Acute effect of high dose (48 mg) of piretanide in advanced renal insufficiency.

1 The acute effects of a high dose of piretanide, a new potent diuretic were studied in eight patients with severely impaired renal function (GFR between 0.09 and 0.17 ml s-1 1.73 m-2). 2 After hydration and following two control periods, a single dose of 48 mg piretanide was ingested. Thereafter, urine was collected every 30 min for 2 h and every hour for the next 4 h. Urinary fluid losses were replaced orally (100 ml of water ever hour) and intravenously (isotonic saline + glucose infusion). 3 The following measurements were made: urine flow rate, clearances of inulin, PAH, urea, creatinine, uric acid, osmolar and free water clearances, excretion rates of sodium, chloride, potassium, calcium, phosphate, bicarbonate, ammonium, titratable acidity and urine pH. 4 Piretanide (48 mg) appeared to be effective in advanced renal insufficiency, producing a significant increase in urine flow rate, in sodium, chloride, potassium and calcium excretion and in Cosm. 5 There was no significant change in GFR, as measured by inulin clearance, or in the other measured parameters.