Correct Answer: B

Rationale: The correct instruction for a client with a new prescription for Simvastatin is to avoid drinking grapefruit juice. Grapefruit juice can inhibit the metabolism of Simvastatin, leading to increased blood levels of the drug and a higher risk of adverse effects such as muscle pain and liver damage. It is important to educate the client about this potential interaction to ensure the safe and effective use of the medication.

Correct Answer: A

Rationale: The correct instruction for a client prescribed furosemide is to take the medication in the morning. Furosemide, a diuretic, is best taken in the morning to prevent nocturia, which is excessive urination at night. Taking it earlier in the day can help reduce disruptions to sleep patterns. Therefore, advising the client to take furosemide in the morning is crucial for optimal therapeutic effects.

Correct Answer: D

Rationale: Enoxaparin is a medication that should be administered as a subcutaneous injection in the abdomen to prevent bleeding complications. Massaging the injection site after administration should be avoided to reduce the risk of local irritation or bleeding. Rotating injection sites between the arms and thighs is a good practice for some medications but not recommended for Enoxaparin, which should be consistently given in the abdomen for optimal absorption and to avoid complications.

Correct Answer: A

Rationale: St. John's wort can reduce the effectiveness of Warfarin by interacting with its metabolism pathways, potentially leading to decreased anticoagulant effects. Therefore, clients on Warfarin therapy should avoid St. John's wort. While echinacea, garlic, and ginseng are also herbal supplements that can interact with Warfarin, St. John's wort is particularly known for its significant impact on Warfarin metabolism.

Correct Answer: D

Rationale: Anorexia, blurred vision, stomach pain, and diarrhea are common manifestations of digoxin toxicity. Patients should be advised to report these symptoms promptly to their healthcare provider for further evaluation and management.