Chapter 19: Indirect-Acting Antiadrenergic Agents

Chapter 19: Indirect-Acting Antiadrenergic Agents

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. A prescriber has ordered clonidine [Catapres] for a patient who has hypertension. The nurse teaches the patient about side effects of this drug. Which statement by the patient indicates understanding of the teaching?

a.	“I should chew sugar-free gum or drink water to reduce dry mouth.”
b.	“I should not drive as long as I am taking this drug.”
c.	“I should stand up slowly when taking this medication.”
d.	“I should stop taking this drug if I feel anxious or depressed.”

 

 

ANS:  A

Xerostomia is a common side effect of clonidine and is often uncomfortable enough that patients stop using the drug. Counseling patients to chew sugar-free gum and take frequent sips of liquid can help alleviate this discomfort. Drowsiness is common, but this side effect becomes less intense over time. Patients should be counseled to avoid hazardous activities in the first weeks of therapy if they feel this effect. The hypertensive effects of clonidine are not posture dependent, as they are with the peripheral alpha-adrenergic blockers, so orthostatic hypotension is minimal with this drug. Clonidine causes euphoria, hallucinations, and sedation in high doses and can cause anxiety or depression, although the last two effects are less common. The drug should not be stopped abruptly because of the risk of rebound hypertension, so patients experiencing unpleasant central nervous system (CNS) effects should consult their provider about withdrawing the medication slowly.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   pp. 168-169

TOP:   Nursing Process: Implementation

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

 

2. A prescriber has ordered methyldopa for a patient with hypertension. The nurse teaches the patient about drug actions, adverse effects, and the ongoing blood tests necessary with this drug. The nurse is correct to tell the patient what?

a.	“If you have a positive Coombs’ test result, you will need to discontinue the medication, because this means you have hemolytic anemia.”
b.	“Methyldopa can be used for its analgesic effects and for its hypertensive effects.”
c.	“Xerostomia and orthostatic hypotension are serious side effects and indications for withdrawing the medication.”
d.	“You will need to contact the provider and stop taking the medication if your eyes look yellow.”

 

 

ANS:  D

Hepatotoxicity is a serious adverse effect of methyldopa and is an indication for withdrawal of the drug to prevent fatal hepatic necrosis. Jaundice is a sign of liver toxicity. Patients should undergo periodic liver function tests while taking the drug. Liver function usually improves when the drug is withdrawn. A positive Coombs’ test result is not an indication for withdrawal of the drug in itself. About 5% of patients with a positive Coombs’ test result develop hemolytic anemia; withdrawal of the drug is indicated for those patients. Methyldopa does not have analgesic effects. Xerostomia and orthostatic hypotension are known side effects of methyldopa but usually are not serious.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   pp. 169-170

TOP:   Nursing Process: Planning

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

 

3. A patient complains to the nurse that the clonidine [Catapres] recently prescribed for hypertension is causing drowsiness. Which response by the nurse to this concern is appropriate?

a.	“Drowsiness is a common side effect initially, but it will lessen with time.”
b.	“You may also experience orthostatic hypotension along with the drowsiness.”
c.	“You may be at risk for addiction if you have central nervous system side effects.”
d.	“You should discontinue the medication and contact your prescriber.”

 

 

ANS:  A

CNS depression, evidenced in this patient by drowsiness, is common in about 35% of the population. These responses become less intense with continued drug use. Orthostatic hypotension is less likely with clonidine, because its antihypertensive effects are not posture dependent. The experience of drowsiness does not indicate abuse potential. The patient should not discontinue the medication abruptly because of the potential for rebound hypertension; the patient should contact the prescriber before stopping the medication.

 

PTS:   1                    DIF:    Cognitive Level: Application           REF:   pp. 168-169

TOP:   Nursing Process: Evaluation

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

 

4. A nurse is teaching nursing students about the pharmacology of methyldopa. Which statement by a student indicates the need for further teaching?

a.	“Methyldopa results in alpha2 agonist activation, but it is not itself an alpha2 agonist.”
b.	“Methyldopa is not effective until it is converted to an active compound.”
c.	“Methyldopa reduces blood pressure by reducing cardiac output.”
d.	“Methyldopa’s principal mechanism is vasodilation, not cardiosuppression.”

 

 

ANS:  C

Methyldopa does not reduce the heart rate or cardiac output, so its hypotensive actions are not the result of cardiac depression. The drug is not, in itself, an alpha₂ agonist. When taken up into brainstem neurons, it is converted into methylnorepinephrine, which is an alpha₂ agonist; it is not effective until converted to this active compound. Its hypotensive effects are the result of vasodilation, not cardiosuppression.

 

PTS:   1                    DIF:    Cognitive Level: Analysis                REF:   pp. 169-170

TOP:   Nursing Process: Implementation

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