<prompt> Nephrogenic diabetes insipidus is caused by all of the following except: March 2008Toxicity of lithiumAmyloidosisHypocalcemiaHypokalemia  <response>: Ans. C: Hypocalcemia Nephrogenic diabetes insipidus is characterized by a decrease in the ability to concentrate urine due to a resistance to ADH action in the kidney. The 24 hour urine volume is more than 50 mLkg body weight and the osmolarity is less than 300 mosmol L. Nephrogenic diabetes insipidus can be observed in: Drugs: - Lithium toxicity - Demeclocycline - Methoxyflurane - Amphotericin B Metabolic Hypercalcemia, - Hypokalemia, iii. Infiltration: - Amyloidosis Tubulointerstitial diseas Rarely, diabetes insipidus may be hereditary 