Long-term usage of tienilic acid in essential hypertension.

The purpose of this double-blind study was to compare the effects on blood pressure of tienilic acid and hydrochlorothiazide in patients with essential hypertension. The biochemical effects of tienilic acid in relation to those of hydrochlorothiazide were also determined over a long-term period of therapy. Sixty-six outpatients with mild to moderate essential hypertension were treated for seven months with either 250 mg of tienilic acid or 50 mg of hydrochlorothiazide after a 3 week placebo period. When warranted, dosage was increased to a maximum of 500 mg of tienilic acid and 100 mg of hydrochlorothiazide daily. Results indicate that tienilic acid reduced blood pressure significantly and to the same extent as hydrochlorothiazide. No significant side effects were observed. The effects on potassium, blood urea nitrogen and creatinine were comparable in both groups. However, serum uric acid rose with hydrochlorothiazide but fell with tienilic acid. In view of this effect, tienilic acid may have certain advantages over thiazide therapy in the treatment of hypertension.