SERUM ELECTROLYTE CHANGES DURING LONG‐TERM TREATMENT WITH AMILORIDE HYDROCHLORIDE (MK‐870)

Twenty-two patients with severe heart disease treated with sulfamyl diuretics were given amiloride hydrochloride (MK-870) over periods of six weeks to 14 months. The potassium sparing effect of MK-870 was sufficient in all but one patient. No dangerous hyperkalemia was noted. There was a transitory decrease in the mean serum sodium concentration. The initial high mean serum CO2 level was decreased during the first six weeks but not during prolonged treatment. The initial low mean chloride level was increased. The increase was statistically significant after six weeks but not during prolonged treatment. Rises in serum creatinine levels were noted in two patients, one of whom had decreased renal function but the mean creatinine level was not significantly altered. The drug had no consistent effect on the serum uric acid level.