Analgesic Drugs

What is acetaminophen?

Acetaminophen is a nonopioid analgesic found in many OTC and prescribed medications, and can be used to treat mild pain, body aches, or discomfort related to common illnesses. Care should be taken to appropriately assess the patient, properly administer the medication, and provide good education when administering acetaminophen.

What are the therapeutic uses for acetaminophen?

Acetaminophen is indicated for the relief of pain, discomfort, and fever in infants, children, adults, and older adults. Acetaminophen constitutes 25% of all OTC drugs sold. It is a safe, effective drug when used at therapeutic doses. Acetaminophen can also be combined with opioid analgesics for synergistic effects. These are controlled substances that would require a prescription.

Dosage and administration Opioid Analgesic Drug: Morphine

Adults: PO: 10-30 mg q4 hours PRN Children >6 months: PO: 0.2-0.5 mg/kg q4-6 hours PRN Infants <6 months/neonates: PO: 0.1 mg/kg q3-4 hours Adult: SR: 15-30 mg, q12 hours PRN Adult: IV/IM/subQ: 2.5-15 mg q2-6 hours PRN Children >6 months: IM/subQ: 0.05-0.2 mg/kg q2-4 hours PRN; maximum: <15 mg/dose Neonate: subQ/IM/IV: 0.03-0.05 mg/kg q4-8 hours

Contraindications for Nonopioid: Acetaminophen

Contraindications: Severe hepatic impairment or severe active liver disease Cautions: Sensitivity to acetaminophen; severe renal impairment; alcohol dependency, hepatic impairment, or active hepatic disease; chronic malnutrition and hypovolemia; G6PD deficiency (hemolysis may occur). Limit dose to less than 4 g/day.

Which agent is most likely to cause serious respiratory depression as a potential adverse reaction? Which agent is most likely to cause serious respiratory depression as a potential adverse reaction? Morphine Nalmefene Pentazocine Hydrocodone

Morphine Morphine is a strong opioid agonist and as such has the highest likelihood of causing respiratory depression. Pentazocine, a partial agonist, and hydrocodone, a moderate to strong agonist, may cause respiratory depression, but they do not do so as often or as seriously as morphine. Nalmefene, an opioid antagonist, would be used to reverse respiratory depression with opioids.

Morphine

Morphine is a strong opioid analgesic that works by binding with opioid receptors in the CNS. It has a wide variety of therapeutic uses. It is used in situations that require moderate-to-severe pain control and is effective against acute pain resulting from acute myocardial infarction (AMI) and cancer. Additionally, morphine can be used to improve comfort for patients that have dyspnea resulting from pulmonary edema, or as preoperative medication.

A patient is on a continuous infusion of morphine after surgery. Which interventions should the nurse perform?

monitor urinary output monitor respiratory rate bowel sounds

A patient with bone cancer is prescribed controlled release oxycodone for pain. The family asked the nurse when the medication should be administered. What is the nurse's best response? "Oxycodone should be given every 4 hours and as needed for breakthrough pain." "Oxycodone should be given every 2 hours and as needed for breakthrough pain." "Oxycodone should be given around-the-clock every 6 hours and as needed for breakthrough pain." "Oxycodone should be given around-the-clock every 12 hours. If the patient has breakthrough pain, call the physician."Oxycodone should be given every 4 hours and as needed for breakthrough pain." "Oxycodone should be given every 2 hours and as needed for breakthrough pain." "Oxycodone should be given around-the-clock every 6 hours and as needed for breakthrough pain." "Oxycodone should be given around-the-clock every 12 hours. If the patient has breakthrough pain, call the physician.

"Oxycodone should be given around-the-clock every 12 hours. If the patient has breakthrough pain, call the physician.

Because acetaminophen has a short half-life, it can be administered every __ hours as needed for pain relief.

4

A parent calls the health care provider and reports that her 5-year-old daughter took several acetaminophen tablets. Which intervention is appropriate?

A child who has taken an overdose of acetaminophen should be evaluated at the emergency department because of the drug's possible toxic effects on the liver.

A patient is in severe pain but is not able to swallow and does not have IV access. Which would be the best action by the nurse?

A patient in severe pain with no IV access who is not able to swallow should have morphine administered rectally.

A patient presents to the emergency department with nausea, vomiting, abdominal pain, and yellow eyes. The patient's liver function tests are elevated, and the serum acetaminophen level is 10. Which conclusion can the nurse draw?

A serum acetaminophen level of 10 is within the normal range of 5-25. The nurse can conclude that acetaminophen is not the likely cause of the patient's condition.

How is acetaminophen absorbed?

Acetaminophen is well-absorbed from the gastrointestinal (GI) tract. Rectal absorption may be erratic because of the presence of fecal material or a decrease in blood flow to the colon. Its onset of action is rapid, and the duration of action is 6 hours or less. Because of acetaminophen's short half-life, it can be administered every 4 hours as needed with a maximum dose of 4 g/day. More than 85% of acetaminophen is metabolized to drug metabolites by the liver. The therapeutic serum range is 10 to 25 mcg/mL.

A patient exhibits severe nausea and vomiting and is not able to take oral medications, but has spiked a fever and the health care provider has ordered that acetaminophen be given rectally. The nurse understands that the medication may not be absorbed properly in a patient with which condition?

Acetaminophen may be absorbed erratically in a patient with constipation because of the presence of fecal material.

Acetaminophen can be used to treat which problems?

Acetaminophen may be used for headaches, fever and moderate pain

What is the mechanism of action for acetaminophen?

Acetaminophen weakly inhibits prostaglandin synthesis, which decreases pain sensation but does not provide an anti-inflammatory effect. It also inhibits the hypothalamic heat-regulator center, providing an antipyretic effect. It is effective in eliminating mild-to-moderate pain and headaches, and for lowering fever.

Respiratory depression may be a side effect of activation of which CNS receptors?

Activation of the mu receptors may cause respiratory depression.

Dosage and administration Nonopioid Analgesic Drug: Acetaminophen

Adults and children older than 12 years or greater than 60 kg: PO/PR: 325-650 mg q4-6 hours PRN or 1 gm 3-4 times a day; maximum: 4000 mg/day. Adults and children less than 60 kg: PO/PR: 10-15 mg/kg q4-6 hours PRN; maximum: 75 mg/kg/day

Which medications are part of the amphetamine family of drugs? Select all that apply. Amphetamine Lisdexamfetamine Methamphetamine Dystroamphetamine Dextroamphetamine

Amphetamine Lisdexamfetamine Methamphetamine Dextroamphetamine

A patient in the emergency department has mild pain and asks for acetaminophen. Which intervention by the nurse is most appropriate?

Asking a patient about use of acetaminophen earlier in the day is important prior to administering the drug again, as there is a limit to how much can safely be taken in one day.

The nurse is caring for a patient with attention-deficit/hyperactivity disorder (ADHD) who has a history of stimulant abuse. Which treatment does the nurse anticipate the health care provider will prescribe? Caffeine Bupropion Atomoxetine Desipramine

Atomoxetine

What is true about atomoxetine? Select all that apply. <p>What is true about atomoxetine? <b>Select all that apply.</b> </p> Atomoxetine has a low potential for abuse. Atomoxetine is a central nervous system stimulant. Atomoxetine takes 1 to 3 weeks for maximal response. Atomoxetine is given by means of a transdermal patch. Atomoxetine may cause suicidal thinking in children and adolescents.

Atomoxetine has a low potential for abuse. Atomoxetine takes 1 to 3 weeks for maximal response. Atomoxetine may cause suicidal thinking in children and adolescents.

Which statement correctly identifies pharmacologic properties of acetaminophen?

Because acetaminophen is a nonopioid analgesic but not an NSAID, it is used for the treatment of mild to moderate pain but is not used as an anti-inflammatory.

Which statements about caffeine does the nurse identify as true? Select all that apply. <p>Which statements about caffeine does the nurse identify as true? Select all that apply. Caffeine is a diuretic. Caffeine promotes bronchodilation. Caffeine promotes constriction of cerebral blood vessels. Caffeine reduces the capacity for prolonged intellectual exertion. Caffeine can restore mental functioning during alcohol intoxication.

Caffeine is a diuretic. Caffeine promotes bronchodilation. Caffeine promotes constriction of cerebral blood vessels.

Contraindications for Opioid: Morphine

Contraindications: Hypersensitivity, CNS or respiratory depression, status asthmaticus, increased intracranial pressure, shock, alcoholism, ileus, and hypovolemia. Cautions: Respiratory insufficiency, renal, or hepatic diseases; urinary retention, sleep apnea; and older adults.

The nurse instructs the patient about the use of amphetamines for narcolepsy. What is included in this teaching? Select all that apply. <p>The nurse instructs the patient about the use of amphetamines for narcolepsy. What is included in this teaching? <b>Select all that apply.</b> </p> Do not suddenly stop medication. Monitor blood pressure and weight. Increased somnolence is expected. There is a high potential for abuse and dependence. Take only as directed to produce a state of paranoid psychosis.

Do not suddenly stop medication. Monitor blood pressure and weight. There is a high potential for abuse and dependence.

The nurse is assessing a patient who underwent surgery and has been prescribed oxycodone. The patient complains of constipation. Which medicine does the nurse expect in the healthcare provider's prescription? Docusate Naloxone Meperidine Tapentadol

Docusate Oxycodone is an opioid drug, which may decrease peristalsis because of its depressive effect on the central and peripheral nervous systems, which can result in constipation. Therefore, stool softeners such as docusate, often given with an osmotic laxative, should be prescribed to the patient. Naloxone is an opioid antagonist and is used in opioid toxicity. It may not completely relieve constipation in the patient. Meperidine is an opioid drug, is not helpful for the management of constipation, and may worsen it. Tapentadol is an opioid drug that would worsen constipation.

Interactions for Opioid Analgesic Drug: Morphine

Drug: Increases effects of alcohol, sedative-hypnotics, antipsychotic drugs, and muscle relaxants. Herbal: St. John's wort may decrease effect of morphine. Lab: Increases aspartate aminotransferase (AST) and alanine aminotransferase (ALT).

Evaluations for Morphine

Evaluate the effectiveness of morphine in lessening or alleviating pain. If pain persists after several days, dose should be increased or the opioid changed. Determine stability of vital signs. Any decrease in respiration and blood pressure should be reported.

Patient Teaching for Morphine

General Teaching Encourage patients not to use alcohol or CNS depressants with any opioid analgesics, such as morphine. Respiratory depression can result. Suggest nonpharmacologic measures to relieve pain as patient recuperates from surgery. As recovery progresses, a nonopioid analgesic may be prescribed. Alert patients that with continuous use, opioids such as morphine can become addicting. If addiction occurs, inform patients about methadone treatment programs and other resources in the area. Side Effects Encourage patients to report dizziness while taking morphine. Dizziness could be due to orthostatic hypotension. Advise patients to ambulate with caution or only with assistance to prevent falls. Notify patients that opioids can cause constipation. Encourage patients to increase fiber and fluid intake, and tell them to notify the health care provider if the problem persists or becomes severe. Teach patients to report difficulty in breathing, blurred vision, and headaches.

Patient Teaching for Acetaminophen

General Teaching Teach patients to keep acetaminophen out of children's reach. Acetaminophen for children is available in flavored tablets and liquid. High doses can cause and overdose, resulting in hepatotoxicity. Advise patients not to self-medicate with acetaminophen longer than 10 days. Teach adult caregiver not to medicate child longer than 5 days without health care provider's approval. Direct parents to call poison control center immediately if a child has taken a large or unknown amount of acetaminophen. Teach patients to check acetaminophen dosage on package label of any OTC drug. Because many OTC remedies (especially combination cold medications) contain acetaminophen, it is easy to accidentally overdose. Do not exceed the recommended dosage. Suggested safe adult acetaminophen dose is 2000 mg/d (2 g/day), not to exceed 4 g/day to avoid liver damage. Inform patients to avoid alcohol. Side Effects Encourage patients to report side effects. Overdosing can cause severe liver damage and death. Inform patients to report any signs of liver toxicity including, but not limited to, fatigue, weight loss, nausea, vomiting, confusion, and yellow discoloration of the skin (jaundice).

Low-caffeine food sources (less than 20 mg) include which foods? Select all that apply. <p>Low-caffeine food sources (less than 20 mg) include which foods? <b>Select all that apply.</b> </p> Herbal tea (8 oz) Brewed tea (8 oz) Orange soda (12 oz) Instant coffee (8 oz) Milk chocolate bar (1.5 oz)

Herbal tea (8 oz) Milk chocolate bar (1.5 oz)

Adverese Effects Opioid Analgesic Drug: Morphine

Hypotension, urticaria, seizures, and ileus Life-threatening: Respiratory depression

Interactions for Nonopioid Analgesic Drug: Acetaminophen

Increase effect of acetaminophen with caffeine and diflunisal Decrease effect of acetaminophen with oral contraceptives, antacids, anticholinergics, cholestyramine, charcoal, barbiturates, carbamazepine, and phenytoin

The nurse is educating a patient who has been prescribed methylphenidate for narcolepsy. What potential adverse effects should the nurse include in the patient teaching? Select all that apply. <p>The nurse is educating a patient who has been prescribed methylphenidate for narcolepsy. What potential adverse effects should the nurse include in the patient teaching? <b>Select all that apply.</b> </p> Insomnia Headache Weight loss Increased appetite Decreased blood pressure

Insomnia Headache Weight loss

Interventions and Evaluation for Acetaminophen

Interventions Administer as needed for pain. Round-the-clock dosing may be most effective. Monitor total dose given so as not to exceed 4000 mg/day. Check liver enzyme tests such as alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, 5'nucleotidase, and bilirubin for elevations in patients taking high doses or overdoses of acetaminophen. Check serum acetaminophen level if toxicity is suspected. Normal serum level is 5 to 25 mcg/mL; toxic level is >200 mcg/mL and could indicate hepatotoxicity. The antidote for acetaminophen is acetylcysteine. Dosage is based on serum acetaminophen level. Evaluation Evaluate the effectiveness of acetaminophen in relieving pain. If pain persists, another analgesic may be needed. Observe and report any side effects.

Interventions or Morphine

Interventions Administer morphine before pain reaches its peak to maximize effectiveness of the drug. Monitor vital signs at frequent intervals to detect respiratory changes. Respirations of <10/minute can indicate respiratory distress. Record patient's urine output because urinary retention is a side effect of morphine. Urine output should be at least 600 mL/day. Check bowel sounds for decreased peristalsis; constipation is a side effect of morphine. Dietary change or mild laxative might be needed. Check for pupil changes and reaction. Pinpoint pupils can indicate morphine overdose. Have naloxone available as an antidote to reverse respiratory depression if morphine overdose occurs. Use side rails, and take other safety precautions as necessary to prevent falls.

Cultural Considerations in Analgesic Meds

Involving the extended family may be important for teaching health strategies and providing support. Identify conflicts in values and beliefs about pain and its management. Respect cultural and religious differences concerning refusal of opioid analgesics. Incorporate traditional practices into Western medicine when possible.

A patient is admitted to the drug rehabilitation unit for treatment of opioid addiction. The nurse would anticipate administration of which medication? Morphine Naloxone Methadone Meperidine

Methadone

For what circumstances are central nervous system (CNS) stimulants indicated? Select all that apply. Insomnia Narcolepsy Seizure disorder Hypothyroid disorder Attention-deficit/hyperactivity disorder (ADHD)

Narcolepsy Attention-deficit/hyperactivity disorder (ADHD)

Nonopioid analgesics

Nonopioid analgesics (aspirin, acetaminophen, ibuprofen, and naproxen) are less potent than opioid analgesics. They are used to treat mild to moderate pain. Many of the same nonopioid analgesics that are taken for pain, such as the nonsteroidal anti-inflammatory drugs (NSAIDs), are also taken for anti-inflammatory purposes. Nonopioids are usually purchased over-the-counter (OTC), but COX-2 inhibitors require a prescription. Nonopioids are effective for the dull, throbbing pain of headaches, dysmenorrhea (menstrual pain), inflammation, minor abrasions, muscular aches and pain, and mild-to-moderate arthritis. Most analgesics also have an antipyretic effect and will lower an elevated body temperature.

Pre-admission assessment for Nonopioid: Acetaminophen

Obtain a medical history of liver dysfunction. Overdosing or extremely high doses of acetaminophen can cause hepatotoxicity. Ascertain the severity of pain. Nonopioid NSAIDs, such as ibuprofen, may be sufficient to relieve pain or an opioid may be necessary. If given for analgesia, assess onset, type, location, duration of pain. Effect of medication is reduced if full pain response recurs prior to next dose. Assess for fever. Assess alcohol usage.

Pre-admission assessment for Opioid: Morphine

Obtain a medical history, including history of drug or alcohol abuse. Determine a medication history. Report if a drug-drug interaction is probable. Morphine increases the effects of alcohol, sedatives or hypnotics, antipsychotic drugs, and muscle relaxants, and might cause respiratory depression. Assess vital signs, noting rate and depth of respirations for future comparisons; opioids commonly decrease respirations and systolic blood pressure. Assess type of pain, location, and duration. Validate dose of morphine before its administration. Check older adults for alertness and orientation because confusion is a side effect of morphine.

Adverse Effects on Nonopioid Analgesic Drug: Acetaminophen

Oliguria, urticaria, and elevated liver enzymes Life-threatening: Hemorrhage, hepatotoxicity, hemolytic anemia, agranulocytosis, leukopenia, thrombocytopenia, and chronic kidney disease

Opioid analgesics aka opioid agonists

Opioid analgesics, called opioid agonists, are prescribed for moderate and severe pain. Morphine, a prototype opioid, is obtained from the sap of seedpods from the opium poppy plant. Codeine is another drug obtained from the opium poppy. In the past decades, many synthetic and semisynthetic opioids have been developed. Meperidine is an example of a synthetic opioid. While nonopioid analgesics act on the peripheral nervous system at the pain receptor sites, opioid analgesics act mostly on the CNS. Opioids act primarily by activating the µ receptors, while also exerting a weak activation of the kappa (κ) receptors. Analgesia, respiratory depression, euphoria, and sedation are effects of µ activation. Activation of κ receptors leads to analgesia and sedation, having no effect on respiratory depression and euphoria. Opioids, such as morphine, not only suppress pain impulses, but also suppress respiration and coughing by acting on the respiratory and cough centers in the medulla of the brainstem.

What pharmacokinetic trait is most important to consider with oral morphine administration?

Oral morphine undergoes first hepatic pass, meaning it must be metabolized by the liver before it becomes available to the rest of the body.

Administration of Morphine

Parenterally the onset of action is rapid, especially when administered by the IV route. Onset of action is slower for subcutaneous (subQ) and intramuscular (IM) injections. Duration of action with most types of drug administration is 3 to 5 hours; duration of action is 8 to 12 hours with controlled-release morphine sulfate tablets. Morphine may be taken orally, although GI absorption can be somewhat erratic. For severe pain, such as with AMI, it is given intravenously. Morphine is 30%-35% protein-bound and may also be administered rectally and epidurally. Oral morphine undergoes first hepatic pass, meaning the liver metabolizes the drug before bioavailability to the rest of the body occurs. Only a small amount of morphine crosses the blood-brain barrier to produce an analgesic effect. It has a short half-life, and 90% is excreted in the urine. Morphine crosses the placenta and is excreted in breast milk.

Which statements are true about modafinil? Select all that apply. <p>Which statements are true about modafinil? <b>Select all that apply.</b> </p> It is a Schedule II substance. Physical withdrawal has not been reported. Physical dependence has not been reported. Approved uses are for insomnia and hyperthyroidism Modafinil has many off-label uses, such as for the treatment of jet lag and attention-deficit/hyperactivity disorder (ADHD).

Physical withdrawal has not been reported. Physical dependence has not been reported. Modafinil has many off-label uses, such as for the treatment of jet lag and attention-deficit/hyperactivity disorder (ADHD).

Which factor will the nurse consider while planning pharmacologic therapy for a patient with pain? Analgesics should be administered as needed to minimize adverse effects. Relief of chronic pain is best obtained by administering analgesics around the clock. Patients should request analgesics when the pain level reaches a 3 on a scale of 1 to 10. Narcotic analgesics should not be used for more than 24 hours because of the risk of addiction.

Relief of chronic pain is best obtained by administering analgesics around the clock.

A nurse working with patients who are diagnosed with attention-deficit/hyperactivity disorder (ADHD) knows such patients often take central nervous system (CNS) stimulant drugs. These medications are potent, with a high potential for abuse and dependence. Based on this potential, how are these medications classified? <p>A nurse working with patients who are diagnosed with attention-deficit/hyperactivity disorder (ADHD) knows such patients often take central nervous system (CNS) stimulant drugs. These medications are potent, with a high potential for abuse and dependence. Based on this potential, how are these medications classified?</p> Schedule I Schedule II Schedule III Schedule IV

Schedule II

A patient has been taking morphine frequently after her recent surgery. The nurse would most likely suggest ordering which laboratory test?

The transaminases AST and ALT may become elevated with morphine use and should be monitored via liver function panel.

A patient is admitted for repair of a fractured wrist. The patient has a history of opioid addiction. Which medication does the nurse anticipate the physician to order for the patient's pain? Tramadol Hydrocodone Oxycodone/aspirin Oxycodone/acetaminophen

Tramadol

Tolerance

a state in which a larger dose is required to produce the same response that could formerly be produced with a smaller dose.

Which are questions the nurse should ask a patient who is using acetaminophen?

how often do you drink alcohol do you have a history of liver disease

Opioids primarily activate the mu receptors, causing which effects?

sedation, euphoria and analgesia

A patient is recovering from surgery and wishes to avoid taking morphine if possible. Which intervention by the nurse is most appropriate?

the nurse should encourage all postoperative patients to use nonpharmacologic measures to relieve pain.