Correct Answer: B

Rationale: The correct instruction for a client taking Acyclovir is to increase fluid intake during therapy. Acyclovir can cause nephrotoxicity, potentially leading to kidney damage. Increasing fluid intake helps prevent this adverse effect by promoting adequate renal function and drug elimination.

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: Propranolol exerts its pharmacological action by blocking stimulation of both beta1 and beta2 receptors. By doing so, it leads to decreased heart rate and blood pressure. Therefore, both options A and C are correct as propranolol affects both types of beta receptors.

Correct Answer: C

Rationale: Muscle pain should be reported immediately as it can indicate rhabdomyolysis, a severe adverse effect of atorvastatin. Rhabdomyolysis is characterized by muscle pain, weakness, and can lead to serious complications such as kidney damage, making it crucial for the nurse to notify the provider promptly.

Correct Answer: A

Rationale: Spironolactone is a potassium-sparing diuretic that can lead to hyperkalemia as an adverse effect. Hyperkalemia is characterized by elevated levels of potassium in the blood, which can be dangerous and lead to cardiac arrhythmias. Therefore, monitoring for signs and symptoms of hyperkalemia is crucial when a client is taking spironolactone.