Fixed combination of benazepril and very low dose hydrochlorothiazide in the treatment of mild to moderate essential hypertension: evaluation by 24-hour non invasive ambulatory blood pressure monitoring.

A double-blind, crossover, placebo-controlled study was undertaken in order to assess the antihypertensive efficacy of a fixed combination of benazepril and hydrochlorothiazide in two different dosages by ambulatory blood pressure monitoring (ABPM). After a three-week placebo wash-out period, 18 patients with mild to moderate essential hypertension, all males, aged 41-60 years, were randomized to receive benazepril 5 mg + hydrochlorothiazide 6.25 mg, benazepril 10 mg + hydrochlorothiazide 12.5 mg or placebo, all given once daily for 4 weeks, according to a 3 crossover period, arranged in a 3 x 3 latin square design. Patients were checked after the wash-out period and every 4 weeks thereafter. At each visit, 24-hour ABPM was performed by a non-invasive device (Spacelabs 90202); causal BP (by mercury sphygmomanometer) and HR were also measured. Both dosages of the fixed combination were equally effective in reducing systolic and diastolic BP values throughout the 24-hour period as compared to the placebo. The antihypertensive effect of the drug could be observed to a similar extent both during the day and night and was still significant 24-hour post-dosing. In addition, the fixed combination did not affect the normal BP circadian variability.