Correct Answer: B

Rationale: Atenolol is a beta-blocker that can cause bradycardia, leading to a decreased heart rate. Monitoring heart rate regularly is essential to detect any significant decreases promptly and seek medical attention. While other choices may be relevant to the client's overall health, monitoring heart rate is the priority instruction due to the nature of Atenolol's effects.

Correct Answer: A

Rationale: The correct answer is hyperkalemia. Spironolactone is a potassium-sparing diuretic that can lead to an increase in potassium levels. Hyperkalemia can be dangerous, causing muscle weakness and cardiac dysrhythmias, making it essential for the nurse to monitor potassium levels closely when a client is on Spironolactone.

Correct Answer: D

Rationale: Duloxetine is a serotonin-norepinephrine reuptake inhibitor commonly used to manage fibromyalgia. It helps in reducing pain and improving mood in individuals with this condition. Additionally, duloxetine is also utilized in treating depression and diabetic peripheral neuropathy.

Correct Answer: C

Rationale: The correct answer is C. Erythromycin should be taken on an empty stomach with a full glass of water to increase absorption. Taking it with milk (choice A) or an antacid (choice D) can interfere with its absorption. Avoiding direct sunlight (choice B) is not directly related to the administration of erythromycin.

Correct Answer: A

Rationale: Orthostatic hypotension is a known adverse effect of Phenelzine, a monoamine oxidase inhibitor (MAOI) used for depression. It is caused by a sudden drop in blood pressure when changing positions, leading to symptoms like dizziness or fainting. Monitoring for orthostatic hypotension is crucial during Phenelzine therapy to prevent complications.