Low-dose bisoprolol/hydrochlorothiazide: an option in first-line, antihypertensive treatment

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)