Chapter 2: Basic Concepts and Processes PrepU

The client has a diagnosis of multiple sclerosis and is taking the drug interferon beta-1a. The client takes this drug by subcutaneous injection three times a week. The dosage is 44 mcg per injection. If the client takes an injection on Monday, how many micrograms of the drug would still be in the client's system when he or she takes the next injection on Wednesday, assuming the half-life of the drug is 24 hours?

11 The half-life of a drug is the time it takes for the amount of drug in the body to decrease to one-half the peak level it previously achieved. On Tuesday, there would be 22 mcg remaining in the body. On Wednesday, 11 mcg would remain. At 12 hours before taking the next dose on Wednesday, there would be 16.5 mcg remaining. If the injection were not taken on Wednesday, 12 hours after the dose was due, there would be 5.5 mcg remaining.

A client presents to the emergency department with a drug level of 50 units/mL. The half-life of this drug is 1 hour. With this drug, concentrations above 25 units/mL are considered toxic and no more drug is given. How many minutes will it take for the blood level to reach the nontoxic range?

60 Half-life is the time required for the serum concentration of a drug to decrease by 50%. After 1 hour, the serum concentration would be 25 units/mL (50/2) if the body can properly metabolize and excrete the drug.

Mrs. Geonity is prescribed a medication, and the health care provider modifies the dose on multiple occasions to achieve the maximum therapeutic effect of the drug. The client asks the nurse what the rationale is for the dosage changes. How should the nurse respond? a. "Dosage determines whether the drug actions may be therapeutic or toxic." b. "Dosage varies based on the brand name." c. "Your generic drug does not work as efficiently, and the provider increased your dose." d. "Your HMO requires that we change the drug dose frequently."

a. "Dosage determines whether the drug actions may be therapeutic or toxic." Dosage refers to the frequency, size, and number of doses; it is a major determinant of drug actions and responses, both therapeutic and adverse. If the amount is too small or is administered infrequently, no pharmacologic action occurs, because the drug does not reach an adequate concentration at target cells. If the amount is too large or is administered too often, toxicity (poisoning) may occur. Overdosage may occur with a single large dose or with chronic ingestion of smaller doses.

The nurse understands that the dosage recommended by drug manufacturers is based on an individual weighing: a. 150 lb (68 kg). b. 100 lb (45 kg). c. 125 lb (57 kg). d. 175 lb (79 kg).

a. 150 lb (68 kg). The recommended dosage of a drug is based on drug evaluation studies and is targeted at a 150-lb (68 kg) person. As a result, clients who weigh more or less than this may require minor dosage adjustments in some cases.

The nurse is aware that it requires approximately how many half-lives for a client to excrete a medication from the body? a. 4-5 b. 10-12 c. 20-25 d. 50-100

a. 4-5 It takes five to six half-lives to eliminate approximately 98% of a drug from the body. 100/2 = 50 50/2 = 25 25/2 = 12.5 12.5/2 = 6.25 6.25/2 = 3.125 3.125/2 = 1.5625

Which client is receiving a drug that is an agonist? a. A client who takes insulin several time daily for type 1 diabetes b. A client whose depression is treated with a monoamine oxidase inhibitor (MAOI) c. A client who is taking a selective serotonin-reuptake inhibitor d. A client who takes a beta blocker for hypertension

a. A client who takes insulin several time daily for type 1 diabetes Insulin is considered an agonist because it reacts with specific receptor sites to change the cell membrane permeability, interacting directly with the receptor sites to cause the same activity that the natural chemical would cause. A monoamine oxidase inhibitor blocks the breakdown of norepinephrine by the enzyme MAO, thus being an enzyme inhibitor. A selective serotonin reuptake inhibitor is considered an enzyme inhibitor because this group of drugs acts similarly to MAO inhibitors, blocking the removal of serotonin from receptor sites. A beta blocker is an antagonist; it "blocks" receptors.

The nurse observes a Black Box warning on a chemotherapeutic agent that will be administered to a patient. What priority action should the nurse take? a. Administer the medication and assess for adverse effects. b. Do not administer this drug to the patient; it is a dangerous medication. c. Call the prescriber and inform that the medication has a Black Box warning. d. Call the pharmacy and report that the nurse is not allowed to administer drugs with Black Box warnings.

a. Administer the medication and assess for adverse effects. A Black Box warning is a method of flagging a drug so that prescribers do not miss seeing it. The warning is placed at the top of the drug label information with a black border printed around it. Printed materials and online databases that provide information about drugs all must show the warning. A Black Box warning does not meant that the drug is too dangerous to use.

A client has developed a tolerance to a drug. How should the nurse address this when providing care? a. Assess whether the client needs larger doses to achieve the effect. b. Assess the client for signs and symptoms of an allergy to the drug. c. Advocate for a change in the client's medication. d. Assess the client for signs and symptoms of adverse drug effects.

a. Assess whether the client needs larger doses to achieve the effect. With tolerance, increasingly larger doses are needed to achieve the therapeutic effect. An allergy would be manifested by reactions ranging from mild, such as a rash, to more severe, such as anaphylaxis. Although a change may be needed, tolerance typically requires an increase in dosage. To avoid the need for continually larger doses, other drugs may be added to regimen to achieve the effect. Tolerance is unrelated to adverse effects.

Dosage form is a major determinant of which drug characteristic? a. Bioavailability b. Protein-binding capacity c. Water-soluble metabolites d. Minimum effective concentration (MEC)

a. Bioavailability Dosage form is a major determinant of a drug's bioavailability (the portion of a dose that reaches the systemic circulation and is available to act on body cells). MEC, protein-binding capacity, and water-soluble metabolites are inherent characteristics of a drug that are not affected by dosage.

A client who is being treated for cancer developed a serum sickness reaction. The care team has been notified, and the client is being stabilized. What is the nurse's priority action? a. Discontinue the drug immediately as ordered. b. Administer prescribed epinephrine subcutaneously. c. Encourage the use of a MedicAlert identification. d. Administer topical corticosteroids.

a. Discontinue the drug immediately as ordered. If serum sickness occurs, the prescriber is notified and the drug is discontinued. Epinephrine is given for an anaphylactic reaction and requires a prescriber's order. A MedicAlert identification may be indicated, but is not the nurse's first concern. Topical corticosteroids may be used to treat dermatological symptoms such as rash, but would not be the nurse's first concern.

A client develops bone marrow suppression related to a drug's effects. What would be most important for the nurse to do? a. Monitor laboratory blood values. b. Place the client on protective isolation. c. Facilitate cardiac monitoring. d. Prepare the client for dialysis.

a. Monitor laboratory blood values. Monitoring blood counts would be most important for the client with bone marrow suppression. Protective isolation would be appropriate if the client were immunocompromised. Bone marrow suppression does not pose an immediate threat to cardiovascular status. Frequent mouth care would be appropriate if the client develops stomatitis. Dialysis would be indicated if the client develops renal injury due to drug therapy.

The nurse administers typical antipsychotic medications to the client who has taken these same drugs for many years. What signs and symptoms should the nurse attribute to secondary actions of the drug? Select all that apply. a. Muscular tremors b. Drooling c. Changes in gait d. Yellow discoloration of skin and sclera e. Fine red rash on the trunk

a. Muscular tremors b. Drooling c. Changes in gait Drugs that affect the dopamine levels in the brain (e.g., typical antipsychotic drugs), cause a syndrome that resembles Parkinson's disease including lack of activity, akinesia, muscular tremors, drooling, changes in gait, rigidity, extreme restlessness or "jitters" (akathisia), or spasms (dyskinesia). Yellow discoloration of the skin and sclera indicate jaundice and would suggest liver damage. A fine red rash on the trunk would be a dermatologic reaction unrelated to an antipsychotic agent's secondary effects.

A nurse has identified the half-life of drug that will be administered to a client for the first time. The nursing drug guide states the drug's half-life is 90 minutes. The nurse should identify what implication of this fact? a. Ninety minutes after drug levels peak, there will be 50% of the peak level. b. In 3 hours, there will be no detectable levels of the drug presents in the client's body. c. Drug levels will rise steadily after administration, reaching 50% of maximum concentration after 90 minutes. d. Peak drug levels will be achieved 90 minutes after the drug is administered.

a. Ninety minutes after drug levels peak, there will be 50% of the peak level. The half-life of a drug is the time it takes for the amount of drug in the body to decrease to half the peak level it previously achieved. In this case, 50% of peak levels will be achieved 90 minutes after the peak.

The nurse is caring for a client with a brain infection of bacterial etiology. When administering medications to this client, what should nurse understand about the medication delivery method required by the client's diagnosis? a. The client will require lipid-soluble antibiotics. b. The client's blood-brain barrier will not allow medications to affect brain tissue. c. Antibiotics will have to be injected directly into brain tissue. d. Active infection may destroy the integrity of the blood-brain barrier.

a. The client will require lipid-soluble antibiotics. Effective antibiotic treatment can occur only when the infection is severe enough to alter the blood-brain barrier and allow antibiotics to cross. Lipid-soluble, not water-soluble, medications cross the blood-brain barrier more easily and most antibiotics are not lipid soluble, so they are not the exception. No matter where the infection originates, drugs must cross the blood-brain barrier to treat central nervous system infections. Infection will not destroy the blood-brain barrier, which blocks drugs selectively.

A newly admitting client has signs and symptoms of an infection and the nurse anticipates that the client will be prescribed antibiotics. What assessment should the nurse prioritize when determining the client's risk for an excessive drug response due to impaired excretion? a. The client's blood urea nitrogen level and creatinine clearance rate b. The client's body mass index and hydration status c. The client's albumin, bilirubin, AST and ALT levels d. The client's fasting blood glucose level

a. The client's blood urea nitrogen level and creatinine clearance rate Renal impairment creates a risk for excessive drug responses due to delayed, or absent, excretion. This variable will likely have a greater bearing than the client's BMI, hydration status and blood glucose, though these may have an effect on pharmacokinetics. The client's hepatic status would primarily affect metabolism, not excretion.

The nurse administers an anticholinergic medication to the client. When assessing this client, what finding should the nurse interpret as a secondary effect of the drug? a. Urinary hesitancy b. Tachycardia c. Hyperthermia d. Profuse sweating

a. Urinary hesitancy Anticholinergic secondary effects include dry mouth, altered taste perception, dysphagia, heartburn, constipation, bloating, paralytic ileus, urinary hesitancy and retention, impotence, blurred vision, cycloplegia, photophobia, headache, mental confusion, nasal congestion, palpitations, decreased sweating, and dry skin. Tachycardia, hyperthermia, and profuse sweating would not be expected findings or consistent with anticholinergic effects and would require further assessment.

An experienced nurse has observed that female clients sometimes experience a drug's effects for a longer time than male clients of similar age and size. The nurse should attribute this to what factor? a. Women have more fat cells so drugs depositing in fat will have a prolonged effect. b. Men have more vascular muscle so drug effects will take longer to occur. c. Women more often experience electrolyte imbalances, prolonging a drug's effect. d. Men commonly lack certain enzyme systems that are necessary for metabolizing a drug.

a. Women have more fat cells so drugs depositing in fat will have a prolonged effect. Women have more fat cells, so drugs that deposit in fat may be slowly released and cause effects for a longer period of time. Men have more vascular muscles than women do. As a result, drugs administered to men via the IM route reach a peak level faster than they do in women. Electrolyte imbalances can affect the way a drug works on the body, however, women are not at a greater risk for electrolyte imbalances. Genetic differences, not gender, may result in either a lack of certain enzyme differences or overactivity of enzyme systems, resulting in varied responses to a drug.

The nurse is assessing a number of clients on the acute medicine unit. What client is most likely experiencing an adverse effect from the primary action of the medication? a. a client taking antihypertensives who reports dizziness upon standing b. a client whose upper gastrointestinal bleed is attributed to nonsteroidal anti-inflammatories c. a client taking oral antibiotics who has experienced nausea after each dose d. a client whose antidepressant has caused sexual dysfunction in the past

a. a client taking antihypertensives who reports dizziness upon standing Dizziness is the result of low blood pressure, which is a primary action of an antihypertensive. Nausea, sexual dysfunction and GI bleeding are secondary actions of the medications in question.

A nurse is caring for a client who has had part of her small intestine removed due to cancer. She has also now developed hypertension and has been prescribed a new medication to decrease her blood pressure. While planning the client's care, the nurse should consider a possible alteration in which aspect of pharmacokinetics? a. absorption b. distribution c. metabolism d. elimination

a. absorption Because absorption takes place mostly in the small intestine, there could be possible alterations with this process. Distribution takes place in the blood vessels; metabolism in the liver; and elimination via the kidneys. Because these systems are not affected by her surgery, these phases of pharmacokinetics would not be altered.

A client has not experienced the desired therapeutic effects of a medication. When considering factors that may affect the dynamic equilibrium that influences drug concentration, the nurse should: a. assess for factors that may reduce absorption. b. review the client's electrolyte levels. c. educate the client about drug-drug interactions. d. assess the client for adverse effects.

a. assess for factors that may reduce absorption. Reduced absorption is among that factors that contribute to the dynamic equilibrium affecting drug concentration. Electrolyte levels do not have a major effect on this dynamic equilibrium. It is important to assess for interactions and adverse effects, but these do not affect the dynamic equilibrium or concentration.

What unique characteristic is present in lipid soluble drugs? a. can cross the blood-brain barrier b. can achieve 100% bioavailability c. can achieve therapeutic drug levels d. can inhibit abnormal cellular function

a. can cross the blood-brain barrier The blood-brain barrier is composed of tight walls, limiting movement of drug molecules. This barrier makes drug therapy for the CNS difficult because drug molecules cannot pass through capillary walls. Therefore, only drugs that are lipid soluble or have an active transport system can cross the barrier and reach therapeutic levels in the brain. None of the other options are unique to lipid soluble drugs.

The nurse is caring for a group of clients and is aware that which client may require a reduction in medication dosage? (Select all that apply.) a. client with cirrhosis of the liver b. client with meningitis c. client with chronic hepatitis C d. client with cancer of the liver e. client with a hip replacement

a. client with cirrhosis of the liver c. client with chronic hepatitis C d. client with cancer of the liver Clients who have liver disorders may require decreased doses of medication because almost all medications are metabolized in the liver.

A nurse administers a prescribed loading dose of digoxin based on the understanding that doing so will result in: a. critical concentration being reached more quickly. b. enhanced absorption for effectiveness. c. prevention of drug breakdown by stomach acid. d. prolonged half-life of the administered drug.

a. critical concentration being reached more quickly. A loading dose, which is used to obtain needed effects quickly, uses a higher dose than usual to reach critical concentration. A loading dose does not enhance absorption, prevent drug breakdown by stomach acid, or prolong the half-life.

A client is diagnosed with hypercholesterolemia and is prescribed a statin. As part of client education, the nurse should teach the client to avoid eating: a. grapefruit. b. cheese. c. chicken. d. corn.

a. grapefruit. Grapefruit contains a substance that strongly inhibits the metabolism of drugs normally metabolized by the cytochrome P450 CYP3A4 enzyme. This effect greatly increases the blood levels of some drugs (e.g., the widely used "statin" group of cholesterol-lowering drugs), and the effect lasts for several days. Clients who take medications metabolized by the CYP3A4 enzyme should be advised against eating grapefruit or drinking grapefruit juice.

The nurse is administering a drug that is known to be absorbed by passive diffusion. The nurse should plan care in the knowledge that this drug will: a. move from areas of high concentration to areas of low concentration. b. require energy in order to be drawn across the cell membrane. c. enter all body cells at a similar rate, exerting a similar effect on each. d. be excreted much slower than a drug that is absorbed by active transport.

a. move from areas of high concentration to areas of low concentration. Passive diffusion occurs across a concentration gradient. When there is a greater concentration of drug on one side of a cell membrane, the drug will move through the membrane to the area of lower concentration. Such drugs do not enter every body cell and they are not excreted at different rate from drugs that use active transport. Active transport is a process that uses energy to actively move a molecule across a cell membrane.

The nurse has begun the intravenous infusion of the first dose of a client's prescribed antibiotic. A few minutes later, the client is diaphoretic, gasping for breath and has a heart rate of 145 beats per minute. After calling for help, what is the nurse's priority action? a. protecting and maintaining the patency of the client's airway b. monitoring the client's vital signs at least every five minutes c. administering intravenous antihistamines as prescribed d. providing reassurance to the client

a. protecting and maintaining the patency of the client's airway This client's presentation is suggestive of anaphylaxis. In the care team's immediate treatment, maintaining the airway is a priority. Epinephrine is administered in the short term, not antihistamines. The nurse should reassure the client, if possible, but the patency of the airway is the highest priority. Similarly, this would supersede the need for vital signs monitoring, even though this should be done.

The client is taking a drug that affects the body by increasing cellular activity. Where does this drug work on the cell? a. receptor sites b. cell membrane c. Golgi body d. endoplasmic reticulum

a. receptor sites Many drugs are thought to act at specific areas on cell membranes called receptor sites. After the receptor site is activated, this in turn activates the enzyme systems to produce certain effects, such as increased or decreased cellular activity, changes in cell membrane permeability, or alterations in cellular metabolism. Receptor sites are generally located on the outside of cells and allow the drug to bypass the cell membrane. The Golgi body and endoplasmic reticulum are not involved in this process.

Absorption of a drug administered orally will take place primarily in what anatomical location? a. small intestine b. stomach c. kidneys d. liver

a. small intestine Most oral drugs must be swallowed, dissolved in gastric fluid, and delivered to the small intestine (which has a large surface area for absorption of nutrients and drugs) before they are absorbed. The stomach focuses on the process of digestion; the kidneys and liver participate in metabolism. Absorption occurs in the small intestines.

The nurse at a campus medical clinic is administering a new medication to a 22-year-old female client. The nurse should educate the client about what potential risk of drug therapy? a. teratogenicity b. primary effects c. secondary effects d. poisoning

a. teratogenicity In a woman of childbearing age, it is important for the nurse to consider the teratogenicity of a medication because teratogens can seriously harm or injure the embryo or fetus. Primary actions, secondary actions, and poisoning would be of no greater concern with a woman of childbearing age than with any client.

How is pharmacodynamics best defined? a. the action that the drug has on body cells b. the method by which a drug is distributed through the body c. the time that elapses between absorption and excretion of a drug d. the way that the liver or kidneys alter the chemical structure of a drug

a. the action that the drug has on body cells Pharmacodynamics involves drug actions on target cells and the resulting alterations in cellular biochemical reactions and functions. Distribution, excretion, and metabolism are all aspects of pharmacokinetics.

A black male client asks the nurse why the health care provider orders a diuretic as part of his treatment plan for hypertension, when the health care provider ordered an ACE inhibitor for his friend with the same diagnosis. After consulting with the provider, how would the nurse respond? a. "Diuretics are more cost-effective." b. "Diuretics are shown to be more effective than ACE inhibitors for black males with hypertension." c. "The provider ordered diuretics to reduce the stress on your heart." d. "You must take the drug that the provider orders because the provider knows best how to manage your hypertension."

b. "Diuretics are shown to be more effective than ACE inhibitors for black males with hypertension." Most drug information has been derived from clinical drug trials using white men. Interethnic variations became evident when drugs and dosages developed for white clients produced unexpected responses, including toxicity, when given to people from other ethnic groups. One common variation is that black clients respond differently to some cardiovascular drugs. For example, for black clients with hypertension, angiotensin-converting enzyme (ACE) inhibitors and beta-adrenergic blocking drugs are less effective, and diuretics and calcium channel blockers are more effective. Also, black clients with heart failure seem to respond better to a combination of hydralazine and isosorbide than do white clients with heart failure.

A client is taking Ropinirole XR 2 mg. The drug has a half-life of 12 hours. How long will it be before only 0.25 mg of this drug is remaining in the client's system? a. 24 hours b. 36 hours c. 48 hours d. 60 hours

b. 36 hours The half-life of a drug is the time it takes for the amount of drug in the body to decrease to one-half of the peak level it previously achieved. At 12 hours there will be 1 mg of the drug available to the body. At 24 hours there will be 0.5 mg; at 36 hours there will be 0.25 mg; at 48 hours there will be 0.125 mg, and at 60 hours there will be 0.0625 mg.

What would the nurse include in the teaching plan for a client who is to receive a drug that is associated with anticholinergic effects? a. Try to stay as warm as possible to prevent chilling. b. Be sure to drink plenty of fluids to prevent dehydration. c. Avoid strenuous exercise to minimize calorie loss d. Eat a low-fiber diet to prevent constipation.

b. Be sure to drink plenty of fluids to prevent dehydration. Drugs with anticholinergic effects often cause dry mouth, constipation, dehydration, and decreased sweating. The client should be instructed to drink fluids to prevent dehydration and to avoid overly warm or hot environments. Avoiding exercise to affect calorie intake is not necessary. A high-fiber diet would be indicated to prevent constipation. Diarrhea is an anticholinergic effect.

The nurse knows that application of a topical drug on an infant's skin may result in what drug response? a. Greater concentration of drug in the infant's tissues, due to decreased body water content. b. Faster absorption of the drug because of greater surface area. c. Increased serum levels of drugs caused by decreased renal mass and glomerular filtration rate. d. Delayed and decreased metabolism of the drug caused by decreased blood flow to the liver.

b. Faster absorption of the drug because of greater surface area. An infant will have faster absorption of the topical drug because of less cutaneous fat and greater surface area. The other effects are seen in older adults.

A female client has a 12-year history of ETOH abuse. The client is injured in a motor vehicle accident and requires surgery with general anesthesia. What would the nurse expect for this client? a. a smaller-than-normal dose of the general anesthetic b. a larger-than-normal dose of the general anesthetic c. the same dose of the general anesthetic as another female of her age and medical history d. no general anesthesia, because general anesthesia should not be given to a client with her history

b. a larger-than-normal dose of the general anesthetic Drug tolerance occurs when the body becomes accustomed to a particular drug over time, so that larger doses must be given to produce the same effects. Tolerance may be acquired to the pharmacologic action of many drugs, especially opioid analgesics, alcohol, and other CNS depressants. Tolerance to pharmacologically related drugs is called cross-tolerance. For example, a person who regularly drinks large amounts of alcohol becomes able to ingest even larger amounts before becoming intoxicated; this is tolerance to alcohol. If the person is then given sedative-type drugs or a general anesthetic, larger-than-usual doses are required to produce a pharmacologic effect. This is cross-tolerance.

The nurse is assessing a client who has developed shortness of breath, a rash, panic and a blood pressure of 189/106 mm Hg after being administered a new medication. In addition to promptly informing the care team, the nurse should perform what action? a. administering monoclonal antibodies as prescribed b. administering epinephrine as prescribed c. performing cardiopulmonary resuscitation d. providing supplementary oxygen by nasal cannula

b. administering epinephrine as prescribed This client is likely experiencing anaphylaxis and requires epinephrine. There is no indication that CPR is needed. Supplementary oxygen is likely needed, but nasal cannula would likely be insufficient. Monoclonal antibodies are not used to treat anaphylaxis.

A parent brings a child to the clinic for an earache. The child receives a prescription for amoxicillin. The parent calls the clinic the next day and says the child has been taking the medicine and now has a rash. The nurse should give the parent instructions about which type of response? a. idiosyncratic response b. allergic response c. expected response d. hepatotoxic response

b. allergic response An allergic response is an immune system response. If the body interprets the drug as a foreign substance and forms antibodies against the drug, the immune system initiates the antigen-antibody response when the drug is taken again.

The nurse is caring for a client with a drug allergy and understands the allergy is the result of the client developing: a. antigens. b. antibodies. c. antihistamine. d. secondary effects

b. antibodies. Antibodies are formed by the body to react with antigens in an allergic reaction. The antigen, in this case, is the drug that the body recognizes as a foreign substance to be eliminated. Antihistamines are administered to reduce the histamines secreted as a result of the allergic reaction. An allergic reaction is distinct and different from a secondary effect.

A client is taking low-dose aspirin daily for her heart. The client is not receiving all the dosage of the aspirin that is being ingested because of: a. biotransformation. b. first-pass effect. c. liver metabolism. d. portal circulation.

b. first-pass effect. A large percentage of an oral dose is destroyed when it reaches the liver and never reaches the tissues. This phenomenon is known as the first-pass effect.

When researching information about a drug, the nurse finds that the drug tightly binds to protein. The nurse would interpret this to mean that the drug will: a. be released fairly quickly. b. have a long duration of action. c. be excreted quickly. d. lead to toxicity when given.

b. have a long duration of action. Drugs that are tightly bound to protein are released very slowly and have a very long duration of action because they are not free to be broken down or excreted. Drugs that are loosely bound tend to act quickly and to be excreted quickly. Drugs that compete with each other for protein binding sites alter the effectiveness or cause toxicity when the two drugs are given together.

What drug administration route should be used to assure the best bioavailability as any particular drug? a. oral b. intravenous c. intramuscular d. subcutaneous

b. intravenous Bioavailability refers to the portion of a dose that reaches the systemic circulation and is available to act on body cells. Drugs given via the oral, IM, and Sub-Q routes are virtually always less than 100% available because some of the drug is absorbed in the GI or liver before reaching systemic circulation. An intravenous (IV) drug is virtually 100% bioavailable. In contrast, an oral drug is virtually always less than 100% bioavailable because some of it is not absorbed from the GI tract and some goes to the liver and is partially metabolized before reaching the systemic circulation.

The triage nurse in the emergency department admits a 16-year-old boy brought in by ambulance and accompanied by a friend. The client is in respiratory distress, is vomiting, and blood is noted in the vomitus. The client is somnolent and the electrocardiogram demonstrates an arrhythmia. The friend admits that the client took a "bunch of little green pills" from the cupboard at the grandparents' house. The nurse should recognize the likelihood of what adverse reaction? a. serum sickness b. poisoning c. anaphylaxis d. delayed hypersensitivity

b. poisoning Poisoning occurs when an overdose of a drug damages multiple body systems, leading to the potential for fatal reactions. The symptoms do not indicate an anaphylactic reaction, which would not normally include bloody vomitus. Serum sickness and delayed hypersensitivity do not cause this particular presentation.

The nurse is administering medications and knows that there is a longer distribution time when the drug is intended for what area? a. heart b. skin c. liver d. kidney

b. skin A drug is distributed quickly to areas with a large blood supply, such as the heart, liver, and kidneys. However, it takes a longer period of time to be distributed to such areas as internal organs, skin, and muscles.

A nurse is administering digoxin to a client. To administer medications so that the drug is as effective as possible, the nurse should prioritize what factor? a. the client's preferences b. the process of pharmacokinetics c. educating the client about potential side effects d. the client's culture and ethnicity

b. the process of pharmacokinetics When administering a drug, the nurse needs to consider the phases of pharmacokinetics so that the drug regimen can be made as effective as possible. The client should be educating about adverse effects, but this action does not directly influence effectiveness. Similarly, the nurse must always consider clients' preferences, culture and ethnicity, but these variables are less significant than the broader process of pharmacokinetics.

The nurse is caring for a client with a gastrointestinal bleed. Which statement by the client would alert the nurse to a potential cause of the bleed? a. "I have not had much of an appetite lately." b. "When I have indigestion, I use an antacid to help with the symptoms." c. "I take aspirin a couple times a day to manage aches and pains." d. "I have noticed blood in my stools lately."

c. "I take aspirin a couple times a day to manage aches and pains." Alcohol and salicylates, such as aspirin, can both cause gastrointestinal (GI) bleeding. When a salicylate and alcohol are consumed together, the risk for GI bleeding is greatly increased because each agent independently can cause GI bleeding.

The client is a 6-year-old who is taking 125 mg of amoxicillin every 6 hours. Assuming that the half-life of amoxicillin is 3 hours, approximately how much amoxicillin would be in the child's body at the time of the next administration of the drug? a. 63 mg b. 47 mg c. 31 mg d. 16 mg

c. 31 mg The half-life of a drug is the time it takes for the amount of drug in the body to decrease to one-half the peak level it previously achieved. There would be 62.5 mg at 3 hours after the original dose of amoxicillin. There would be 46.875 mg present 4½ hours after the original dose. There would be 31.25 mg at 6 hours after the original dose. There would be 15.625 mg at 7½ hours after the original dose.

A client is receiving 250 mg of a drug that has a half-life of 8 hours. How much drug would remain after 24 hours? a. 125 mg b. 62.5 mg c. 31.25 mg d. 15.625 mg

c. 31.25 mg For each 8 hours, the drug would be reduced by one-half. Thus, after 8 hours, there would be 125 mg remaining; after the next 8 hours (16 hours later), there would be 62.5 mg (125/2) remaining; and after the next 8 hours (or 24 hours later), there would be 31.25 mg (62.5/2) remaining.

What would the nurse include in the discharge teaching for a patient who is social drinker and has been given a prescription for a narcotic analgesic? a. It is safe to drink alcohol when taking this medication. It will have no damaging effects. b. When taking your medication, if you eat something with it, you can have a drink later. c. Alcohol will potentiate the effect of the narcotic analgesic and can have a dangerous effect. d. Alcohol causes an antagonistic drug interaction and will render the narcotic analgesic less potent.

c. Alcohol will potentiate the effect of the narcotic analgesic and can have a dangerous effect. Potentiation best describes an interaction in which the effect of only one of the two drugs is increased. When alcohol and narcotics are combined, the alcohol potentiates the effect of the narcotic analgesic and can result in CNS depression.

The nurse knows that a client is at high risk for developing drug tolerance because the client will be taking which drug for a long period of time? a. Amoxicillin (Amoxil) for an infection b. Furosemide (Lasix) for edema c. Hydromorphone (Dilaudid) for pain d. Darifenacin (Enablex) for overactive bladder

c. Hydromorphone (Dilaudid) for pain Drug tolerance is a term used to describe a decreased response to a drug, requiring an increase in dosage to achieve the desired effect. It may develop when a client takes certain drugs such as opioids (hydromorphone) or tranquilizers for a long time.

What does the nurse need to do when there is any indication of an allergic reaction in clients? a. Obtain early warning of noncompliance in drug therapy. b. Increase the effectiveness of a specific medication. c. Maintain the client's safety during drug therapy. d. Reduce the risk of adverse effects during drug therapy.

c. Maintain the client's safety during drug therapy. Being alert to adverse effects, such as what to assess and how to intervene appropriately, can increase the effectiveness of a drug regimen, provide for client safety, and improve client compliance. Indications of allergic reactions would not indicate noncompliance or improve effectiveness of a specific medication. Indications of allergic reaction would indicate an adverse effect and would not reduce the risk.

An instructor is describing a specific area on a cell membrane where most drugs are thought to act. The students demonstrate understanding of this information when they identify this area as what? a. Lock b. Enzyme system c. Receptor site d. Agonist

c. Receptor site The receptor site is the area on a cell membrane where many drugs are thought to act. The process is similar to how a key works in a lock, where the chemical (the key) approaches a cell membrane and finds a perfect fit (the lock) at a receptor site. The enzyme system acts as a catalyst for various chemical reactions. An agonist is a drug that interacts directly with receptor sites to cause the same activity that natural chemicals would cause at this site.

A client has been prescribed a medication that is known to be a drug agonist. This drug will have what effect? a. It will react with a receptor site on a cell preventing a reaction with another chemical on a different receptor site. b. The drug will interfere with the enzyme systems that act as catalyst for different chemical reactions. c. The drug will interact directly with receptor sites to cause the same activity that a natural chemical would cause at that site. d. It will react with receptor sites to block normal stimulation, producing no effect.

c. The drug will interact directly with receptor sites to cause the same activity that a natural chemical would cause at that site. Agonists are drugs that produce effects similar to those produced by naturally occurring neurotransmitters, hormones, or other substances found in the body. Noncompetitive antagonists are drugs that react with some receptor sites preventing the reaction of another chemical with a different receptor site. Drug-enzyme interactions interfere with the enzyme systems that stimulate various chemical reactions.

A client is diagnosed with atrial fibrillation and prescribed the drug Coumadin (warfarin). The nurse would instruct the client to avoid what foods? a. foods with vitamin B b. foods with vitamin C c. foods with vitamin K d. foods with niacin

c. foods with vitamin K An interaction may occur between warfarin (Coumadin), an oral anticoagulant, and foods containing vitamin K. Because vitamin K antagonizes the action of warfarin, large amounts of spinach and other green leafy vegetables may offset the anticoagulant effects and predispose the person to thromboembolic disorders.

Two years ago, a client was prescribed a medication to control hypercholesterolemia. Now the health care provider prescribes a higher dose of the medication due to enzyme induction. A student nurse asks the nurse to explain the change in the drug dosage. The nurse explains that with chronic administration, some drugs stimulate liver cells to produce: a. smaller amounts of drug-metabolizing enzymes. b. toxic amounts of drug-metabolizing enzymes. c. larger amounts of drug-metabolizing enzymes. d. therapeutic amounts of drug-metabolizing enzymes.

c. larger amounts of drug-metabolizing enzymes. With chronic administration, some drugs stimulate liver cells to produce larger amounts of drug-metabolizing enzymes (called enzyme induction). Enzyme induction accelerates drug metabolism, because larger amounts of the enzymes (and more binding sites) allow larger amounts of a drug to be metabolized during a given time. As a result, larger doses of the rapidly metabolized drug may be required to produce or maintain therapeutic effects. Rapid metabolism may also increase the production of toxic metabolites with some drugs (e.g., acetaminophen). Drugs that induce enzyme production also may increase the rate of metabolism for endogenous steroidal hormones (e.g., cortisol, estrogens, testosterone, vitamin D). However, enzyme induction does not occur for 1 to 3 weeks after an inducing agent is started, because new enzyme proteins must be synthesized.

A nurse is preparing to administer a prescribed drug to a client who has liver disease. The nurse expects a reduction in dosage based on the understanding that what might be altered? a. absorption b. distribution c. metabolism d. excretion

c. metabolism The liver is the single most important site of drug metabolism. If it is not functioning properly, the drug may not be metabolized correctly and may reach toxic levels in the body. Liver disease does not affect absorption or distribution. Kidney disease would affect drug excretion.

The nurse is administering an antibiotic to a client with a diagnosis of cellulitis of the left leg. Which client condition would have the greatest effect on the drug's distribution? a. hypertension b. liver dysfunction c. peripheral vascular disease d. diverticulitis disease

c. peripheral vascular disease Distribution of a medication is affected by blood flow. Hypertension and peripheral vascular disease both impair blood flow. A client with peripheral vascular disease would have the least effective rate of drug distribution because of decreased circulation in the extremities. Diverticulitis can impact adsorption. Liver disease can impact the metabolism of the drug.

The nurse is caring for a client who experienced a severe headache. When the prescribed dose of analgesics did not cause relief the client took double the dosage 1 hour later. The nurse should assess the client for what adverse effect? a. an allergic reaction b. anaphylactic reaction c. poisoning d. sedative effects

c. poisoning This client has taken an overdosage of the medication. Poisoning occurs when an overdose of a drug damages multiple body systems, leading to the potential for fatal reactions. Allergic and anaphylactic reactions can occur with any drug administration but this is not the client's greatest risk. More information about the exact type of medication would be needed to determine whether sedative effects are likely.

Fluoxetine is given to a client at a dosage of 500 mg every 6 hours. Assuming that the half-life of this drug is 3 hours, at what point would the drug level in the body be 62.5 mg of the original dose? a. 6 hours after the original dose b. 7 hours after the original dose c. 8 hours after the original dose d. 9 hours after the original dose

d. 9 hours after the original dose The half-life of a drug is the time it takes for the amount of drug in the body to decrease to one-half of the peak level it previously achieved.

The nurse is educating the patient about potential negative effects with monoamine oxidase inhibitors (MAOIs). What type of foods should the nurse inform the patient to avoid? a. Foods high in iron b. Foods with gluten c. Foods high in vitamin D d. Foods high in tyramine

d. Foods high in tyramine Negative effects from drug interactions are those that decrease the therapeutic effect or increase the adverse effects of a drug. Consuming foods high in tyramine while taking an MAOI can lead to pronounced elevation of blood pressure and may induce a hypertensive crisis.

The nurse is caring for a client who is receiving gentamicin, 250 mg, and fluconazole, 500 mg, at the same time. What effect should the nurse anticipate if these two drugs competed with each other for protein-binding sites? a. Gentamicin will be metabolized faster than usual. b. Risks of adverse drug effects will increase. c. Potential positive benefits of each drug will cancel each other out. d. The effectiveness of both drugs will be altered.

d. The effectiveness of both drugs will be altered. Some drugs compete with each other for protein-binding sites, altering effectiveness or causing toxicity when the two drugs are given together. Metabolism will not be increased, and this does not mean the drugs' effects cancel each other out. Similarly, competition for binding sites does not result in an increased risk of adverse effects.

A 70-year-old man who enjoys good health began taking low-dose aspirin several months ago based on recommendations that he read in a magazine article. During the man's most recent visit to his care provider, routine blood work was ordered and the results indicated an unprecedented rise in the man's serum creatinine and blood urea nitrogen (BUN) levels. How should a nurse best interpret these findings? a. The man may be experiencing a paradoxical effect of aspirin b. The man may be allergic to aspirin c. The man may be experiencing liver toxicity from the aspirin d. The man may be experiencing nephrotoxic effects of aspirin

d. The man may be experiencing nephrotoxic effects of aspirin Damage to the kidneys is called nephrotoxicity. Decreased urinary output, elevated blood urea nitrogen, increased serum creatinine, altered acid-base balance, and electrolyte imbalances can all occur with kidney damage.

The nurse should consider teratogenic effects when caring for what clients? Select all that apply. a. an 81-year-old male with chronic heart failure and peripheral edema b. a 41-year-old male who is immunocompromised following bone marrow transplant c. a 44-year-old female being treated in the intensive care unit for multiorgan dysfunction syndrome d. a 29-year-old client receiving prenatal care in her first trimester of pregnancy e. a 37-year-old female client who is taking fertility drugs

d. a 29-year-old client receiving prenatal care in her first trimester of pregnancy e. a 37-year-old female client who is taking fertility drugs A teratogen is a drug that can harm the fetus or embryo so the nurse would consider the teratogenic properties of medications when caring for woman of childbearing age including adolescents and young adult women. Teratogens have no impact on clients who are not pregnant and who may not become pregnant.

The nurse is discussing medication effects with a group of peers and explains the effects of a disruption of a single step in any enzyme system. The nurse should describe what effect? a. cell death b. dissolution of the cell membrane c. reorientation of cell receptor sites d. changes in cell function

d. changes in cell function If a single step in one of the many enzyme systems is blocked, normal cell function is disrupted. Cell life and cell membrane may be impacted by disruption of some enzymes but not all enzymes. Receptor sites would not be disrupted by disruption in a single step in the enzyme system.

A client develops a skin reaction to one of their prescribed medications. This client also has a specific underlying pathology. This underlying pathology might serve as a: a. basis for planning the medication regimen. b. basis for the nursing care plan. c. prominent part of client teaching. d. contraindication for the use of certain medications.

d. contraindication for the use of certain medications. The possibility that the adverse effects can occur also accounts for the contraindications for the use of some drugs in clients with a particular history or underlying pathology. The acute problem would serve as a basis for planning the client's medication regimen and the nursing care plan. The acute problem would also be the most prominent part of client teaching.

A client is four months' pregnant. She works in the chemical unit of a research department and is responsible for handling various chemicals. Her gynecologist advised her not to expose herself to chemical or industrial vapors and specific drugs. These restrictions are advised because exposure to industrial vapors could: a. affect the eighth cranial nerve of the fetus. b. affect the liver of the fetus. c. affect the kidneys of the fetus. d. damage the immature nervous system of the fetus.

d. damage the immature nervous system of the fetus. Neurotoxicity can occur as a result of exposure to drugs and other chemicals and gases, such as industrial vapors. Immature nervous systems such as those of the fetus and neonate can easily be damaged by drugs that produce neurotoxicity. Hence, the client has been advised not to expose herself to chemical or industrial vapors and specific drugs. The liver and kidney functions and the eighth cranial nerve of the fetus are not directly affected as a result of exposure to neurotoxic substances.

A nurse has been administering a drug to a client intramuscularly (IM). The health care provider discontinued the IM dose and wrote an order for the drug to be given orally. The nurse notices that the oral dosage is considerably higher than the parenteral dose and understands that this due to: a. passive diffusion. b. active transport. c. glomerular filtration. d. first-pass effect.

d. first-pass effect. The first-pass effect involves drugs that are given PO and absorbed from the small intestine directly into the portal venous system, which delivers the drug molecules to the liver. Once in the liver, enzymes break the drug into metabolites; they may become active or may be deactivated and readily excreted from the body. A large percentage of the oral dose is usually destroyed and never reaches tissues. Oral dosages account for this phenomenon to ensure an appropriate amount of the drug in the body to produce a therapeutic action. Passive diffusion is the major process through which drugs are absorbed into the body. Active transport is a process that uses energy to actively move a molecule across a cell membrane and is often involved in drug excretion in the kidney. Glomerular filtration is the passage of water and water-soluble components from the plasma into the renal tubule.