The effect of repeated
Azosemide infusions (20 mg in 500 ml 5%
glucose for one h) on urine volume and
electrolyte excretion, and on the activity of the renin-angiotensin-aldosterone system (RAAS) was studied in a group of 15 patients with benign
essential hypertension before and during treatment with the
beta-adrenergic blocker Trimepranol.
Azosemide alone had a marked but short-lasting
diuretic and
natriuretic effect. Repeated administration on three consecutive days led, however, to a progressive decrease in the natriuretic effectiveness of
Azosemide, associated with an increase in plasma
renin activity (from 0.413 o.032 to 1.631 0.438 pmol/l). Treatment with
Trimepranol 20 mg/day enhanced and prolonged the
diuretic and natriuretic response to
Azosemide concomitantly with a reduction of its stimulatory effect of RAAS. There results suggest that stimulation of the RAAS might be responsible for the diminishing effectiveness of repeated
Azosemide infusions and that the stimulation could be, at least partly, inhibited by a beta-blocker
Trimepranol, resulting in a greater
diuretic and
natriuretic effect of
Azosemide.