Correct Answer: B

Rationale: Prothrombin time (PT) and international normalized ratio (INR) are crucial laboratory values to monitor the effectiveness of warfarin therapy in clients with atrial fibrillation. These values help ensure that the client is within the therapeutic range and that the anticoagulant effect of warfarin is appropriate.

Correct Answer: A

Rationale: The correct instruction for a client taking digoxin is to monitor the pulse before each dose and hold the medication if the pulse is below 60 beats per minute. Digoxin can cause bradycardia, so it is crucial to assess the pulse rate before administration to prevent potential complications.

Correct Answer: C

Rationale: Atenolol is a beta-blocker that commonly causes hypotension by lowering blood pressure. Therefore, monitoring for hypotension is crucial to prevent potential complications in the client receiving this medication.

Correct Answer: A

Rationale: Enalapril, an ACE inhibitor, can lead to hypotension, particularly following the initial dose or dosage escalation. This effect is due to the medication's mechanism of action in dilating blood vessels, which can result in lowered blood pressure. Monitoring for hypotension is crucial to prevent complications such as dizziness, lightheadedness, or fainting in clients taking enalapril.

Correct Answer: B

Rationale: Enalapril is an ACE inhibitor that works by dilating blood vessels and reducing blood pressure. Therefore, monitoring for hypotension is crucial as it can be a potential adverse effect of this medication. Hypertension, tachycardia, and hyperglycemia are not typically associated with enalapril use.