Effect of indomethacin on clinical progress and renal function in cystinosis.

Abstract

Three children with nephropathic cystinosis were treated with indomethacin 3 mg/kg a day for 9-18 mo. The drug produced worthwhile clinical improvement in all, with marked beneficial effects on polyuria, polydipsia and general well-being. Clearance studies performed under conditions of maximal water diuresis showed that proximal tubular Na reabsorption was increased in all children, with consequent reduction in Na delivery to the distal nephron leading to reduced free water clearance and distal tubular cation exchange. Plasma Na and K concentrations became normal in all patients, with improvement in phosphate and bicarbonate concentrations in one. Renal function continued to deteriorate, but without obvious acceleration of the process by the drug. A beneficial effect on growth was not seen, but indomethacin is a useful adjunct to the symptomatic treatment of children with severe nephropathic cystinosis.