RESUMO
Nephrogenic diabetes insipidus is a condition characterized by polyuria with dilute urine due to the inability of the principal cells of the renal collecting ducts to respond to antidiuretic hormone and concentrate urine. Nephrogenic diabetes insipidus can be drug induced, and several chemotherapeutic agents have been reported to cause it. Bendamustine is a traditional chemotherapeutic agent being studied for treatment for relapsed systemic AL amyloidosis. We report a case of a 59-year-old man with AL amyloidosis who developed partial nephrogenic diabetes insipidus after receiving bendamustine for treatment of AL amyloidosis. The nephrogenic diabetes insipidus responded well to sodium restriction, hydrochlorothiazide, and desmopressin treatment, allowing the patient to receive subsequent bendamustine cycles without polyuria. Nephrogenic diabetes insipidus resolved shortly after completion of bendamustine therapy.