Correct Answer: A

Rationale: Grapefruit juice should be avoided when taking Atorvastatin because it can increase the blood levels of the medication, potentially leading to a higher risk of adverse effects like muscle pain and liver damage. It is important to follow this instruction to ensure the safe and effective use of Atorvastatin.

Correct Answer: A

Rationale: In this situation, where the client's blood pressure is significantly lowered due to Verapamil administration, the nurse should anticipate a prescription for Calcium gluconate. Calcium gluconate is used to reverse severe hypotension caused by Verapamil. It should be given slowly intravenously as it counteracts the vasodilation caused by Verapamil, helping to normalize blood pressure levels.

Correct Answer: C

Rationale: In a client receiving Magnesium Sulfate IV for Preeclampsia, a urinary output less than 25 to 30 mL/hr indicates magnesium sulfate toxicity and should be reported to the provider for further evaluation and management.

Correct Answer: A

Rationale: The correct answer is St. John's wort. St. John's wort can reduce the effectiveness of Warfarin by interacting with its metabolism, potentially leading to decreased anticoagulant effects. Therefore, the nurse should instruct the client to avoid using St. John's wort while taking Warfarin to prevent adverse drug interactions. Additionally, it is essential to educate the client about other herbal supplements like garlic and ginseng, which may also interact with Warfarin and should be avoided to ensure the medication's efficacy and safety.

Correct Answer: C

Rationale: Propranolol is a beta-adrenergic antagonist that decreases heart rate and controls tremors.