Correct Answer: A

Rationale: Weight gain is a common adverse effect of long-term prednisone use.

Correct Answer: D

Rationale: Leucovorin, a folic acid derivative and an antagonist to Methotrexate, is given within 12 hours of high doses of Methotrexate to protect healthy cells from the toxic effects of Methotrexate. It helps to reduce the bone marrow suppression and gastrointestinal side effects caused by Methotrexate, supporting the client's overall well-being during chemotherapy treatment.

Correct Answer: D

Rationale: Dizziness and decreased libido are common adverse effects of Venlafaxine. Cough and alopecia are not typical side effects of this medication.

Correct Answer: B

Rationale: Grapefruit juice can inhibit the metabolism of amlodipine, a calcium channel blocker, leading to increased drug levels in the blood. This can result in potentiated side effects and potential toxicity. Therefore, it is important for the client to avoid grapefruit juice while taking amlodipine.

Correct Answer: A

Rationale: The correct statement for the nurse to include when teaching a client prescribed Omeprazole is to take the medication before meals. Omeprazole, a proton pump inhibitor, is most effective when taken before meals as it works by reducing the amount of acid produced in the stomach.