Quinapril, hydrochlorothiazide, and combination in patients with moderate to severe hypertension

This 8-week, double-blind, multicentre study compared the efficacyand safety of the combination of quinapril and hydrochlorothiazide(HCTZ) with each drug as monotherapy. Outpatients with moderateto severe hypertension defined as supine diastolic blood pressure(DBF) 105 mmHg and 120 mmHg at the end of a 2 to 4-week placebo-baselineperiod were randomly assigned to one of the three treatments:once-daily 10 mg quinapril plus 12.5 mg HCTZ or monotherapywith these doses. After 4 weeks, the doses were to be doubledfor the remaining 4 weeks. Three hundred and sixty-eight patientswere randomized to double-blind medication; 346 completed thestudy. Seven patients withdrew due to lack of efficacy. Fourpatients withdrew due to side effects. In all three treatmentgroups, clinically significant reductions in DBP were achieved.Combination therapy was statistically more effective than eachcomponent taken as monotherapy. Adverse events were infrequentin all treatment groups. No patients experienced symptomatichypotension or orthostatic hypotension.