Nephrogenic diabetes insipidus is caused by all of the following except: March 2008: (A) Toxicity of lithium, (B) Amyloidosis, (C) Hypocalcemia, (D) Hypokalemia
Answer is C. 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 mL/kg 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