Correct Answer: C

Rationale: Hydrochlorothiazide is classified as a diuretic. Diuretics are medications that help the body get rid of excess salt and water by increasing urine production, reducing fluid retention, and lowering blood pressure.

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.

Correct Answer: B

Rationale: Creatinine levels should be monitored to evaluate vancomycin's effect on kidney function. Vancomycin can be nephrotoxic, so monitoring creatinine levels helps assess renal function and ensure that the medication is not causing harm to the kidneys.

Correct Answer: A

Rationale: Caffeine can increase the risk of theophylline toxicity as it competes for the same metabolic pathways, so clients should avoid consuming caffeine while on theophylline to prevent adverse effects.

Correct Answer: D

Rationale: The correct instruction for the client who has a new prescription for Levothyroxine to treat hypothyroidism is not to discontinue the medication without consulting the provider. Abrupt cessation could lead to the return of hypothyroid symptoms, emphasizing the importance of medical guidance when considering any changes to the treatment plan.