Chapter 06: Drug Interactions

Chapter 06: Drug Interactions

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. 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.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   pp. 55-56

TOP:   Nursing Process: Assessment

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential

 

2. 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 block 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.

 

PTS:   1                    DIF:    Cognitive Level: Analysis                REF:   p. 58

TOP:   Nursing Process: Evaluation

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential

 

3. 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 beneficial, 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 adsorb other drugs onto themselves, thereby preventing absorption of the other drugs into the blood.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   p. 58

TOP:   Nursing Process: Implementation

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Reduction of Risk Potential

 

4. 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.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   pp. 56-58

TOP:   Nursing Process: Planning

MSC:  NCLEX Client Needs Category: Physiologic Integrity: Pharmacologic and Parenteral Therapies

 

5. 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.

 

PTS:   1                    DIF:    Cognitive Level: Analysis                REF:   pp. 59-60

TOP:   Nursing Process: Diagnosis