Which of the drugs most likely triggered the patient's anuria?

Correct Answer: C

Rationale: Hydrochlorothiazide is a diuretic that can lead to electrolyte imbalances and kidney issues, including anuria (inability to urinate). It is important to monitor patients on hydrochlorothiazide for signs of kidney dysfunction, especially in those with a history of hypertension and other comorbid conditions.

Correct Answer: A

Rationale: The appropriate drug for the patient at this time would be Amitriptyline. The patient, who was previously discharged on valproic acid for bipolar disorder, is now experiencing depressive symptoms after discontinuing therapy. Amitriptyline, a tricyclic antidepressant, would be suitable for treating the patient's depression. Tricyclic antidepressants like Amitriptyline are commonly used in the treatment of mood disorders, including bipolar depression. Therefore, choice A is the correct answer.

Correct Answer: C

Rationale: Amiloride is a potassium-sparing diuretic that can help reduce excessive urination and fluid intake in patients with symptoms of diabetes insipidus. It works by affecting the reabsorption of sodium and water in the kidneys, helping to balance fluid levels and decrease urinary output. Furosemide, hydrochlorothiazide, spironolactone, and conivaptan are not typically used to treat the specific symptoms described in the case.

Correct Answer: B

Rationale: Norepinephrine is a neurotransmitter that plays a role in regulating blood pressure. Drugs that increase norepinephrine levels can lead to elevated blood pressure, as seen in this patient. Atomoxetine, phenylephrine, guanfacine, and clonidine do not directly affect norepinephrine levels in a way that would cause high blood pressure.

Correct Answer: D

Rationale: The lateral hypothalamus is known to be involved in the regulation of hunger and satiety. Amphetamines, which act by increasing catecholamine release in the central nervous system, can suppress appetite by affecting the lateral hypothalamus. This region plays a key role in regulating feeding behavior and energy balance, making it a likely site of anorectic action for drugs like amphetamines.