Which medication is a classic cause of nephrogenic diabetes insipidus?

Which medication is a classic cause of nephrogenic diabetes insipidus?

• A. Desmopressin
• B. Lithium
• C. Acetaminophen
• D. Furosemide

Answer: (B)

Nephrogenic diabetes insipidus happens when the kidney fails to respond to vasopressin, so water reabsorption in the collecting ducts is impaired and urine remains dilute despite dehydration. Lithium is a classic culprit because it enters collecting duct principal cells through ENaC channels and disrupts the vasopressin signaling pathway. It reduces the cAMP response and prevents proper trafficking of aquaporin-2 water channels to the apical membrane, so even with vasopressin present, the kidney cannot concentrate urine. Because the problem is renal insensitivity, giving desmopressin (a vasopressin analog) won’t adequately reduce urine output in nephrogenic DI, unlike in central DI where it is effective. The other agents listed do not cause this condition; acetaminophen has no effect on renal concentrating ability, and loop diuretics like furosemide are not classic causes of nephrogenic DI (though they can be used in management under certain circumstances).

Nephrogenic diabetes insipidus happens when the kidney fails to respond to vasopressin, so water reabsorption in the collecting ducts is impaired and urine remains dilute despite dehydration. Lithium is a classic culprit because it enters collecting duct principal cells through ENaC channels and disrupts the vasopressin signaling pathway. It reduces the cAMP response and prevents proper trafficking of aquaporin-2 water channels to the apical membrane, so even with vasopressin present, the kidney cannot concentrate urine.

Because the problem is renal insensitivity, giving desmopressin (a vasopressin analog) won’t adequately reduce urine output in nephrogenic DI, unlike in central DI where it is effective. The other agents listed do not cause this condition; acetaminophen has no effect on renal concentrating ability, and loop diuretics like furosemide are not classic causes of nephrogenic DI (though they can be used in management under certain circumstances).