Activity of a new high efficiency diuretic in man: piretanide (HOE 118).

1 The pharmacological actions of piretanide, a new high efficiency diuretic, were studied in sixteen patients with GFR (inulin clearance) varying from 0.1–2.5 ml/s. 2 After hydration and following two control periods, a single dose of 6 mg piretanide was ingested. Thereafter, urine was collected every 30 min for 2 h and every hour for the next 4 h. Fluid losses were replaced. 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 Main results showed piretanide was efficient in the group with normal GFR (inulin clearance greater than 1.5 ml/s) and in the group with slightly decreased GFR (1.0 less than inulin clearance less than 1.4 ml/s), in terms of diuresis, natriuresis, kaliuresis and calciuresis. It was inefficient in the group with severe renal insufficiency (inulin clearance less than 0.3 ml/s). 5 Free water clearance showed preservation of diluting ability to a large extent. 6 In the three groups, no significant change in inulin clearance and PAH clearance occurred.