Use of a combination of lisinopril and hydrochlorothiazide in the treatment of arterial hypertension

Twenty-nine patients with uncomplicated essential hypertension were treated with a combination of 20 mg of lisinopril, a non-sulphydryl angiotensin-convertin enzyme inhibitor, and 12.5 mg of hydrochlorothiazide. After a two-week washout period, patients were randomly allocated to one of two groups. Group A received the trial drug in separate tablets, while group B received both drugs in a single tablet, over a six-week period. After that, dose was doubled if blood pressure had not been normalized. The groups were then crossed over. Laboratory tests for safety were carried out after washout and at six and 12 weeks of treatment. Unwanted effects were registered and graded as mild, moderate, or severe. Mean reductions in blood pressures were as follows: systolic pressure decreased 29 mmHg (17%) and 30 mmHg (18%) in weeks 6 and 12, respectively, in group A. In group B reductions were 21 mmHg (13%) and 33 mmHg (20%), respectively, at weeks 6 and 12 of treatment. Diastolic blood pressure was reduced 16 mmHg (15%) at weeks 6 and 12 in group A. Reductions of 18 mmHg (17%) and 20 mmHg (19%), respectively, were observed in the same stages in group B. The differences between these values and baseline were highly significant, but no statistically significant difference was observed in the intergroup comparison. Heart rate did not change. With both modalities of drug administration, a rate of 90% of diastolic blood pressure normalization was achieved. One patient dropped out due to severe cough. This symptom was the most common unwanted effect. Laboratory values did not change throughout the trial. It is concluded that the fixed combination of 20 mg of lisinopril and 12.5 mg of hydrochlorothiazide is useful and well tolerated in patients with uncomplicated mild or moderate arterial hypertension.