2017 Volume 30 Issue 2 Pages 148-152
A 15-year-old boy presented to our clinic with nycturia since a month. He had been diagnosed with steroid-dependent nephrotic syndrome at the age of 3 years and was since then being treated with oral prednisolone, cyclosporin (CsA), and azathioprine. A nocturnal urine concentration test was performed, which showed a urinary concentration disorder, with increased plasma arginine vasopressin. These findings indicated partial nephrogenic diabetes insipidus (NDI).
These were suspected to be the effects of CsA, the dose of which had been increased from the time the treatment began to his current age; hence, the CsA dose was reduced back to the initial dose. Following this, the symptoms disappeared immediately. CsA is used for immunosuppression in nephrotic syndrome. Its use has been associated with acute and chronic nephrotoxicity. CsA is also known to cause urinary concentration disorder and its mechanism has been recently reported to involve its relationship with aquaporin2. Pediatric nephrologists who frequently use CsA should understand that CsA is involved in water homeostasis. Drug-induced NDI is rare in children. NDI should be considered as a possibility in cases of nephrotic syndrome, especially in those who are on CsA therapy. Thus, we report a case of a 15-year-old boy with drug induced NDI during treatment of nephrotic syndrome.
