very happy face for level 0 (no pain) to a sad, tearful face for level 5 (severe pain). Pain assessment is very important in pediatric patients because they are often undermedicated. Always thoroughly assess the pediatric patient's verbal and nonverbal behavior, and never underestimate the patient's complaints! Remember that parents and caregivers can play a very important role in this assessment. • The patient's baseline age, weight, and height are important to document, because drug calculations are often based on these variables. With the pediatric patient, check and double-check all mathematical calculations for accuracy to avoid excessive dosages; this is especially true for opioids. • Analgesics must be given, as ordered, before pain becomes severe, with oral dosage forms used first, if appropriate. • If suppositories are used, be careful to administer the exact dose and not to split, halve, or divide an adult dose into a child's dose. This may result in the administration of an unknown amount of medication and possible overdose. • When subcutaneous, intramuscular, and intravenous medications are used, the principle of atraumatic care in the delivery of nursing care must be followed. One technique used to help ensure atraumatic care is the application of a mixture of local anesthetics or other prescribed substances to the injection site before the injection is given. EMLA (lidocaine/prilocaine) is a topical cream that anesthetizes the site of the injection; if ordered, apply 1 to image hours before the injection. Consult policies and procedures for further instructions regarding its use. • Distraction and creative imagery may be used for older children such as toddlers or preschool-age children. • Always monitor pediatric patients very closely for any unusual behavior while receiving opioids. • Report the following signs and symptoms of central nervous system changes to the prescriber immediately if they occur: dizziness, lightheadedness, drowsiness, hallucinations, changes in level of consciousness, and sluggish pupil reaction. Do not administer further medication until the nurse receives further orders from the prescriber. • Always monitor and document vital signs before, during, and after the administration of opioid analgesics. An opioid medication is usually withheld if a patient's respirations are less than 12 breaths/min or if there are any changes in the level of consciousness. Always follow protocol, and never ignore a patient's status! • Generally speaking, smaller doses of opioids, with very close and frequent monitoring, are indicated for the pediatric patient. Giving oral medications with meals or snacks may help to decrease GI upset.

other opioid nursing interventions

For transdermal patches (e.g., transdermal fentanyl), two systems are used. The oldest type of patch contains a reservoir system consisting of four layers beginning with the adhesive layer and ending with the protective backing. Between these two layers are the permeable rate-controlling membrane and the reservoir layer, which holds the drug in a gel or liquid form. The newer type of patch has a matrix system consisting of two layers: one layer containing the active drug with the releasing and adhesive mechanisms, and the protective impermeable backing layer. The advantages of the matrix system over the reservoir system are that the patch is slimmer and smaller, it is more comfortable, it is worn for up to 7 days (the older reservoir system patch is worn for up to 3 to 4 days), and it appears to result in more constant serum drug levels. In addition, the matrix system is alcohol-free; the alcohol in the reservoir system often irritates the patient's skin. It is important to know what type of delivery system is being used so that proper guidelines are followed to enhance the system's and drug's effectiveness. Apply transdermal patches to only a clean, nonhairy area. When the patch is changed, place the new patch on a new site, but only after the old patch has been removed and the old site cleansed of any residual medication. Rotation of sites helps to decrease irritation and enhance drug effects. Transdermal patches require special discarding of old/used patches (see the Safety and Quality Improvement: Preventing Medication Errors box on p. 151). Transdermal systems are beneficial for the delivery of many types of medications, especially analgesics, and have the benefits of allowing multiday therapy with a single application, avoiding first-pass metabolism, improving patient compliance, and minimizing frequent dosing. However, the patient must be watched carefully for the development of any type of contact dermatitis caused by the patch (the prescriber is to be contacted immediately if this occurs) and maintain his or her own pain journal when at home. Journal entries are a valid source of information for the nurse, other health care professionals, the patient, and family members to assess the patient's pain control and to monitor the effectiveness not only of transdermal analgesia but also any medication regimen. With the intravenous administration of opioid agonists, follow manufacturer guidelines and health care institution policy regarding specific dilutional amounts and solutions as well as the time period for infusion. When PCA is used, the amounts and times of dosing must be noted in the appropriate records and tracked by appropriate personnel. The fact that a pump is being used, however, does not mean that it is 100% reliable or safe. Closely monitor and frequently check all equipment. Additionally, frequently monitor pain levels, response to medication, and vital signs with the use of other parenteral opioid administration. Always follow dosage ranges for all 165opioid agonists, and pay special attention to the dosages of morphine and morphine-like drugs. For intravenous infusions, you are responsible for monitoring the intravenous needle site and infusion rates and documenting any adverse effects or complications. Another point to remember when administering opioids—as well as any other analgesic—is that each medication has a different onset of action, peak, and duration of action, with the intravenous route producing the most rapid onset (e.g., within minutes) (Table 10-8).

non opioid anaglesic interventions

Give nonopioid analgesics as ordered or as indicated for fever or pain. Acetaminophen is to be taken as prescribed and within the recommended dosage range over a 24-hour period because of the risk for liver damage and acute toxicity. If a patient is taking other over-the-counter medications with acetaminophen, he or she needs to understand the importance of reading the labels very carefully (of other medications) to identify the total amount of acetaminophen taken and any other drug-drug interactions. In educating the patient, emphasize the signs and symptoms of acetaminophen overdose: bleeding, loss of energy, fever, sore throat, and easy bruising (due to hepatotoxicity). These must be reported immediately by the patient, family member, or caregiver to the nurse and/or prescriber. Any worsening or changing in the nature and/or characteristic of pain must also be reported. Suppository dosage forms of acetaminophen—like suppository forms of other drugs—may be placed into a medicine cup of ice to prevent melting of the dosage form. Once the suppository is unwrapped, cold water may be run over it to moisten the suppository for easier insertion. The suppository is inserted into the rectum using a gloved finger and water-soluble lubricating gel, if necessary. Acetaminophen tablets may be crushed if needed. Adult patients who take 3000 mg/day or greater of acetaminophen are at increased risk for acute hepatotoxicity. Death may occur after ingestion of more than 15 g. Liver damage from acetaminophen may be minimized by timely dosing with acetylcysteine (see previous discussion). If acetylcysteine is indicated, warn the patient about the drug's foul taste and odor. Many patients report that the drug smells and tastes like rotten eggs. Acetylcysteine is better tolerated if it is disguised by mixing with a drink such as cola or flavored water to increase its palatability. Use of a straw may help minimize contact with the mucous membranes of the mouth and is recommended. This antidote may be given through a nasogastric or orogastric tube or intravenously, if necessary. If a patient is receiving acetaminophen or taking it at home and has also been prescribed hydrocodone (Vicodin, Norco) or oxycodone (Percocet, Tylox), there is danger of overdosage with the acetaminophen. This overdosage may occur if the patient is not aware of the fact that acetaminophen is in the prescribed medication. Hepatotoxicity would be of concern, so it is critical to patient safety to educate about the ingredients of over-the-counter medications as well as prescribed medications. As discussed in the pharmacology section, the FDA announced that combination products are to be limited to 325 mg of acetaminophen, and they currently limit total daily doses to 4000 mg; however, the manufacturer of Tylenol suggests a limit 163of 3000 mg per day. Patients with liver disease or alcohol consumption are advised not to exceed 2000 mg per day. Tramadol may cause drowsiness, dizziness, headache, nausea, constipation, and respiratory depression. If dizziness, blurred vision, or drowsiness occur, be sure to assist the patient with ambulation (as with the use of any analgesic that may lead to dizziness or lightheadedness) to minimize the risk for fall and injury. Educate the patient about injury prevention, including the need to dangle the feet over the edge of the bed before full ambulation, changing positions slowly, and asking for assistance when ambulating. In addition, while the patient is taking tramadol—as well as any other analgesics, and especially opioids—the patient needs to avoid any tasks that require mental clarity and alertness. Increasing fluids and fiber in the diet may help with constipation. Use of flat cola, ginger ale, or dry crackers may help to minimize nausea.

potential drug interactions opioids

Potential drug interactions with opioids are significant. Co-administration of opioids with alcohol, antihistamines, barbiturates, benzodiazepines, phenothiazine, and other CNS depressants can result in additive respiratory depressant effects. The combined use of opioids, such as meperidine, with monoamine oxidase inhibitors, such as selegiline, can result in respiratory depression, seizures, and hypotension.

pca by proxy

most hospitals advice against

patient centered care and teaching of anaglesics

• Capsaicin is a topical product made from different types of peppers that may help with muscle pain and joint/nerve pain. It may cause local topical reactions, so be sure to share information with the patient about its safe use. • Opioids are not to be used with alcohol or with other CNS depressants, unless ordered, because of worsening of the depressant effects. Emphasize the importance of patients and caregivers knowing the ingredients of over-the-counter as well as prescribed medications. This is especially important if a patient is taking acetaminophen and also a combination opioid prescribed medication such as hydrocodone (Vicodin, Norco) or oxycodone (Percocet, Tylox) because of danger of overdosage with the acetaminophen (see previous discussions in this chapter). • A holistic approach to pain management may be appropriate, with the use of complementary modalities including the following: biofeedback, imagery, relaxation, deep breathing, humor, pet therapy, music therapy, massage, use of hot or cold compresses, and use of herbal products. • Dizziness, difficulty breathing, low blood pressure, excessive sleepiness (sedation), confusion, or loss of memory must be promptly reported to the nurse, prescriber, or other health care providers. • Opioids may result in constipation, so forcing fluids (up to 3 L/day unless contraindicated), increasing fiber consumption, and exercising as tolerated is recommended. Stool softeners may also be necessary. • Report any nausea or vomiting. Antiemetic drugs may be prescribed. • Any activities requiring mental clarity or alertness may need to be avoided if experiencing drowsiness or sedation. Ambulate with caution and/or assistance as needed. • It is important for the patient to share any history of addiction with health care providers, but when such a patient experiences pain and is in need of opioid analgesia, understand that the patient has a right to comfort. Any further issues with addiction may be managed during and after the use of opioids. Keeping an open mind regarding the use of resources, counseling, and other treatment options is important in dealing with addictive behaviors. • If pain is problematic and not managed by monotherapy, a combination of a variety of medications may be needed. Other drugs that may be used include antianxiety drugs, sedatives, hypnotics, or anticonvulsants. • For the cancer patient or patient with special needs, the prescriber will monitor pain control and the need for other options for therapy or for dosing of drugs. For example, the use of transdermal patches, buccal tablets, and continuous infusions while the patient remains mobile or at home is often helpful in pain management. It is also important to understand that if morphine or morphine-like drugs are being used, the potential for addiction exists; however, in specific situations, the concern for quality of life and pain management is more important than the concern for addiction. • Most hospitals have inpatient and outpatient resources such as pain clinics. Patients need to constantly be informed and aware of all treatment options and remain active participants in their care for as long as possible. • Tolerance does occur with opioid use, so if the level of pain increases while the patient remains on the prescribed dosage, the prescriber or health care provider must be contacted. Dosages must not be changed, increased, or doubled unless prescribed.

non opioid drug interactions

A few drugs interact with acetaminophen. Alcohol is potentially the most dangerous. Chronic heavy alcohol abusers may be at increased risk of liver toxicity from excessive acetaminophen use. For this reason, a maximum daily dose of 2000 mg is generally recommended for such patients. Health care professionals need to warn patients with regular intake of alcohol not to exceed recommended dosages of acetaminophen because of the risk for liver dysfunction and possible liver failure. Ideally, alcohol consumption is not to exceed three drinks daily. Other hepatotoxic drugs need to be avoided. Other drugs that potentially can interact with acetaminophen include phenytoin, barbiturates, warfarin, isoniazid, rifampin, beta blockers, and anticholinergic drugs, all of which are discussed in greater detail in later chapters.

nursing assessment pain assessment tools

A variety of pain assessment tools are available that may be used to gather information about the fifth vital sign. One very basic assessment tool is the Numeric Pain Intensity Scale (0 to 10 pain rating scale); patients are asked to rate their pain intensity by picking the number that most closely represents their level of pain. The Verbal Rating Scale, another pain assessment tool, uses verbal descriptors for pain, including words such as mild, moderate, severe, aching, agonizing, or discomfort. The FACES Pain Rating Scale is helpful in assessing pain in patients of all ages and educational levels because it relies on a series of faces ranging from happy to sad to sad with tears. The patient is asked to identify the face that best represents the pain he or she is experiencing at that moment. When the patient is in acute pain, when pain intensity is a primary focus for assessment, and/or when the need is to determine the efficacy of pain management intervention, the simple, one-dimensional scales (e.g., the Numeric Pain Intensity Scale) work best. The FLACC pain assessment scale may be used in children who are non-verbal but could also be used in any age of patient who is experiencing trauma or nonverbal. Zero, one, or two points are assigned to the five categories of Face, Legs, Activity, Cry, and Consolability. Further information is available at http://www.nhpco.org/flacc-scores. The older adult, especially those with cognitive impairment, may need more time to respond to the assessment tool and may also require large-print versions of written tools. There are other assessment tools that are multidimensional scales and are more beneficial in assessing patients who experience chronic rather than acute pain. One example is the Brief Pain Inventory assessment tool, which includes a body map so that the patient can identify on the figure the exact area where pain is felt. This tool also helps in obtaining information about the impact of pain on functioning. Assess pain before, during, and after the pain intervention, as well as the level of pain during activity and at rest. The following sections provide assessment information for specific drug classes.

naloxone hydrachloride

. _______________ is the drug of choice for the complete or partial reversal of opioid-induced respiratory depression

Methadone Hydrochloride (Dolophine)

Class: synthetic opioid Schedule: II INDICATIONS AND MOA: It is the opioid of choice for the detoxification treatment of opioid addicts in _______________ maintenance programs. There has been renewed interest in the use of _______________ for chronic (e.g., neuropathic) and cancer-related pain. The drug is readily absorbed through the GI tract with peak plasma concentrations at 4 hours for single dosing. _______________ is unique in that its half-life is longer than its duration of action because it is bound into the tissues of the liver, kidneys, and brain. With repeated doses, the drug accumulates in these tissues and is slowly released, thus allowing for 24-hour dosing. _______________ is eliminated through the liver, which makes it a safer choice than some other opioids for patients with renal impairment. Recent FDA reports have cited the prolonged half-life of the drug as a cause of unintentional overdoses and deaths Adverse effects: . Recent FDA reports have cited the prolonged half-life of the drug as a cause of unintentional overdoses and deaths. There is also concern that _______________ may cause cardiac dysrhythmias. Route: oral and injectable:

non opioid contraindications

Contraindications to acetaminophen use include known drug allergy, severe liver disease, and the genetic disease known as glucose-6-phosphate dehydrogenase (G6PD) deficiency.

opioid contraindications

Contraindications to the use of ¬¬¬¬¬¬¬¬¬¬¬¬______________analgesics include known drug allergy and severe asthma. It is not uncommon for patients to state they are allergic to codeine, when in the overwhelming majority of these patients nausea was the "allergic" reaction. Many patients will claim to be allergic to morphine because it causes itching. Itching is a pharmacologic effect due to histamine release and not an allergic reaction. Thus, it is important to determine the exact nature of a patient's stated allergy. Although not absolute contraindications, extreme caution is to be used in cases of respiratory insufficiency, especially when resuscitative equipment is not available and in conditions involving elevated intracranial pressure (e.g., severe head injury); morbid obesity and/or sleep apnea; myasthenia gravis; paralytic ileus (bowel paralysis); and pregnancy, especially with long-term use or high dosages.

Naloxone Hydrochloride (Narcan)

Class: pure opioid antagonist INDICATIONS AND MOA It has no agonistic morphine-like properties and works as a 157blocking drug for the opioid drugs. Accordingly, the drug does not produce analgesia or respiratory depression. _______________ is the drug of choice for the complete or partial reversal of opioid-induced respiratory depression. It is also indicated in cases of suspected acute opioid overdose. Failure of the drug to significantly reverse the effects of the presumed opioid overdose indicates that the condition may not be related to opioid overdose Primary adverse effects: opioid withdrawal syndraome Route : injectable Contraindication hypersensitivity

other nursing interventions opioids

When managing pain with morphine and similar drugs, withhold the dose and contact the prescriber if there is any decline in the patient's condition or if the vital signs are abnormal (see parameters mentioned earlier), especially if the 164respiratory rate is less than 10 breaths/min. Intramuscular injections are rarely used because of the availability of other effective and convenient dosage forms, such as PCA pumps, transdermal patches, continuous subcutaneous infusions, and epidural infusions.

Non-opioid analgesics

Acetaminophen (Tylenol) is the most widely used nonopioid analgesic. Acetaminophen is commonly abbreviated APAP in the United States; however, this abbreviation is not recognized in Canada. There is a current movement to stop using APAP as an abbreviation, because of the potential that patients will not realize they are receiving a prescription with acetaminophen and may take additional over-the-counter acetaminophen. All of the drugs in the NSAID class (which includes aspirin, ibuprofen, naproxen, the cyclooxygenase-2 [COX-2] inhibitor celecoxib [Celebrex], and others) are nonopioid analgesics. These drugs are discussed in greater detail in Chapter 44. They are used for management of pain, especially pain associated with inflammatory conditions such as arthritis, because they have significant antiinflammatory effects in addition to their analgesic effects. Miscellaneous analgesics include tramadol and transdermal lidocaine and are discussed in depth in their respective drug profiles in this chapter. Capsaicin is a topical product made from several different types of peppers. It works by decreasing or interfering with substance P, a pain signal in the brain. Capsaicin is available over the counter. It can be used for muscle pain, joint pain, and nerve pain. Milnacipran (Savella) is a selective serotonin and norepinephrine dual-uptake inhibitor. It is indicated for the treatment of fibromyalgia. It is thought that patients with fibromyalgia have reduced levels of norepinephrine in their brains, and milnacipran increases norepinephrine levels, which helps reduce pain associated with the disease.

non opioid adverse effects

Acetaminophen is generally well tolerated and is therefore available over the counter and in many combination prescription drugs. Possible adverse effects include skin disorders, nausea, and vomiting. Much less common but more severe are the adverse effects of blood disorders or dyscrasias (e.g., anemias) and nephrotoxicities, and hepatotoxicity. Hepatotoxicity is the most serious adverse effect of acetaminophen. Hepatotoxicity is associated with excessive doses. Acetaminophen is combined with hydrocodone (Vicodin, Norco) or oxycodone (Percocet, Tylox), and patients may exceed the recommended limit of acetaminophen without knowing these products also contain acetaminophen. In 2011, the FDA announced that combination products are to be limited to 325 mg of acetaminophen. 158Currently, the FDA limits total daily doses to 4000 mg; however, the manufacturer of Tylenol suggests a limit of 3000 mg per day. Patients with liver disease or chronic alcohol consumption are advised not to exceed 2000 mg per day

non opioid indications

Acetaminophen is indicated for the treatment of mild to moderate pain and fever. It is an appropriate substitute for aspirin because of its analgesic and antipyretic properties. Acetaminophen is also the antipyretic (antifever) drug of choice in children and adolescents with flu syndromes, because the use of aspirin in these populations is associated with a condition known as Reye's syndrome. It is also a valuable alternative for patients who cannot tolerate aspirin

adjuvant drugs

Adjuvant drugs are commonly used in the treatment of neuropathic pain, where opioids are not completely effective. Neuropathic pain usually results from nerve damage secondary to disease (e.g., diabetic neuropathy, postherpetic neuralgia secondary to shingles, AIDS or injury, including nerve damage secondary to surgical procedures [e.g., post-thoracotomy pain syndrome occurring after cardiothoracic surgery]). Common symptoms include hypersensitivity or hyperalgesia to mild stimuli such as light touch or a pinprick, or the bed sheets on a person's feet. This is also known as allodynia. It can also manifest as hyperalgesia to uncomfortable stimuli, such as pressure 149from an inflated blood pressure cuff on a patient's limb. It may be described as heat, cold, numbness and tingling, burning, or electrical sensations. Examples of adjuvants commonly used in these cases are the antidepressant amitriptyline and the anticonvulsants gabapentin and pregabalin.

Hydromorphone (Dilaudid)

Class : OPIOID Schedule :II INDICATIONS AND MOA: . It is approximately seven times more potent than morphine. It is most often referred to as Diludid, because _______________ can be mistaken for morphine. One milligram of IV or IM _______________ is equivalent to 7 mg of morphine. Many nurses are unfamiliar with the potency difference, and because it is given in low doses (0.2-1 mg) some inadvertently assume low dose means low potency. Many medication errors and deaths have occurred because of lack of knowledge of this potency difference. Exalgo is the osmotic extended release oral delivery system of _______________, which is difficult to crush or extract for injection, to help reduce the abuse potential. For dosage information, see the table on the previous page.

specifics of gate control theory of pain

Both the opening and the closing of this gate are influenced by the activation of large-diameter A fibers and small-diameter C fibers (Table 10-3). Closing of the gate is affected by the activation of A fibers. This causes the inhibition of impulse transmission to the brain and avoidance of pain sensation. Opening of the gate is affected by the stimulation of C fibers. This allows impulses to be transmitted to the brain and pain to be sensed. The gate is innervated by nerve fibers that originate in the brain and modulate the pain sensation by sending impulses to the gate in the spinal cord. These nerve fibers enable the brain to evaluate, identify, and localize the pain. Thus, the brain can control the gate, either keeping the gate closed or allowing it to open so that the brain is stimulated and pain is sensed. The cells that control the gate have a threshold. Impulses that reach these cells must rise above this threshold before an impulse is permitted to travel up to the brain.

tramadole

CLASS : NONOPIOID MISCELLANOUS _______________ hydrochloride (Ultram) is categorized as a miscellaneous analgesic due to its unique properties. It is a centrally acting analgesic with a dual mechanism of action. It creates a weak bond to the mu opioid receptors and inhibits the reuptake of both norepinephrine and serotonin. Although it does have weak opioid receptor activity, _______________ is not currently classified as a controlled substance. _______________ is indicated for the treatment of moderate to moderately severe pain. _______________ is rapidly absorbed, and its absorption is unaffected by food. It is metabolized in the liver to an active metabolite and eliminated via renal excretion. Adverse effects are similar to those of opioids and include drowsiness, dizziness, headache, nausea, constipation, and respiratory depression. Seizures have been reported in patients taking _______________ and can occur in patients taking both normal and excessive dosages. Patients who may be at greatest risk are those receiving tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors, neuroleptics, or other drugs that reduce the seizure threshold. There is also an increased risk for developing serotonin syndrome when _______________ is taken concurrently with SSRIs (see Chapter 16). In 2014, _______________ was rescheduled to a class CIV narcotic by the federal government, although certain states consider _______________ a CII or CIII drug. Use of _______________ is contraindicated in cases of known drug allergy, which may include allergy to opioids due to potential cross-reactivity. The drug is only available in oral dosage forms, including a combination with acetaminophen (Ultracet), as well as extended-release formulation (ConZip, Ryzolt, Ultram ER) and as an orally disintegrating tablet called Rybix. A new drug, tapentadol (Nucynta), is structurally related to _______________ with a dual mechanism of action. It is a mu agonist and a norepinephrine reuptake inhibitor. It is a Schedule II narcotic.

morphine

Class : opioid Shedule: II INDICATIONS indicated for severe pain and has a high abuse potential. ROUTE: available in oral, injectable, and rectal dosage forms. Extended-release forms include MS Contin and Kadian Adverse effects: also has a potentially toxic metabolite known as _______________-6-glucuronide. Accumulation of this metabolite is more likely to occur in patients with renal impairment. For this reason, other Schedule II opioids such as hydromorphone (Dilaudid), fentanyl, and oxymorphone (Opana) may be safer analgesic choices for patients with renal insufficiency. _______________ is available in oral, rectal, epidural, and injectable dosage forms, including PCA cartridges. Embeda (_______________ and naltrexone) is the newest _______________ product. For dosage information, see the table on p. 154.

Meperidine hydrochloride (Demerol)

Class : synthetic opioid Indications: migraine headache and postoperative reduced shivering CONTRAINDICATIONS: _______________ must be used with caution, if at all, in older adult patients and in patients who require long-term analgesia or who have kidney dysfunction. An active metabolite, nor_______________, can accumulate to toxic levels and lead to seizures. For this reason, _______________ is now used less commonly than before and is not recommended for long-term pain treatment. However, it is still used in emergency department settings for acute migraine headaches and in the immediate postoperative period to reduced shivering Route : oral and injectable

fentanyl

Class : synthetic opioid Schedule : II INDICATIONS AND MOA: used to treat moderate to severe pain. Like other opioids, it also has a high abuse potential. Route : parenteral injections, transdermal patches (Duragesic), buccal lozenges (Fentora), and buccal lozenges on a stick (Actiq). The buccal dosage forms are absorbed through the oral mucosa. The injectable form is used most commonly in perioperative settings and in intensive care unit settings for sedation during mechanical ventilation. _______________ is a very potent analgesic. _______________ in a dose of 0.1 mg intravenously is roughly equivalent to 10 mg of morphine intravenously Transdermal patch considerations The transdermal delivery system (patch) has been shown to be highly effective in the treatment of various chronic pain syndromes such as cancer-induced pain, especially in patients who cannot take oral medications. This route is not to be used in opioid-naïve patients or for acute pain relief. _______________ patches are difficult to titrate and are best used for nonescalating pain. _______________ patches take 6 to 12 hours to reach steady-state pain control after the first patch is applied, and supplemental short-acting therapy may be required. Most patients will experience adequate pain control for 72 hours with this method of _______________ delivery. A new patch is to be applied every 72 hours. It is important to remove the old patch when applying a new one. It takes about 17 hours for the amount of _______________ to reduce by 50% once the patch is removed. The U.S. Food and Drug Administration (FDA) has issued many safety warnings about the use of _______________ patches. _______________ patches are intended for management of chronic or cancer pain in opioid-tolerant patients whose pain is not adequately controlled by other types of medications. These patches are not to be used for acute pain situations such as postoperative pain. According to the FDA, patients who are considered opioid tolerant are those who have been taking at least 60 mg of oral morphine daily or at least 30 mg of oral oxycodone daily or at least 8 mg of oral hydromorphone daily or an equianalgesic dose of another opioid. Other hazards associated with the use of _______________ patches are cutting the patch and exposing the patch to heat (e.g., via a heating pad or sauna), both of which accelerate the diffusion of the drug into the patient's body. Unused patches should be flushed down the toilet. _______________ patches are often cut into pieces and sold on the street as "chicklets." Patients should be warned to keep all _______________ patches away from children, as deaths have occurred when toddlers inadvertently chewed _______________ patches.

Naltrexone hydrochloride

Class opioid antagonist INDICATIONS AND MOA: used as an adjunct for the maintenance of an opioid-free state in former opioid addicts. It is also indicated as an adjunct to psychosocial treatments of alcoholism and for reversal of postoperative opioid-induced respiratory depression. Adverse effects: Nausea and tachychardia Contraindications: drug allergy hepatitis and liver disfunction Route oral

Lidocaine (transdermal)

Class: NON opioid anglesic Transdermal _______________ is a topical anesthetic (see Chapter 11) that is formulated into a patch (Lidoderm) and is placed onto painful areas of the skin. It is indicated for the treatment of postherpetic neuralgia, a painful skin condition that remains 159after a skin outbreak of shingles. _______________ patches provide local pain relief, and up to three patches may be placed on a large painful area. The patches are not to be worn for longer than 12 hours a day to avoid potential systemic drug toxicity (e.g., cardiac dysrhythmias). Because they act topically, there are minimal systemic adverse effects. However, the skin at the site of treatment may develop redness or edema, and unusual skin sensations may occur. These reactions are usually mild and transient and resolve within a few minutes to hours. Patches are applied only to intact skin with no blisters. They can be used either alone or as part of adjunctive treatment with systemic therapies such as antidepressants (see Chapter 16), opioids, or anticonvulsants (see Chapter 14). Used patches must be disposed of securely because they may be dangerous to children or pets. Specific pharmacokinetic data are not listed due to the continuous nature of dosing. Studies have demonstrated that a patch can provide varying degrees of pain relief for 4 to 12 hours

acetaminophen

Class: Nonopioid analgesic INDICATIONS AND MOA used for mild to moderate pain relief. Contraindications; alcoholics and those who have hepatic disease Route: oral rectal and IV Other facts: also a component of several prescription combination drug products, including hydrocodone/_______________ (Vicodin) and oxycodone/_______________ (Percocet).

codeine sulfate

Class: OPIOID (natural opiate alkaloid) Schedule II INDICATIONS AND MOA : It is similar to morphine in terms of its pharmacokinetic and pharmacodynamic properties. In fact, about 10% of a _______________dose is metabolized to morphine in the body. However, _______________is less effective as an analgesic and is the only agonist to possess a ceiling effect (meaning increasing the dose will not increase response). It is more commonly used as an antitussive drug in an array of cough preparations (see Chapter 36). _______________combined with acetaminophen (tablets or elixir) is classified as a Schedule III controlled substance and is commonly used for control of mild to moderate pain as well as cough. When _______________is not combined with other drugs, it is classified as a Schedule II controlled substance, which implies a high abuse potential Adverse effects: GI tract upset, and many patients will say they are allergic to codeine, when in fact it just upsets their stomach. Other facts: not to be used with pediatric patients

oxycodone

Class: opioid Schedule II ROUTE and INDICATIONS: ). It is also commonly combined in tablets with acetaminophen (Percocet) and with aspirin (Percodan). _______________ is also available in immediate-release formulations (Oxy IR) and sustained-released formulations (OxyContin). A somewhat weaker but commonly used opioid is hydrocodone, which is available only in tablet form, most commonly in combination with acetaminophen (Vicodin, Norco). In 2014, hydrocodone was rescheduled as a CII drug. For dosage information, see the table on p. 154.

dosage form considerations

Dosage forms are also important, especially with chronic pain and cancer pain. Oral administration is always preferred but is not always tolerated by the patient and may not even be a viable option for pain control. If oral dosing is not appropriate, less invasive routes of administration include rectal and transdermal routes. Rectal dosage forms are safe, inexpensive, effective, and helpful if the patient is experiencing nausea or vomiting or altered mental status; however, this route is not suitable for those with diarrhea, stomatitis, and/or low white blood cell counts. Transdermal patches may provide up to 7 days of pain control but are not for rapid dose titration and are used only when stable analgesia has been previously achieved. Long-acting forms of morphine and fentanyl may be delivered via transdermal patches when a longer duration of action is needed. Intermittent injections or continuous infusions via the intravenous or subcutaneous route are often used for opioid delivery and may be administered at home in special pain situations, such as in hospice care or management of chronic cancer pain. Subcutaneous infusions are often used when there is no intravenous access. PCA pumps may be used to help deliver opioids intravenously, subcutaneously, or even intraspinally and can be managed in home health care or hospice care for the patient at home. Use of the intrathecal or epidural route requires special skill and expertise, and delivery of pain medications using these routes is available only from certain home health care agencies for at-home care. The main reason for long-term intraspinal opioid administration is intractable pain. Transnasal dosage forms are approved only for butorphanol, an agonist-antagonist drug, and this dosage form is generally not used or recommended. Regardless of the specific drug or dosage form used, a fast-acting rescue drug needs to be ordered and available for patients with cancer pain and patients presenting other special challenges in pain management.

breakthrough pain and adjuvants

For patients receiving long-acting opioids, breakthrough pain often occurs between doses of pain medications. This is because the analgesic effects wear off as the drug is metabolized and eliminated from the body. Treatment with "prn" (as needed) doses of immediate-release dosage forms (e.g., oxycodone IR) given between scheduled doses of extended-release dosage forms (e.g., oxycodone ER) is often helpful in these cases. Chewing or crushing of any extended-release opioid drug can 148cause oversedation, respiratory depression, and even death due to rapid drug absorption. If the patient is requiring larger doses for breakthrough pain, the dose of the scheduled extended-release opioid may need to be shortened or a more potent drug started. Drugs from other chemical categories are often added to the opioid regimen as adjuvant drugs. These assist the primary drugs in relieving pain. Such adjuvant drug therapy may include NSAIDs (see Chapter 44), antidepressants (see Chapter 16), antiepileptic drugs (see Chapter 14), and corticosteroids (see Chapter 33). This approach allows the use of smaller dosages of opioids and reduces some of the adverse effects that are seen with higher dosages of opioids, such as respiratory depression, constipation, and urinary retention. It permits drugs with different mechanisms of action to produce synergistic effects. Antiemetics (see Chapter 52) and laxatives (see Chapter 51) may also be needed to prevent or relieve associated constipation, nausea, and vomiting (Box 10-2). This multimodal approach has been shown to be very effective in treating pain.

non opioid pain assessment

For patients receiving nonopioid analgesics, focus the assessment not only on general data as described earlier but also on the specific drug being given. For example, in those patients taking acetaminophen, begin the assessment by determining whether the patient has allergies, is pregnant, and/or is breastfeeding. As mentioned in the pharmacology section, acetaminophen is contraindicated in those with severe liver disease and in patients with G6PD deficiency. Additionally, cautious use is necessary due to possible adverse effects of blood disorders (anemias) and liver or kidney toxicity. See the pharmacology discussion for more information about acute overdose and chronic unintentional misuse. Also assess for any other medications the patient is taking, because of the risk for excessive doses when taking combination products consisting of acetaminophen. Inadvertent overdosing is a possible consequence of this situation. Other drug interactions and concerns are addressed in the pharmacology discussion. Once therapy has been initiated, closely monitor for chronic acetaminophen poisoning, looking for symptoms such as rapid, 161weak pulse, dyspnea, and cold and clammy extremities. Long-term daily use of acetaminophen may lead to increased risk for permanent liver damage, and therefore you must frequently monitor the results of liver function studies. Adults who ingest higher than recommended dosages may be at higher risk for liver dysfunction as well as other adverse effects such as loss of appetite, jaundice, nausea, and vomiting. Children are also at high risk for liver dysfunction if the recommended dosage ranges are exceeded. With the use of NSAIDs (e.g., ibuprofen, aspirin, COX-2 inhibitors), assess kidney and liver functioning and gather information about GI disorders such as ulcers (see Chapter 44 for more information on antiinflammatory drugs). With aspirin, age is important; this drug is not to be given to children and adolescent patients because of the risk of Reye's syndrome. Aspirin may also lead to bleeding and ulcers, so ruling out conditions that represent contraindications and cautions to its use before therapy begins is important to patient safety. With tramadol hydrochloride, assessment of age is important because this drug is not recommended for use in individuals 75 years of age or older. A miscellaneous nonopioid analgesic, lidocaine transdermal, is another option for managing different types of pain. For lidocaine transdermal patches, understand that this transdermal drug is indicated in those with postherpetic neuralgia, and thus assess the herpetic lesion(s) and surrounding skin. When these patches are used, they must be kept away from children and are not to be prescribed for very young, small, or debilitated patients because these patients are at higher risk for toxicity. Liver function also needs to be assessed and monitored.

gi tract adverse effects of opioids and hypersensitivity

GI tract adverse effects are common in patients receiving opioids due to stimulation of GI opioid receptors. Nausea, vomiting, and constipation are the most common adverse effects. Opioids can irritate the GI tract, stimulating the chemoreceptor trigger zone in the CNS, which in turn may cause nausea and vomiting. Opioids slow peristalsis and increase absorption of water from intestinal contents. These two actions combine to produce constipation. This is more pronounced in hospitalized patients who are nonambulatory. Patients may require laxatives (see Chapter 51) to help maintain normal bowel movements. Urinary retention, or the inability to void, is another unwanted adverse effect of opioids, caused by increasing bladder tone. Severe hypersensitivity or anaphylactic reaction to opioid analgesics is rare. Many patients will experience GI discomforts or histamine-mediated reactions to opioids and call these "allergic reactions." However, true anaphylaxis is rare, even with intravenously administered opioids. Some patients may complain of flushing, itching, or wheal formation at the injection site, but this is usually local and histamine mediated, and not a true allergy. See Box 10-2 for additional information on opioid adverse effects and their managemen

nursing assessment opioid agonist-antagonist

In patients taking opioid agonists-antagonists, such as buprenorphine hydrochloride, assess vital signs with attention to respiratory rate and breath sounds. The opioid agonists-antagonists still possess opioid agonist effects; therefore, the assessment information related to opioids is applicable to these drugs as well. It is also very important to remember during assessment that these drugs are still effective analgesics and still have CNS depressant effects but are subject to a ceiling effect (see earlier definition). Given the action of these drugs, the assessment may help determine whether the patient is an abuser of opioids. This is important because the simultaneous administration of agonists-antagonists with another opioid will lead to reversal of analgesia and possible opioid withdrawal. Age is another factor to assess, because these drugs are not recommended for use in patients 18 years of age or younger. See the previous discussion for a listing of contraindications, cautions, and drug interactions.

PCA (patient controlled analgesia)

It is estimated that one of every three Americans experiences ongoing pain. Pain is poorly understood and often undertreated. Patient-controlled analgesia (PCA) is commonly used in the hospital setting. In this situation, patients are able to self-medicate by pressing a button on a PCA infusion pump. This has been shown to be very effective and reduces the total opioid dose used. Morphine and hydromorphone are commonly given by PCA. Potential hazards of PCA include well-meaning family members' pressing the dosing button rather than letting able patients do so on their own. Numerous deaths have occurred when well-meaning family members have administered too much of the opioid drug. This is called PCA by proxy. The Institute for Safe Medication Practices (ISMP) advises against PCA by proxy. For patients who are unable to self-medicate using the PCA pump, a different method of pain control must be used.

toxicity and managment of overdose non opioid

Many people do not realize that acetaminophen, despite its over-the-counter status, is a potentially lethal drug when taken in overdose. Depressed patients (especially adolescents) may intentionally overdose on the drug as an attention-seeking gesture without realizing the grave danger involved. The ingestion of large amounts of acetaminophen, as in acute overdose, or chronic unintentional misuse can cause hepatic necrosis. Acute ingestion of acetaminophen doses of 150 mg/kg (approximately 7 to 10 grams) or more may result in hepatotoxicity. Acute hepatotoxicity can usually be reversed with acetylcysteine, whereas long-term toxicity is more likely to be permanent. The long-term ingestion of large doses of acetaminophen is likely to result in severe hepatotoxicity, which may be irreversible. Because the reported quantity of drug ingested is often inaccurate, a serum acetaminophen concentration is determined no sooner than 4 hours after ingestion. If a serum acetaminophen level cannot be determined, it is assumed that the overdose is potentially toxic and treatment with acetylcysteine needs to be started. Acetylcysteine is the recommended antidote for acetaminophen toxicity and works by preventing the hepatotoxic metabolites of acetaminophen from forming. It is most effective when given within 10 hours of an overdose. Historically, the usual dosage regimen is a 140 mg/kg oral loading dose, followed by 70 mg/kg every 4 hours for 17 additional doses. This drug is notoriously bad tasting with an odor of rotten eggs, and vomiting of an oral dose is common. It is recommended that the dose be repeated if vomiting occurs within 1 hour of dosing. An intravenous dosage formulation of acetylcysteine (Acetadote) is also available and much better tolerated by the patient.

anglesic drugs

Medications that relieve pain without causing loss of consciousness are classified as analgesics. There are various classes of analgesics, determined by their chemical structures and mechanisms of action. This chapter focuses primarily on the opioid analgesics, which are used to manage moderate to severe pain. Often drugs from other chemical categories are added to the opioid regimen as adjuvant analgesic drugs (or adjuvants) and are described later. Pain is most commonly defined as an unpleasant sensory and emotional experience associated with either actual or potential tissue damage. It is a very personal and individual experience. Pain can be defined as whatever the patient says it is, and it exists whenever the patient says it does. Although the mechanisms of pain are becoming better understood, a patient's perception of pain is a complex process. Pain involves physical, psychologic, and even cultural factors (see the Patient-Centered Care: Cultural Implications box). Because pain intensity cannot be precisely quantified, health care providers must cultivate relationships of mutual trust with their patients to provide optimal care.

meperidine and normeperidine

Meperidine is not recommended for long-term use because of the accumulation of a neurotoxic metabolite, normeperidine, which can cause seizures. In 2010, the mild agonist propoxyphene (Darvocet) was withdrawn from the market due to adverse effects

opioid agonsit-antagonist intervention

Remember when giving agonists-antagonists that they react very differently depending on whether they are given by themselves or with other drugs. When administered alone, they are effective analgesics because they bind with opiate receptors and produce an agonist effect (see discussion in the pharmacology section). If given at the same time as other opioids, however, they lead to reversal of analgesia and acute withdrawal because of the blocking of opiate receptors. Be very careful to chieck dosages and routes as well as to perform the interventions mentioned for opioid agonist drugs, including closely assessing vital signs, especially respiratory rate. Emphasize the importance of reporting any dizziness, unresolved constipation, urinary retention, and sedation. See Table 10-6 for additional adverse effects of opioid agonists as they are similar to the opioid agonist-antagonist drugs. Other points to emphasize with the patient include that the drug also has the ability to reverse analgesia as well as precipitate withdrawal (if taken with other opioid agonists). A list of other opioid agonists must be shared with the patient, as well.

toxicity and managment of overdose of opioids

Naloxone and naltrexone are opioid antagonists, and they bind to and occupy all of the receptor sites (mu, kappa, delta). They are competitive antagonists with a strong affinity for these binding sites. Through such binding, they can reverse the adverse effects induced by the opioid drug, such as respiratory depression. These drugs are used in the management of both opioid overdose and opioid addiction and can also be used in small doses to treat itching associated with opioid use. The commonly used opioid antagonists (reversal drugs) are listed in Table 10-7. Some degree of physical dependence is expected in opioid-tolerant patients. The extent of opioid tolerance is most visible when an opioid drug is discontinued abruptly or when an opioid antagonist is administered. This usually leads to symptoms of opioid withdrawal, also known as abstinence syndrome (see Chapter 17). This can occur after as little as 2 weeks of opioid therapy in opioid-naïve patients. Gradual dosage reduction after chronic opioid use, when possible, helps to minimize the risk and severity of withdrawal symptoms. 153 Respiratory depression is the most serious adverse effect associated with opioids. Stimulating the patient may be adequate to reverse mild hypoventilation. If this is unsuccessful, ventilatory assistance using a bag and mask or endotracheal intubation may be needed to support respiration. Administration of opioid antagonists (e.g., naloxone) may also be necessary to reverse severe respiratory depression. Careful titration of dose until the patient begins to breathe independently will prevent over-reversal. The effects of naloxone are short-lived and usually last about 1 hour. With long-acting opioids, respiratory depressant effects may reappear, and naloxone may need to be re-dosed. The onset of withdrawal symptoms is directly related to the half-life of the opioid analgesic being used. Withdrawal symptoms resulting from the discontinuance or reversal of therapy with short-acting opioids (codeine, hydrocodone, morphine, and hydromorphone) will appear within 6 to 12 hours and peak at 24 to 72 hours. Withdrawal symptoms associated with the long half-life drugs (methadone, levorphanol, and transdermal fentanyl) may not appear for 24 hours or longer after drug discontinuation and may be milder.

nursing intervention anaglesics

Once the cause of pain has been diagnosed or other assessment and data gathering have been completed, begin pain management immediately and aggressively in conformity with the needs of each individual patient and situation. Pain management is varied and multifaceted and needs to incorporate pharmacologic as well as nonpharmacologic approaches (see Box 10-1 and the Safety: Herbal Therapies and Dietary Supplements box). Pain management strategies must also include consideration of the type of pain and pain rating as well as pain quality, duration, and precipitating factors, and interventions that help the pain. Some general principles of pain management are as follows: (1) Individualize a plan of care based on the patient as a holistic and cultural being (see the Patient-Centered Care: Cultural Implications box on p. 144). (2) Manage mild pain with the use of nonopioid drugs such as acetaminophen, tramadol, and NSAIDs (see Chapter 44). (3) Manage moderate to severe pain with a stepped approach using opioids. Other analgesics or types of analgesics may be used in addition to other categories of medication (see pharmacology discussion). (4) Administer analgesics as ordered but before the pain gets out of control. (5) Always consider the use of nonpharmacologic comfort measures (see Box 10-1) such as ice, heat, elevation, rest, homeopathic and folk remedies, exercise, distraction, music or pet therapy, massage, and transcutaneous electrical stimulation. Although not always effective, these measures may prove beneficial for some patients. See Patient-Centered Care: Patient Teaching on p. 168 for more information related to analgesics.

chemical structure of opioids

Opioid analgesics are very strong pain relievers. They can be classified according to their chemical structure or their action at specific receptors. Of the 20 different natural alkaloids available from the opium poppy plant, only three are clinically useful: morphine, codeine, and papaverine. Of these, only morphine and codeine are pain relievers; papaverine is a smooth muscle relaxant. Relatively simple synthetic chemical modifications of these opium alkaloids have produced the three different chemical classes of opioids: morphine-like drugs, meperidine-like drugs, and methadone-like drugs (Table 10-4). Knowing the chemical structure of the different opioids can be important in determining the appropriate drug for patients who are 150experience significant allergic reactions to a specific opioid. For example, if a patient experiences anaphylaxis from morphine, giving a drug with an unrelated structure such as fentanyl would be appropriate.

OPIOIDS MOA AND EFFECTS

Opioid analgesics can also be characterized according to their mechanism of action. They are agonists, agonists-antagonists, or antagonists (nonanalgesic). An agonist binds to an opioid pain receptor in the brain and causes an analgesic response—the reduction of pain sensation. An agonist-antagonist, also called a partial agonist or a mixed agonist, binds to a pain receptor and causes a weaker pain response than does a full agonist. Different drugs in this class exert their agonist and/or antagonist effects by binding in different degrees to kappa and mu opioid receptors. Although not normally used as first-line analgesics, they are sometimes useful in pain management in obstetrical patients (because they avoid oversedation of the mother and/or fetus). An antagonist binds to a pain receptor but does not reduce pain signals. It functions as a competitive antagonist because it competes with and reverses the effects of agonist and agonist-antagonist drugs at the receptor sites. The receptors to which opioids bind to relieve pain are listed in Table 10-5. The mu, kappa, and delta receptors are most responsive to drug activity, with the mu being the most important. Many of the characteristics of a particular opioid, such as its ability to sedate, its potency, and its ability to cause hallucinations, can be attributed to relative affinity for these various receptors. Understanding the relative potencies of various drugs becomes important in clinical settings. Equianalgesia refers to the ability to provide equivalent pain relief by calculating dosages of different drugs and/or routes of administration that provide comparable analgesia. Box 10-3 lists equianalgesic doses for several common opioids and shows how to calculate dosage conversions for patients. For example, hydromorphone (Dilaudid) is seven times more potent than morphine. Deaths have been reported where a nurse gave the patient morphine and, not realizing the equialanagesic equivalency, gave the same patient hydromorphone a short time later. It is critical to understand that hydromorphone is seven times more potent than morphine.

opioid antagonist intervention

Opioid antagonists must be given as ordered and be readily available, especially when the patient is receiving PCA with an opioid, is opioid naïve, or is receiving continuous doses of opioids. Several doses of these drugs are often required to ensure adequate opioid agonist reversal (see earlier discussion). Encourage patients to report any nausea or tachycardia.

lab test results of opioids

Opioids can cause an abnormal increase in the serum levels of amylase, alanine aminotransferase, alkaline phosphatase, bilirubin, lipase, creatinine kinase, and lactate dehydrogenase (see the Safety: Laboratory Values Related to Drug Therapy box). Other abnormal results include a decrease in urinary 17-ketosteroid levels and an increase in the urinary alkaloid and glucose concentrations.

opioids adverse effects part 1

Opioids that have an affinity for mu receptors and have rapid onset of action produce marked euphoria, and are most likely to be abused. All opioid drugs have a strong abuse potential. They are common recreational drugs of abuse among the lay public and also among health care professionals, who often have relatively easy access. The person taking them to alter his or her mental status will soon become psychologically dependent (addicted; see Chapter 17). In addition, opioids cause histamine release. It is thought that this histamine release is responsible for many of the drugs' unwanted adverse effects, such as itching or pruritus, rash, and hemodynamic changes. Histamine release causes peripheral arteries and veins to dilate, which leads to flushing and orthostatic hypotension. The amount of histamine release that an opioid analgesic causes is related to its chemical class. The naturally occurring opiates (e.g., morphine) elicit the most histamine release; the synthetic opioids (e.g., meperidine) elicit the least histamine release. (See Table 10-4 for a list of the various opioids and their respective chemical classes.)

Opioid agonist-antagonist

Opioids with mixed actions are often called agonists-antagonists (Schedule IV). They bind to the mu receptor and compete with other substances for these sites. They either exert no action (i.e., they are competitive antagonists) or have only limited action (i.e., they are partial agonists). They are similar to the opioid agonists in terms of their therapeutic indications; however, they have a lower risk for misuse and addiction. The antagonistic activity of this group can produce withdrawal symptoms in opioid-dependent patients. Their use is contraindicated in patients who have shown hypersensitivity reactions to the drugs. These drugs have varying degrees of agonist and antagonist effects on the different opioid receptor subtypes. They are used in situations requiring short-term pain control, such as after obstetric procedures. They are sometimes chosen for patients who have a history of opioid addiction. These medications can both help prevent overmedication and reduce posttreatment addictive cravings in these patients. Combination products of buprenorphine and naloxone offer physicians an in-office treatment of addiction (see Chapter 17). These drugs are normally not strong enough for management of longer-term chronic pain (e.g., cancer pain, chronic lower back pain). They are not to be given concurrently with full opioid agonists, because they may both reduce analgesic effects and cause withdrawal symptoms in opioid-tolerant patients. Adverse reactions are similar to opioids but with a lower incidence of respiratory depression. Four opioid agonists-antagonists are currently available: buprenorphine (Buprenex), butorphanol (Stadol), nalbuphine (Nubain), and pentazocine (Talwin). They are available in various oral, injectable, and intranasal dosage forms. A new transdermal form of buprenorphine (Butrans) is also available

categories of pain

Pain can be further classified according to its source. The two most common sources of pain are somatic and visceral. Somatic pain146 originates from skeletal muscles, ligaments, and joints. Visceral pain originates from organs and smooth muscles. Superficial pain originates from the skin and mucous membranes. Deep pain occurs in tissues below skin level. Pain may be appropriately treated when the source of the pain is known. For example, visceral and superficial pain usually require opioids for relief, whereas somatic pain (including bone pain) usually responds better to nonopioid analgesics such as nonsteroidal antiinflammatory drugs (NSAIDs) (see Chapter 44). Pain may be further subclassified according to the diseases or other conditions that cause it. Vascular pain is believed to originate from the vascular or perivascular tissues and is thought to account for a large percentage of migraine headaches. Referred pain occurs when visceral nerve fibers synapse at a level in the spinal cord close to fibers that supply specific subcutaneous tissues in the body. An example is the pain associated with cholecystitis, which is often referred to the back and scapular areas. Neuropathic pain usually results from damage to peripheral or CNS nerve fibers by disease or injury but may also be idiopathic (unexplained). Phantom pain occurs in the area of a body part that has been removed—surgically or traumatically—and is often described as burning, itching, tingling, or stabbing. It can also occur in paralyzed limbs following spinal cord injury. Cancer pain can be acute or chronic or both. It most often results from pressure of the tumor mass against nerves, organs, or tissues. Other causes of cancer pain include hypoxia from blockage of blood supply to an organ, metastases, pathologic fractures, muscle spasms, and adverse effects of radiation, surgery, and chemotherapy. Central pain occurs with tumors, trauma, inflammation, or disease (e.g., cancer, diabetes, stroke, multiple sclerosis) affecting CNS tissues.

pain medication and tolerance

Patients with complex pain syndromes often benefit from a holistic or multimodal clinical approach that involves pharmacologic and/or nonpharmacologic treatment. Effective drug therapy may include use of opioid and/or nonopioid drugs. The main consideration in pain management for pain associated with cancer is patient comfort and not trying to prevent drug addiction (or psychologic dependence; see Chapter 17). Opioid tolerance is a state of adaptation in which exposure to a drug causes changes in drug receptors that result in reduced drug effects over time. This can occur in as little as 1 week. Because of increasing pathology (e.g., tumor burden), cancer patients usually require increasingly higher opioid doses and thus do become physically dependent on the drugs. Cancer patients are likely to experience withdrawal symptoms (see Chapter 17) if opioid doses are abruptly reduced or discontinued; however, actual psychologic dependence or addiction in such patients is unusual. For long-term pain control, oral, intravenous, subcutaneous, transdermal, and rectal dosing routes are favored over multiple intramuscular injections.

evaluation of anaglesics

Positive therapeutic outcomes of acetaminophen use are decreased symptoms, fever, and pain. Monitor for the adverse reactions of anemias and liver problems due to hepatotoxicity, and report patient complaints of abdominal pain and/or vomiting to the prescriber. During and after the administration of nonopioid analgesics, such as tramadol, as well as opioids and mixed opioid agonists, monitor the patient for both therapeutic effects and adverse effects frequently and as needed. Therapeutic effects of analgesics include increased comfort levels as well as decreased complaints of pain and longer periods of comfort, with improvements in performance of activities of daily living, appetite, and sense of well-being. Monitoring for adverse effects will vary with each drug (see earlier discussions), but effects may consist of nausea, vomiting, constipation, dizziness, headache, blurred vision, decreased urinary output, drowsiness, lethargy, sedation, palpitations, bradycardia, bradypnea, dyspnea, and hypotension. If the patient's vital signs change, the patient's condition declines, or pain continues, contact the prescriber immediately and continue to closely monitor the patient. Respiratory depression may be manifested by a respiratory rate of less than 10 breaths/min, dyspnea, diminished breath sounds, and/or shallow breathing. Include a review of the effectiveness of multimodal and nonpharmacologic approaches to pain management in your evaluation.

considerations for anaglesics

Regardless of the drug(s) used for the pain management regimen, always remember that individualization of treatment is one of the most important considerations for effective and quality pain control. Also consider implementing the following: • At the initiation of pain therapy, conduct a review of all relevant histories, laboratory test values, nurse-related charting entries, and diagnostic study results in the patient's medical record. If there are underlying problems, consider these variables while never forgetting to treat the patient with dignity and empathy. Never let compounding variables 167and any other problems overshadow the fact that there is a patient who is in pain and deserving of safe, quality care. Always look and listen! • Develop goals for pain management in conjunction with the patient, family members, significant others, and/or caregiver. These goals include improving the level of comfort with increased levels of activities of daily living and ambulation. • Collaborate with other members of the health care team to select a regimen that will be easy for the patient to follow while in the hospital and, if necessary, at home (e.g., for cancer patients and other patients with chronic pain). • Be aware that most regimens for acute pain management include treatment with short-acting opioids plus the addition of other medications such as NSAIDs. • Be familiar with equianalgesic doses of opioids, because lack of knowledge may lead to inadequate analgesia or overdose. • Use an analgesic appropriate for the situation (e.g., short-acting opioids for severe pain secondary to a myocardial infarction, surgery, or kidney stones). For cancer pain, the regimen usually begins with short-acting opioids with eventual conversion to sustained-release formulations. • Use preventative measures to manage adverse effects. In addition, a switch is made to another opioid as soon as possible if the patient finds that the medication is not controlling the pain adequately. • Consider the option of analgesic adjuvants, especially in cases of chronic pain or cancer pain; these might include other prescribed drugs such as NSAIDs, acetaminophen, corticosteroids, anticonvulsants, tricyclic antidepressants, neuroleptics, local anesthetics, hydroxyzine, and/or psychostimulants. Over-the-counter drugs and herbals may be helpful. • Be alert to patients with special needs, such as patients with breakthrough pain. Generally, the drug used to manage such pain is a short-acting form of the longer-acting opioid being given (e.g., immediate-release morphine for breakthrough pain while sustained-release morphine is also used). • Identify community resources that can assist the patient, family members, and/or significant others. These resources may include various websites for patient education such as www.theacpa.org, www.painconnection.org, and www.painaction.com. Many other pain management sites may be found on the Internet by using the search terms pain, pain clinic, or pain education and looking for patient-focused materials/sites. • Conduct frequent online searches to remain current on the topic of pain management, pain education, drug and non-drug therapeutic regimens for pain, and special pain situations. The following professional nurse and/or prescriber-focused websites are listed at www.painedu.org/resources.asp as resources for the topic of general pain management: www.aapainmanage.org,www.painmed.org,www.painfoundation.org,www.ampainsoc.org,www.aspmn.org,www.asam.org,www.paineducators.org,www.asra.com,www.iasp-pain.org,www.painpolicy.wisc.edu,www.painmedicinenews.com,www.pain-topics.org,www.pain.com, and www.painandhealth.org. On the topic of chronic pain, websites are as follows: www.theacpa.org and www.arthritis.org. On the topic of cancer pain, websites are as follows: www.cancer.org,www.apos-society.org, www.asco.org, www.cancercare.org, www.cancer.gov, and www.ons.org. • Because fall prevention is of utmost importance in patient care (after the ABCs [airway, breathing, circulation] of care are addressed), monitor the patient frequently after an analgesic is given. Frequent measurement of vital signs, inclusion of the patient in a frequent watch program, and/or use of bed alarms is encouraged. • Restraints may cause many injuries; therefore, if restraints are necessary, follow the appropriate policies and procedures. Assess, monitor, evaluate, and document the reason for the restraint; also document the patient's behavior, the type of restraint used, and the assessment of the patient after the placement of restraints. Use of restraints has been largely replaced with a bed watch system and the use of bed and/or wheelchair alarms. Give instructions to the patient, family members, and/or caregivers about the risk for falls and the need for safety measures. Restraints are not used in long-term health care settings.

nursing assessment opioid antagonsit

Remember that the opioid antagonists are used mainly in reversing respiratory depression secondary to opioid overdosage. Naloxone may be used in patients of all ages, including neonates and children. Assess and document vital signs before, during, and after the use of the antagonist so that the therapeutic effects can be further assessed and documented and the need for further doses determined. In addition, remember that the antagonist drug may not work with just one dosing and that repeated doses are generally needed to reverse the effects of the opioid. See the pharmacology section for information about contraindications, cautions, and drug interactions.

gate control theory of pain

Several theories attempt to explain pain transmission and pain relief. The most common and well described is the gate theory. This theory, proposed by Melzack and Wall in 1965, uses the analogy of a gate to describe how impulses from damaged tissues are sensed in the brain. First, the tissue injury causes the release of several substances from injured cells, such as bradykinin, histamine, potassium, prostaglandins, and serotonin. Some current pain medications work by altering the actions and levels of these substances (e.g., NSAIDs → prostaglandins; antidepressants → serotonin). The release of these pain-mediating chemicals initiates action potentials (electrical nerve impulses) at the distal end of sensory nerve fibers through pain receptors known as nociceptors. These nerve impulses are conducted along sensory nerve fibers and activate pain receptors in the dorsal horn of the spinal cord. It is here that the so-called gates are located. These gates regulate the flow of sensory nerve impulses. If impulses are stopped by a gate at this junction, no impulses are transmitted to the higher centers of the brain. Conversely, if the gates permit a sufficient number and intensity of action potentials to be conducted from the spinal cord to the cerebral cortex, the sensation of pain is then felt. This is known as nociception. Figure 10-2 depicts the gate theory of pain transmission.

other indications of opioids

Strong opioids such as morphine, hydromorphone, and oxycodone are often used to control postoperative and other types of pain. Because morphine and hydromorphone are available in injectable forms, they are often first-line analgesics in the immediate postoperative setting. There is a trend away from using meperidine due to its greater risk for toxicity (see Drug Profile). All available oxycodone dosage forms are orally administered. The product OxyContin is a sustained-release form of oxycodone that is designed to last up to 12 hours. The "Contin" in the product name is a trademark of the original drug manufacturer, and refers to the "continuous-release" nature of the drug formulation. Recall that a continuous- or extended-release dosage form of a drug means that it has a prolonged duration of action, most often 8 to 24 hours (see Chapter 2). Similarly, the drug product MS Contin is a long-acting or sustained-release form of morphine. The "MS" stands for morphine sulfate. Both drugs are also available generically. In 2013, the FDA approved a risk evaluation and mitigation strategy (REMS) for long-acting opioids. The FDA requires prescriber and patient education to help combat prescription opioid misuse and deaths. There are also immediate-release dosage forms of oxycodone and morphine in tablet, capsule, and liquid form. The analgesic effects of immediate-release oral dosage forms of all three drugs typically last for about 4 hours. Opioids also suppress the medullary cough center, which results in cough suppression. The most commonly used opioid for this purpose is codeine (see Chapter 36). Hydrocodone is also used in many cough suppressants, either alone or in combination with other drugs. Constipation is often an unwanted side effect of opioids due to decreased gastrointestinal (GI) tract motility. It occurs because opioid drugs bind to intestinal opioid receptors. However, this effect is sometimes helpful in treating diarrhea. Some of the opioid-containing antidiarrheal preparations are camphorated opium tincture (paregoric) and diphenoxylate/atropine (Lomotil) tablets.

label of addict

The label of "addict" can be used unfairly to justify refusal to prescribe pain medications, resulting in undertreatment of pain, even in patients who do not use street drugs. This is now regarded as an inappropriate and inhumane clinical practice. In these situations, control of the patient's pain takes ethical and clinical priority over concerns regarding drug addiction. Nonetheless, prescribers must contend with the reality of abuse of street and/or prescription drugs by patients without genuine pain conditions (see Chapter 17). Such patients often request excessive numbers of prescriptions and may use multiple prescribers and/or pharmacies.

patient comfort and not trying to prevent drug addiction

The main consideration in pain management for pain associated with cancer is

indications of opioids

The main use of opioids is to alleviate moderate to severe pain. The amount of pain control or unwanted adverse effects depends on the specific drug, the receptors to which it binds, and its chemical structure. Strong opioid analgesics such as fentanyl, sufentanil, and alfentanil are commonly used in combination with anesthetics during surgery. Use of fentanyl injection for management of postoperative and procedural pain has become popular due to its rapid onset and short duration. Transdermal fentanyl comes in a patch formulation for use in long-term pain management and is not to be used for postoperative or any other short-term pain control (see the Safety and Quality Improvement: Preventing Medication Errors box)

non opioid MOA

The mechanism of action of acetaminophen is similar to that of the salicylates. It blocks peripheral pain impulses by inhibition of prostaglandin synthesis. Acetaminophen also lowers febrile body temperatures by acting on the hypothalamus, the structure in the brain that regulates body temperature. Heat is dissipated through vasodilation and increased peripheral blood flow. In contrast to NSAIDs, acetaminophen lacks antiinflammatory effects. Although acetaminophen shares the analgesic and antipyretic effects of the salicylates and other NSAIDs, it does not have many of the unwanted effects of these drugs. For example, acetaminophen products are not usually associated with cardiovascular effects (e.g., edema) or platelet effects (e.g., bleeding), as are aspirin and other NSAIDs. It also does not cause the aspirin-related GI tract irritation or bleeding, nor any of the aspirin-related acid-base changes.

adverse effects of opioids part 2 (CNS/Respiratory depression)

The most serious adverse effect of opioid use is CNS depression, which may lead to respiratory depression. When death occurs from opioid overdose, it is almost always due to respiratory depression. When opioids are given, care must be taken to titrate the dose so that the patient's pain is controlled without affecting respiratory function. Individual responses to opioids vary, and patients may occasionally experience respiratory compromise despite careful dose titration. Respiratory depression can be prevented in part by using drugs with very short duration of action and no active metabolites. Respiratory depression seems to be more common in patients with a preexisting condition causing respiratory compromise, such as asthma, chronic obstructive pulmonary disease, or sleep apnea. Respiratory depression is strongly related to the degree of sedation (see Toxicity and Management of Overdose later in the chapter).

phsyiology of pain

The physical impulses that signal pain activate various nerve pathways from the periphery to the spinal cord and to the brain. The level of stimulus needed to produce a painful sensation is referred to as the pain threshold. Because this is a measure of the physiologic response of the nervous system, it is similar for most individuals. However, variations in pain sensitivity may result from genetic factors. There are three main receptors believed to be involved in pain. The mu receptors in the dorsal horn of the spinal cord appear to play the most crucial role. Less important but still involved in pain sensations are the kappa and delta receptors. Pain receptors are located in both the central nervous system (CNS) and various body tissues. Pain perception is closely linked to the number of mu receptors. This number is controlled by a single gene, the mu opioid receptor gene. When the number of receptors is high, pain sensitivity is diminished. Conversely, when the receptors are reduced or missing altogether, relatively minor noxious stimuli may be perceived as painful. 145 The patient's emotional response to the pain is also molded by the patient's age, sex, culture, previous pain experience, and anxiety level. Whereas pain threshold is the physiologic element of pain, the psychologic element of pain is called pain tolerance. This is the amount of pain a patient can endure without its interfering with normal function. Because it is a subjective response, pain tolerance can vary from patient to patient. Pain tolerance can be modulated by the patient's personality, attitude, environment, culture, and ethnic background. Pain tolerance can even vary within the same person depending on the circumstances involved. Table 10-1 lists the various conditions that can alter one's pain tolerance

pharmacology overview anaglesics

The terms opioids and narcotics are often used interchangeably. However, the appropriate term when discussing pharmacology is opioid. Opioids are classified as both mild agonists (codeine, hydrocodone) and strong agonists (morphine, hydromorphone, oxycodone, oxymorphone, meperidine, fentanyl, and methadone). Meperidine is not recommended for long-term use because of the accumulation of a neurotoxic metabolite, normeperidine, which can cause seizures. In 2010, the mild agonist propoxyphene (Darvocet) was withdrawn from the market due to adverse effects. The opiate agonists-antagonists such as pentazocine and nalbuphine are associated with an analgesic ceiling effect. This means that the drug reaches a maximum analgesic effect, so that analgesia does not improve even with higher dosages. Such drugs are useful only in patients who have not been previously exposed to opioids and can be used for nonescalating moderate to severe pain. Finally, because of associated bruising and bleeding risks, as well as injection discomfort, there is now a strong trend away from intramuscular injections in favor of intravenous, oral, and transdermal routes of drug administration

who three step ladder

The three-step analgesic ladder defined by the World Health Organization (WHO) is often applied as the pain management standard. Step 1 is the use of nonopioids (with or without adjuvant medications) once the pain has been identified and assessed. If pain persists and/or increases, treatment moves to step 2, which is defined as the use of opioids with or without nonopioids and with or without adjuvants. If pain persists or increases, management then rises to step 3, which is the use of opioids indicated for moderate to severe pain, administered with or without nonopioids or adjuvant medications. Not all patients will be treated effectively using the ladder method, and some may need to seek an experienced pain management physician.

opioids and acute pain

The treatment of acute pain in patients who are addicted to opioids is of great concern to health care professionals, who may be reluctant to prescribe opioid therapy. However, habitual street opioid users or patients with chronic pain are opioid tolerant and generally require high dosages. Effective management of acute-on-chronic pain requires patients to receive equivalent amounts of their chronic pain medication in addition to an extra 20% to 40% more opioids to treat the acute pain. Longer-acting opioids such as methadone or extended-release oxycodone are usually better choices than shorter-acting immediate-release drug products for these patients. This is because the shorter-acting drugs are more likely to produce a psychologic "high" or euphoria, which only reinforces addictive tendencies. Genetic differences in cytochrome P-450 enzymes (see Chapters 2 and 8) can cause different patients, whether addicted or not, to respond more or less effectively to a given drug. For this reason, patients must not automatically be viewed with suspicion if they complain that a given drug does not work for them.

effective pain managment

There is no single approach to effective pain management. Instead, pain management is tailored to each patient's needs. The cause of the pain, the existence of concurrent medical conditions; the characteristics of the pain; and the psychological and cultural characteristics of the patient need to be considered. It also requires ongoing reassessment of the pain and the effectiveness of treatment. The patient's emotional response to pain depends on his or her psychologic experiences of pain. Pain results from the stimulation of sensory nerve fibers known as nociceptors. These receptors transmit pain signals from various body regions to the spinal cord and brain, which leads to the sensation of pain, or nociception

reverse opioid overdose

To reverse an opioid overdose or opioid-induced respiratory depression, an opioid antagonist, such as naloxone, must be administered. Naloxone is given intravenously in diluted form and administered slowly (such as over 15 seconds, or as ordered; see Table 10-7). However, consider the packaging and manufacturer guidelines. Emergency resuscitative equipment must always be available in the event of respiratory or cardiac arrest.

transdermal patch considerations fentanyl

Transdermal patch considerations The transdermal delivery system (patch) has been shown to be highly effective in the treatment of various chronic pain syndromes such as cancer-induced pain, especially in patients who cannot take oral medications. This route is not to be used in opioid-naïve patients or for acute pain relief. _______________ patches are difficult to titrate and are best used for nonescalating pain. _______________ patches take 6 to 12 hours to reach steady-state pain control after the first patch is applied, and supplemental short-acting therapy may be required. Most patients will experience adequate pain control for 72 hours with this method of _______________ delivery. A new patch is to be applied every 72 hours. It is important to remove the old patch when applying a new one. It takes about 17 hours for the amount of _______________ to reduce by 50% once the patch is removed. The U.S. Food and Drug Administration (FDA) has issued many safety warnings about the use of _______________ patches. _______________ patches are intended for management of chronic or cancer pain in opioid-tolerant patients whose pain is not adequately controlled by other types of medications. These patches are not to be used for acute pain situations such as postoperative pain. According to the FDA, patients who are considered opioid tolerant are those who have been taking at least 60 mg of oral morphine daily or at least 30 mg of oral oxycodone daily or at least 8 mg of oral hydromorphone daily or an equianalgesic dose of another opioid. Other hazards associated with the use of _______________ patches are cutting the patch and exposing the patch to heat (e.g., via a heating pad or sauna), both of which accelerate the diffusion of the drug into the patient's body. Unused patches should be flushed down the toilet. _______________ patches are often cut into pieces and sold on the street as "chicklets." Patients should be warned to keep all _______________ patches away from children, as deaths have occurred when toddlers inadvertently chewed _______________ patches.

nursing assessment opioid

When opioid analgesics, or any other CNS depressants, are prescribed, focus assessment on vital signs; allergies; respiratory disorders; respiratory function (rate, rhythm, depth, and breath sounds); presence of head injury (which will mask signs and symptoms of increasing intracranial pressure); neurologic status, with attention to level of consciousness or alertness and the level of sedation; sensory and motor functioning; GI tract functioning (bowel sounds and bowel patterns); and genitourinary functioning (intake and output). In addition, all opioids may cause spasms of the sphincter of Oddi. If renal and liver function studies are ordered, monitor results, because the risk for toxicity increases with diminished function of these organs. An additional concern is any past or present history of neurologic disorders such as Alzheimer's disease, dementia, multiple sclerosis, muscular dystrophy, myasthenia gravis, or cerebrovascular accident or stroke, because the use of opioids may alter symptoms of the disease process, possibly masking symptoms or worsening the clinical presentation when no actual pathologic changes have occurred. In these situations, use of another analgesic or pain protocol may be indicated. Attention to age is also important, because both older adult and very young patients are more sensitive to opioids—and holds true for many other medications. In fact, old or young age may be a contraindication to opioid use, depending on the specific drug. See the earlier pharmacology discussion regarding cautions, contraindications, and drug interactions.

general considerations

You are always responsible and accountable to maintain a current, updated knowledge base on all forms of analgesics as well as protocols for pain management with focus on the specific drug(s) as well as differences in the treatment of mild to moderate pain, severe pain, and pain in special situations (e.g., cancer pain). The WHO's three-step analgesic ladder provides a standard for pain management in cancer patients and must be reviewed and considered, as needed. Dosing of medications for pain management is very important to the treatment regimen. As noted earlier, once a thorough assessment has been performed, it is best to treat the patient's pain before it becomes severe, which is the rationale for considering pain to be the fifth vital sign. When pain is present for more than 12 hours a day, analgesic doses are individualized and are best administered around the clock rather than on an as-needed basis, while always staying within safe practice guidelines for each drug used. Around-the-clock (or scheduled) dosing maintains steady-state levels of the medication and prevents drug troughs and pain escalation. No given dosage of an analgesic will provide the same level of pain relief for every patient; thus there is a need for a process of titration—upward or even downward—to be carried out based on the individual's 166needs. Aggressive titration may be necessary in difficult pain control cases and in cancer pain situations. Patients with severe pain, metastatic pain, or bone metastasis pain may need increasingly higher dosages of analgesic. These special pain situations may require an opiate such as morphine that needs to be titrated until the desired response is achieved or until adverse effects occur. A patient-rated pain level of less than 4 on a scale of 1 to 10 is considered to indicate effective pain relief. However, this may vary depending on the health care provider, health care setting, and/or unit. If pain is not managed adequately by monotherapy, other drugs or adjuvants may need to be added to enhance analgesic efficacy. This includes the use of NSAIDs (for analgesic, antiinflammatory effects), acetaminophen (for analgesic effects), corticosteroids (for mood elevation and antiinflammatory, antiemetic, and appetite stimulation effects), anticonvulsants (for treatment of neuropathic pain), tricyclic antidepressants (for treatment of neuropathic pain and for their innate analgesic properties and opioid-potentiating effects), neuroleptics (for treatment of chronic pain syndromes), local anesthetics (for treatment of neuropathic pain), hydroxyzine (for mild antianxiety properties as well as sedating effects and antihistamine and mild antiemetic actions), or psychostimulants (for reduction of opioid-induced sedation when opioid dosage adjustment is not effective). Table 10-9 provides a listing of drugs that are not to be used in patients experiencing cancer pain.