Correct Answer: A

Rationale: The therapeutic effect of lithium is that it prevents or decreases the incidence of acute manic episodes in patients with bipolar disorder. Lithium is commonly used as a mood stabilizer in the treatment of bipolar disorder due to its ability to reduce the frequency and severity of manic episodes.

Correct Answer: B

Rationale: Abruptly stopping prednisone can result in adrenocortical insufficiency due to suppression of the adrenal glands. Gradually tapering the dose helps the body to adjust and resume its natural cortisol production, preventing adrenal insufficiency.

Correct Answer: C

Rationale: The correct instruction for a client prescribed Alendronate is to sit upright for at least 30 minutes after taking the medication. Alendronate can cause esophageal irritation, and maintaining an upright position helps prevent this adverse effect by reducing the risk of reflux of the medication into the esophagus.

Correct Answer: D

Rationale: Metformin's primary pharmacological action is to decrease hepatic glucose production. By reducing hepatic glucose production, metformin helps to lower blood sugar levels and improve insulin sensitivity in the liver.

Correct Answer: A

Rationale: Spironolactone, a potassium-sparing diuretic, can lead to hyperkalemia due to its mechanism of action. Hyperkalemia, or elevated potassium levels, can result in serious cardiac complications and requires immediate medical attention. Therefore, the nurse should promptly report any signs or symptoms of hyperkalemia to prevent potential adverse outcomes in the patient.