Two recent, multicenter, double-blind, placebo-controlled studies established the efficacy and safety of low-dose
bisoprolol/hydrochlorothiazide (
HCTZ) in patients with mild to moderate
essential hypertension.
Bisoprolol, a cardioselective beta-blocker, was used in a dose of 2.5 mg, 5 mg, or 10 mg.
HCTZ was used at a dose of 6.25 mg. This low-dose compound was developed to minimize dose-related adverse effects. The addition of
HCTZ to each of the doses of
bisoprolol was compared with monotherapy and placebo. Results of both studies demonstrated that this once-a-day, low-dose option effectively reduced sitting diastolic and systolic blood pressure measured at the end of the 24-hour dosing period.
Drug-related adverse effects, including those generally associated with traditional beta-blocker
therapy, were infrequent in individuals who received the low-dose
bisoprolol/
HCTZ regimen. Dose-related side effects were minimized because of the low doses of the two agents used together. There were no significant changes in mean total
cholesterol,
triglycerides, or serum
glucose with
bisoprolol/
HCTZ 6.25 mg
therapy versus placebo (analysis of variance statistical methods). The incidence of treatment-induced
hypokalemia with
bisoprolol/
HCTZ 6.25 mg was not significant;
uric acid elevations were minimized, and the incidence of
hyperuricemia was significantly (P < 0.01) less with
bisoprolol/
HCTZ 6.25 mg than with 25 mg of
HCTZ. Once-a-day dosing with the low-dose agent controlled (defined as a sitting diastolic blood pressure < or = 90 mmHg and/or a decrease from baseline > or = 10 mmHg) blood pressure in up to 80% of patients for a full 24 hours after dosing.(ABSTRACT TRUNCATED AT 250 WORDS)