Antihypertensive and renal effects of tienilic acid.

Tienilic acid, a diuretic agent effective at the cortical diluting segment of the distal tubule, has been found to have equivalent antihypertensive action in a dose of 250 mg twice daily to hydrochlorothiazide in a dose of 50 mg twice daily. Tienilic acid reduced arterial pressure without diminishing renal plasma flow or endogenous creatinine clearance; moreover, it did so whilst achieving hypouricaemia through a uricosuric effect. Hypokalaemia was observed but corrected by supplemental potassium. A transient but reversible, slight elevation in serum creatinine concentration and significant hypertriglyceridaemia were also observed. In conclusion, tienilic acid seems to be a novel diuretic, well-suited for the patient with hypertension, particularly if there is coincidental gout or coexisting hyperuricaemia.