Double-blind assessment of tienilic acid in essential hypertension

The antihypertensive effectiveness of tienilic acid in doses of 250 mg once and twice daily was compared to hydrochlorothiazide 50 mg once and twice per day in a randomized double-blind trial lasting six weeks. Blood pressure fell significantly and to a similar extent with the larger dose of both drugs. This was accompanied by a slight decrease in body weight and serum potassium concentration and a slight increase in serum creatinine and blood urea nitrogen. The magnitude of these changes was similar with both drugs. Unlike hydrochlorothiazide, however, the administration of tienilic acid was associated with a marked drop in the concentration of serum uric acid. No disturbing side effects or evidence of serious toxicity were noted during treatment with the new drug.