A client is diagnosed with central diabetes insipidus related to decreased antidiuretic hormone (ADH) secretion. Which medication should the nurse anticipate administering?

Desmopressin is a synthetic analogue of arginine vasopressin that exhibits high selectivity for V2 receptors in renal collecting ducts. By upregulating aquaporin-2 channels, the drug restores normal water reabsorption, concentrating urine and expanding intravascular volume. This target action effectively reverses the profound polyuria and systemic dehydration characterizing central diabetes insipidus. A. Desmopressin (DDAVP): This exogenous hormone replacement replaces the missing endogenous antidiuretic hormone, correcting the underlying pathophysiological deficit. It rapidly reduces free water wasting, lowers serum osmolality, and stabilizes fluid balances. It represents the gold-standard therapy for central diabetes insipidus. B. Furosemide: This loop diuretic inhibits sodium-potassium-chloride cotransporters in the thick ascending limb, intentionally forcing massive fluid and solute excretion. Administering this agent would worsen intravascular volume depletion and hypernatremia. It is completely contraindicated in water-wasting conditions. C. Insulin: This pancreatic hormone facilitates cellular glucose uptake and glycogen synthesis, serving as the primary treatment for diabetic ketoacidosis. It has no structural or functional interaction with renal aquaporin channels or vasopressin receptors. It cannot resolve a diabetes insipidus water imbalance. D. Metformin: This biguanide decreases hepatic gluconeogenesis and improves peripheral insulin sensitivity in patients with type 2 diabetes mellitus. It does not possess antidiuretic properties or influence the posterior pituitary-renal axis. It plays no role in treating water homeostasis disorders.