Efficacy of cilazapril compared with hydrochlorothiazide in the treatment of mild-to-moderate essential hypertension. Multicentre Study Group.

The effect of cilazapril, a new inhibitor of angiotensin-converting enzyme, in a dosage of 2.5 or 5 mg once daily, was compared with that of hydrochlorothiazide 25 or 50 mg in 169 patients with mild to moderate hypertension. Blood pressure at entry was 158/103 mm Hg (cilazapril) and 160/103 mm Hg (hydrochlorothiazide). Cilazapril 2.5 mg caused a decrease in blood pressure of 14.7 +/- 2.3/12.6 +/- 1.2 mm Hg compared with a decrease of 12.6 +/- 2.2/10.2 +/- 1.2 mm Hg with hydrochlorothiazide 25 mg. Those patients who required an increase of dosage to the higher level then showed decreases of 15.0 +/- 2.1/14.3 +/- 1.2 (cilazapril) and 19.7 +/- 1.9/13.3 +/- 1.2 hydrochlorothiazide. All decreases in blood pressure were statistically significant but were not statistically different from each other. Fifty-one percent of patients reached a sitting diastolic blood pressure of 90 mm Hg or less receiving 2.5 mg of cilazapril and an additional 28 percent of patients reached this goal receiving 5 mg. The figures for patients receiving hydrochlorothiazide were comparable: 36 and 35 percent. Twenty-one adverse events remotely, possibly, or probably related to therapy were reported with cilazapril and 32 with hydrochlorothiazide. Three patients withdrew from cilazapril because of mild angioedema, headaches, and chest pain, respectively, and three patients withdrew from hydrochlorothiazide treatment because of fatigue, dizziness, and gastric hemorrhage. Hydrochlorothiazide caused a decrease in potassium levels and an increase in levels of cholesterol, uric acid, urea and - gamma cilazapril had no adverse biochemical effects. Cilazapril lowered blood pressure to the same extent as hydrochlorothiazide. Young patients had better responses to cilazapril than to hydrochlorothiazide. It is concluded that cilazapril is an effective and safe drug for patients with mild to moderate hypertension.