Benazepril versus felodipine as supplement to bendroflumethiazide: evaluation by office and ambulatory blood pressure.

OBJECTIVE: To compare a combination of a thiazide diuretic and an angiotensin converting enzyme inhibitor with a thiazide diuretic and a calcium antagonist. DESIGN: A double-blind randomized trial with subjects in two parallel groups administered either 10-20 mg benazepril once daily or 5-10 mg extended-release felodipine once daily, both titrated according to diastolic office blood pressure. During run-in and all 12 weeks of the study members of both groups were administered 2.5 mg bendroflumethiazide once daily. We measured 24 h ambulatory blood pressure with thiazide alone and after 12 weeks of combination therapy. SETTING: General practices. PATIENTS: We studied 96 hypertensive patients (50 women and 46 men), aged 25-75 years, whose blood pressures were insufficiently regulated (i.e. office diastolic blood pressure >/= 95 mmHg) despite treatment with a thiazide diuretic for at least 3 months. RESULTS: The responses of office blood pressure after 12 weeks of treatment did not differ between the groups and neither did the proportions of responders. The ambulatory recordings revealed, after 12 weeks of treatment, a fall in daytime blood pressure of 16.3/10.3 mmHg in members of the benazepril group compared with a fall of 8.5/5.2 mmHg in members of the felodipine group (P < 0.001/<0.001). Analysis of variance showed that the systolic but not the diastolic office blood pressure in members of the benazepril group was significantly lower during the 12-week study period. When evaluating rising single quote, left (low)white-coat-positive' patients separately, there was a tendency for there to be a more pronounced reduction of their (normal) blood pressure with benazepril therapy. There was a significant reduction in weight of patients in the benazepril group (by 0.9 kg), but not of patients in the felodipine group. We observed no difference in side effects between the two treatment groups.CONCLUSION: Add-on therapies both with benazepril and with felodipine are effective and both drug regimens are well tolerated, but ambulatory blood pressure monitoring yielded differing results.