Amphotericin B-induced nephrogenic diabetes insipidus in a case of cryptococcemia

A 66-year-old woman with malignant lymphoma became neutropenic during chemotherapy and developed cryptococcernia. After amphotericin B had been commenced, she developed significant hypokalemia and polyuria, though her renal function remained stable. The laboratory findings showed no evidence of renal tubular acidosis. With vigorous water and potassium replacement, amphotericin B had been continued until the cumulative dose reached 2.5 g. After the cessation of amphotericin B, the hypokalemia and polyuria resolved promptly. Based on theses findings, she was diagnosed as nephrogenic diabetes insipidus; with hypokalemia and without renal tubular acidosis due to amphotericin B. This complication is usually reversible, and vigorous water and potassium replacement may allow completion of treatment by ampbotericin B, though careful monitoring of body water balance and renal function is of importance.