[Hyperkalemia with potassium-sparing and potassium-losing diuretics. Results from the Comprehensive Hospital Drug Monitoring Bern (CHDM)].

Of 5047 in-patients in the Division of Internal Medicine, Zieglerspital Bern (regional/teaching hospital), admitted from 1982 to 1985, 2412 were treated with at least one diuretic. The hospital records of these patients were reviewed with regard in particular to serum potassium and creatinine values as well as potassium supplementation. On the basis of this evaluation the patients were assigned to 6 different treatment groups and the relative occurrence rate of hyperkalemia probably related to drug treatment was determined. Of the 590 patients treated with only potassium losing diuretics, none was found to show a hyperkalemia event; of the 742 patients on potassium losing diuretics and potassium supplementation, 27 (3.6%) developed hyperkalemia. In the 439 patients under combined diuretics (potassium sparing with potassium losing) without potassium substitution, 76 (17.3%), and in the 381 under combined diuretics with potassium substitution 24 (6.3%), developed hyperkalemia. The further groups of patients are also described. Renal function was estimated by the formula of Cockcroft and Gault. Reduced renal function is a significant risk-factor for hyperkalemic events under combined diuretics. All hyperkalemic events were within a serum potassium range of 5.1-7.0 mmol/l.