[Combined fixed doses therapy in systemic hypertension]

A single blind clinical trial was conducted to assess the concept that initial treatment in stage I and II of hypertension with fixed doses of two antihypertensives that have different modes of action and additive effects, in a 24-week period with bisoprolol (B), an cardioselective beta blocker, that does not have intrinsic sympathomimetic activity, associated to hydrochlorothiazide (HCTZ).

Thirty-one patients (22 females and 9 male) were included, with an age range between 20 and to 70 years (mean 52.45 +/- 12.10). After a two-weeks wash out period and a similar placebo phase, patients were assigned to receive a once-daily dosing of B 5 mg and 6.25 mg of HCTZ, during eight-weeks. Those patients that did not reduce their blood pressure below 90 mm Hg received a double dose of the beta blocker until the end of the study.

After twenty-fourth weeks period of the study, the mean systolic/diastolic blood pressures reduction was 23.9/20.1 mm Hg, compared to basal levels (p < 0.001). The adverse effects were rare. No clinically significant changes from baseline in laboratory parameters were observed.

This study demonstrates that fixed doses combination therapy with B/HCTZ (5 mg plus 6.25 mg) is effective and well tolerated, with a sustained hypotensive effect. Combined therapy with fixed doses, is an alternative in the initial treatment of mild to moderate hypertension.