CHAPTER 06 - Practice Questions

The nurse reviews all of the patient's prescriptions. Which prescribed medications may cause a detrimental potentiative drug interaction? a. aspirin and warfarin b. propranolol and albuterol c. sulbactam and ampicillin d. isoniazid and rifampin

ANS: A Aspirin and warfarin both suppress clotting. As a result, if aspirin and warfarin are taken concurrently, the risk of bleeding is significantly increased.

muscle pain from the adverse effect of rhabdomyolysis is possible if a patient who is prescribed which drug does not inform the prescriber that the patient drinks grapefruit juice? a. Lovastatin (Mevacor) for high cholesterol b. Nifedipine (Procardia) for hypertension c. Triazolam (Halcoin) for insomnia d. Verapamil (Calan) for atrial fibrillation

ANS: A

the nurse is providing discharge teaching for a patient who will be taking metronidazole (Flagyl) after discharge. the drug information states to caution the patient that a reaction similar to the action of disulfiram (Antabuse) can occur. it is a priority to teach the patient to avoid which food or drink? a. beer b. chocolate c. high-fat food d. sugar

ANS: A

The nurse is concerned with minimizing adverse drug-drug interactions for the patient. Which drug characteristic could result in the most serious consequences from a drug-drug interaction? a. low therapeutic range b. low potency c. first-pass effect d. high biologic half-life

ANS: A Interactions are especially important with drugs that have a narrow therapeutic range, because an interaction that produces a modest increase in drug levels can cause toxicity.

Which statement about food and drug interactions is true? a. Foods alter drug absorption and metabolism but not drug action. b. Medications are best absorbed on an empty stomach. c. Patient discomfort is the food and drug interaction of most concern. d. Some foods can inhibit CYP isoenzymes and alter drug metabolism.

ANS: D Grapefruit juice inhibits CYP3A4, which lowers the metabolism of some drugs, leading to toxic effects of drugs affected by these isoenzymes. Foods can alter all pharmacokinetic and pharmacodynamic processes. Not all medications are absorbed better on an empty stomach; some require certain foods to enhance absorption. Patient discomfort is a concern, but it is not as important as more severe and possibly life-threatening food and drug interactions.

Before administrating the dosage of a prescribed medication, the nurse observes precipitation formation of the intravenous (IV) solution. What is the priority nursing action? a. verify the prescription b. prepare another dose to administer c. check the expiration date of the drug d. discard the IV solution

ANS: D If a precipitate appears in the IV solution, that solution should be discharged.

Which response would the nurse anticipate when giving two drugs that have a potentiative effect, such as meperidine and Phenergan? a. increased pain relief b. decreased itching c. increased nausea and vomiting d. increased alertness

ANS: A A potentiative effect occurs when one drug intensifies the effects of another. An inhibitory effect would cause reduced therapeutic effects or reduced adverse effects. Potentiative effects are not unique responses. Meperidine is a morphine derivative for pain relief. Phenergan is an antiemetic that potentiates the effect of meperidine. The patient should experience decreased pain and also may be drowsy.

A nurse is teaching a patient about a drug that induces P-glycoprotein. The nurse will explain that this drug may cause which effect on other drugs? a. Decreased absorption in the intestines b. Decreased elimination through the kidneys c. Increased brain exposure d. Increased fetal absorption

ANS: A Drugs that induce PGP can increase export from cells of the intestinal epithelium into the intestinal lumen, thus decreasing absorption of the drug. PGP inducers also increase drug elimination and decrease brain and fetal drug exposure.

The nurse is teaching a patient prescribed felodipine [Plendil] for the treatment of hypertension. Which statement is the most appropriate for the nurse to include in the teaching session? a. "Avoid grapefruit juice while you are taking this medication." b. "Herbal agents can help this drug work more effectively." c. "Do not eat foods high in tyramine such as aged cheese." d. "This drug is free of dangerous drug interactions."

ANS: A Grapefruit juice can raise levels of felodipine by as much as 406% because of the effect grapefruit juice has on the CYP3A4 isoenzyme.

In a discussion of drug-drug interactions, which would be the best example of a beneficial inhibitory interaction? a. Naloxone [Narcan] blocking morphine sulfate's actions b. Antacids blocking the action of tetracycline [Sumycin] c. Propanolol [Inderal] blocking the effects of albuterol d. Cholestyramine blocking the actions of antihypertensive drugs

ANS: A Naloxone is used when a narcotic overdose has occurred. As a narcotic antagonist, it provides a beneficial inhibitory interaction. An antacid blocking tetracycline's antibiotic effects would not be baneful, but rather detrimental to the desired effects of the tetracycline. Alcohol would not block the effects of opiates, but would contribute to CNS depression. Cholestyramine and certain other adsorbent drugs, which are administered orally but do not undergo absorption, can absorb other drugs onto themselves, thereby preventing absorption of the other drugs into the blood.

The nurse is preparing a discharge teaching plan to a patient prescribed phenobarbital and oral contraceptives which are known to induce CYP isoenzymes. What patient teaching should the nurse include in the discharge plan? a. "Plan to use another form of birth control while taking phenobarbital." b. "Your dose of birth control pills will be reduced while you are taking phenobarbital." c. "Continue taking your medications as prescribed." d. "Condoms are not necessary while taking phenobarbital. It is not an antibiotic."

ANS: A Phenobarbital induces CYP isoenzymes; therefore, it will increase the metabolism of other drugs. Because phenobarbital is an inducing agent, it will increase the metabolism of oral contraceptives. The nurse should anticipate that this will likely reduce the blood levels of birth control pills. The patient should use another form of birth control while taking phenobarbital.

The nurse is providing multiple medications to a patient whose spouse brings grapefruit juice every morning. The nurse will be concerned about which classes of drugs? (Select all that apply.) a. Calcium channel blockers b. Selective serotonin reuptake inhibitors c. Aminoglycosides d. Beta blockers e. Penicillins

ANS: A, B Calcium channel blockers and selective serotonin reuptake inhibitors have been shown to reach increased and/or toxic levels when taken with grapefruit juice. Grapefruit juice is not contradicted with aminoglycosides, beta blockers, or penicillins.

A nurse is caring for a patient who is taking multiple medications. To help ensure that adverse drug reactions are prevented or minimized, the nurse will do which of the following? (Select all that apply.) a. Ask the patient about over-the-counter medications used. b. Contact the prescriber to request cytochrome P450 levels. c. Limit the patient's calcium intake. d. Obtain a thorough diet history. e. Request orders for PRN medications to treat any anticipated symptoms of drug interactions.

ANS: A, B, D Over-the-counter medications add to drug interactions, and a thorough history of all medications taken by the patient is essential to minimize adverse drug reactions. Cytochrome P450 levels yield important information about a patient's ability to metabolize drugs and can help predict whether drugs will reach toxic levels or be ineffective. A diet history allows providers to anticipate significant known food-drug interactions. Limiting calcium intake is necessary only if the patient is taking drugs known to interact with calcium, such as tetracycline. Asking for PRN medications to treat drug reactions may only compound the risk, because the risk of the drug interactions increases with the number of medications taken.

The nurse is administering morning mediations. The nurse gives a patient multiple medications, two of which compete for plasma albumin receptor sites. As a result of this concurrent administration, the nurse can anticipate that what might occur? (Select all that apply.) a. Binding of one or both agents will be reduced. b. Plasma levels of free drug will rise. c. Plasma levels of free drug will fall. d. The increase in free drug will intensify effects e. The increase in bound drug will intensify effects.

ANS: A, B, D When two drugs bind to the same site on plasma albumin, coadministration of those drugs produces competition for binding. As a result, binding of one or both agents is reduced, causing plasma levels of free drug to rise. The increase in free drug can intensify the effect, but it usually undergoes rapid elimination. The increase in plasma levels of free drug is rarely sustained.

The prescriber has ordered an antibiotic for a patient with a bacterial infection. The nurse provides patient education at discharge and instructs the patient to take the drug on an empty stomach. When should the patient take the drug? (Select all that apply.) a. 1 hour or more before a meal b. Only after an 8-hour fast c. Only after the patient has missed a meal d. At least 2 hours after a meal e. Shortly before a meal

ANS: A, D The absorption of some drugs can be significantly reduced by food; these drugs should be taken on an empty stomach, which is 1 hour or more before a meal or at least 2 hours after a meal. An 8-hour fast is not necessary; the patient does not need to miss a meal total the medication; and it is not reasonable to have the patient on thin liquids for 12 hours.

a patient has been taking phenytoin (Dilantin), a drug with a narrow therapeutic index, to control seizures. if fenobibrate (Tricor) is prescribed to lower triglycerides, drug interaction puts the patient at risk for which effect? a. excessively low triglycerides b. seizures c. toxicity from the fenobibrate (Tricor) d. toxicity from the phenytoin (Dilantin)

ANS: B

A nurse is teaching a patient about a prescription for a monoamine oxidase (MAO) inhibiter for depression. What will the nurse teach the patient to avoid while taking this drug? a. Alcoholic beverages b. Aged cheeses c. Brussel sprouts and cabbage d. Grapefruit juice

ANS: B Aged cheeses are rich in tyramine, which interacts with MAO inhibitors to raise blood pressure to life-threatening levels. Patients taking MAO inhibitors should be taught to avoid tyramine-rich foods. Chianti wine contains tyramine, but other alcoholic beverages do not. Brussel sprouts and cabbage are foods rich in vitamin K, which can interfere with the effects of warfarin. Grapefruit juice inhibits CYP3A4 and interferes with the metabolism of many medications.

A patient taking oral contraceptives thinks she may be pregnant. As part of this patient's history, what will the nurse ask the patient? a. "Do you drink grapefruit juice?" b. "Do you take seizure medication?" c. "Do you take your contraception with milk?" d. "Do you use laxatives regularly?"

ANS: B Patients taking oral contraceptives along with phenobarbital, which is used to treat seizures, will have lower levels of the contraceptive, because phenobarbital is an inducing agent, which causes an increase in the metabolism of oral contraceptives. Grapefruit juice inhibits the metabolism of some drugs, leading to toxic effects. Dairy products interfere with the absorption of tetracyclines, because the calcium binds with the drug to form an insoluble complex. Laxatives reduce the absorption of some drugs by speeding up the transit time through the gut.

a patient has been prescribed sildenafil (Viagra) for erectile dysfunction. the nurse teaches the patient that metabolism of this drug may be increased, possibly decreasing the effect, if the patient uses which dietary supplement? a. fish oil b. iron c. garlic d. multivitamin

ANS: C

patients receiving certain drugs that are metabolized by the CYP3A4 enzyme should not drink grapefruit juice because grapefruit juice inhibits the CYP3A4 enzyme and the drug transporter p-glycoprotein. the patient asks what might happen if she drinks grapefruit juice and takes the medication. the nurse's response is based on knowledge that the effect could be what? a. lack of response because the drug will not be absorbed b. lack of response because it does not get to the site of action c. impaired metabolism and excretion of the drug d. liver damage because the CYP3A4 enzyme destroys the liver

ANS: C

tobacco induces the CYP1A2 liver enzyme. methadone is metabolized by the CYP1A2 liver enzyme. if a drug-addicted patient was treated with methadone and smoked cigarettes, what would this tobacco use be expected to do? a. diminish the effect of methadone b. make the effect of methadone more intense c. speed the elimination of methadone d. slow the elimination of methadone

ANS: C

A young adult postoperative patient is receiving morphine 2 to 4 mg IV every 2 hours PRN pain. The last dose was 3 mg given 2 hours ago. The patient is asleep, and the nurse notes a heart rate of 86 beats per minute and a respiratory rate of 8 breaths per minute. Which PRN medication will the nurse give this patient? a. Diphenhydramine [Benadryl] to counter morphine side effects b. Morphine 4 mg for increased pain, as indicated by tachycardia c. Naloxone [Narcan] to blok the effects of the morphine d. Nothing at this time, because the patient is resting comfortably

ANS: C A respiratory rate of 8 breaths per minute indicates respiratory depression, which is a significant adverse effect indicating morphine toxicity. Naloxone blocks the actions of morphine at cell receptor sites and is given to quickly reverse the effects. This patient does not have signs of an allergic response, which would include shortness of breath, a rapid respiratory rate, and wheezing. The tachycardia might be a sign of worsening pain, but the toxic effects must be treated first. Patients who are sleeping are not always pain free.

A patient is taking drug X and receives a new prescription for drug Y, which is listed as an inducing agent. The nurse caring for this patient understands that this patient may require ____ doses of drug ____. a. lower; X b. lower; Y c. higher; X d. higher; Y

ANS: C An inducing agent stimulates the synthesis of CYP isoenzymes, which may increase the metabolism of other drugs as much as two- to threefold, thereby lowering the level of those drugs in the body and requiring higher doses to maintain drug effectiveness.

The drug the nurse is about to give induces P-glycoprotein (PGP). Which outcome should the nurse expect when this drug is given with other drugs? a. reduced drug elimination b. increased levels of other drugs c. reduced absorption of other drugs d. increased side effects of other drugs

ANS: C Drugs that induce PGP can cause reduced absorption of other drugs, which would reduce their levels. A PGP inducer would not increase the side effects of other drugs and could increase elimination of other drugs.

a male patient is prescribed clopidogrel (Plavix) to prevent blood clots after experiencing a myocardial infarction. he self-prescribes omeprazole (Prilosec OTC) for heartburn. because omeprazole can inhibit the efficacy of clopidogrel, it is a priority for the nurse to teach the patient to report which effect? a. dizziness b. nausea and vomiting c. joint pain d. sudden shortness of breath or chest pain

ANS: D

it is the nurse's responsibility at this institution to decide what time a drug will be administered. Cholestyramine (Questran) has been prescribed for a patient who takes many drugs for diabetes and hypertension. the patient takes the other drugs at 0900 and 1700. at this institution, drugs can be given up to 1 hour before or after the assigned time. based on proper timing of administration of this drug, when should the cholestyramine be administered? a. 0800 b. 0900 c. 1000 d. 1100

ANS: D

The nurse is teaching a patient about taking warfarin and asks if the patient takes aspirin. This assessment by the nurse reflects a knowledge of which type of drug interaction? a. Creation of unique effects b. Increased therapeutic effects c. Inhibitory effects d. Potentiative effects

ANS: D A potentiative effect is one in which one drug intensifies the effects of another. Both warfarin and aspirin suppress blood clotting, and the combination may increase the risk of bleeding, which is an intensified adverse effect. Creation of a unique effect is a rare occurrence in which the combination of two drugs creates a response not seen with either drug when given alone. Increased therapeutic effects are a type of potentiative effect; however, in this case the combination of two drugs would increase the desired effects. An inhibitory effect is a type of pharmacodynamic effect that occurs when an antagonist drug inhibits the action of an agonist drug at the same receptor site.

A child ingests a parent's aspirin tablets, and the prescriber orders sodium bicarbonate to block the toxic effects of the aspirin. The nurse caring for this patient knows that sodium bicarbonate is effective against the aspirin because it: a. accelerates its passage through the intestine. b. alters urinary pH to enhance renal excretion. c. induces CYP isoenzymes to increase drug metabolism. d. raises the pH of the intestinal fluid to facilitate passage out of the cells.

ANS: D Sodium bicarbonate increases the pH of interstitial fluid and plasma, allowing the acidic aspirin ions to move outside the cells and thus removing them from the site where they have toxic effects. It does not have laxative effects and does not alter the rate of passage through the gut. It is not a CYP isoenzyme inducer and therefore has no effect on drug metabolism. It does not alter renal excretion of aspirin.