Relation between dose of bendrofluazide, antihypertensive effect, and adverse biochemical effects.

OBJECTIVE--To determine the relevant dose of bendrofluazide for treating mild to moderate hypertension. DESIGN--Double blind parallel group trial of patients who were given placebo for six weeks and then randomly allocated to various doses of bendrofluazide (1.25, 2.5, 5, or 10 mg daily) or placebo for 12 weeks. SETTING--General practices in Zealand, Denmark. PATIENTS--257 Patients with newly diagnosed or previously treated hypertension, aged 25-70, who had a mean diastolic blood pressure of 100-120 mm Hg after receiving placebo for six weeks. MAIN OUTCOME MEASURES--Reduction in diastolic blood pressure and changes in biochemical variables (potassium, urate, glucose, fructosamine, total cholesterol, apolipoprotein A I, apolipoprotein B, and triglyceride concentrations). RESULTS--All doses of bendrofluazide significantly reduced diastolic blood pressure to the same degree (10-11 mm Hg). Clear relations between dose and effect were shown for potassium, urate, glucose, total cholesterol, and apolipoprotein B concentrations. The 1.25 mg dose increased only urate concentrations, whereas the 10 mg dose affected all the above biochemical variables. CONCLUSION--The relevant range of doses of bendrofluazide to treat mild to moderate hypertension is 1.25-2.5 mg a day. Higher doses caused more pronounced adverse biochemical effects including adverse lipid effects. Previous trials with bendrofluazide have used too high doses.