INFLUENCE OF LISINOPRIL ON URINARY ELECTROLYTES EXCRETION AFTER FUROSEMIDE IN HEALTHY-SUBJECTS

It has been reported that the urinary excretions of chloride (Cl), pot assium (K), and magnesium (Mg), but not sodium (Na), after furosemide, a loop diuretic were decreased by pretreatment with lisinopril, an AC E inhibitor in hypertensive subjects. The electrolytes disturbance ind uced by furosemide might be ameliorated by lisinopril. The present re- examines this potential drug interaction in healthy subjects. Lisinopr il (20 mg) or its matching placebo was given orally using a double-bli nd, crossover design. Four hours after lisinopril administration, furo semide (20 mg) was injected intravenously and urine was collected duri ng the following intervals: 0-0.5, 0.5-1, 1-1.5, 1.5-2, 2-3, 3-4, and 4-6 hours, Blood samples for plasma furosemide concentration were obta ined at 0.51, 1, 1.5, 2, 3, 4, and 6 hours after the agent. There were no significant differences between the two trials in plasma concentra tions of furosemide or urinary excretions of the agent. Urine volume a nd urinary excretions of electrolytes (Na, Cl, k, and Mg) after the fu rosemide with lisinopril administration were not significantly differe nt from those of placebo at any observation period. These results sugg est that the urinary excretions of electrolytes after furosemide admin istration are not influenced by pretreatment with lisinopril.