A double-blind study of tienilic acid with two year follow-up of patients with mild to moderate essential hypertension.

In a double-blind study, thirty patients having mild to moderate essential hypertension were randomly assigned to a six week regimen of either tienilic acid, hydrochlorothiazide, or placebo. Blood pressure was significantly reduced with tienilic acid and hydrochlorothiazide although more so with tienilic acid. Serum uric acid declined strikingly with tienilic acid and increased significantly with hydrochlorothiazide. Serum potassium declined slightly with tienilic acid but more so with hydrochlorothiazide. Serum creatinine and blood urea nitrogen increased slightly more with tienilic acid than with hydrochlorothiazide. There were no clinical adverse effects to any of the medications during this study. Twenty-four months of continuous administration of tienilic acid revealed maintenance of blood pressure effect, but with slight increases in blood urea nitrogen, serum creatinine and uric acid and slight decreases in serum potassium as compared to six weeks administration. Tienilic acid appears to be a useful new antihypertensive agent. The hypouricaemic effect is profound and strongly suggests the need for continuing evaluation of this compound because of its unique combination of diuretic, antihypertensive and hypouricaemic properties.