Cis-platinum and distal renal tubule toxicity.

Glomerular filtration rate (GFR) and plasma electrolyte concentrations were evaluated prospectively in 22 consecutive patients treated with serial courses of cisplatinum combination chemotherapy. In addition, renal distal tubular function was assessed in the first 12 by measurement of overnight urinary concentration after intranasal desamino-d-arginine vasopressin inhalation and by a standard short urinary acidification test following the administration of oral ammonium chloride. Cumulative and dose-related hypomagnesaemia was observed in all patients but was unassociated with clinical symptoms. No significant fall in GFR was seen in the group as a whole but four of the 12 patients studied more comprehensively developed impairment of urinary concentrating and acidifying abilities, independent of any change in GFR. This indicates a selective effect on the renal distal tubule.