Medium-term effects of betaxolol monotherapy and combination therapy with nitrendipine on lipoprotein and apolipoprotein metabolism in patients with mild to moderate essential hypertension

The objective of this study was to assess the medium-term effects of betaxolol, a long-acting, lipid-soluble, cardioselective, beta-adrenergic antagonist, alone and in combination with nitrendipine on blood pressure (BP) and metabolism of lipid, lipoprotein and apolipoprotein in patients with mild to moderate hypertension. Forty-seven patients (21 men, 26 women, average age 54 years) participated in an open controlled clinical trial. After a 4-week washout period, all of the patients received betaxolol monotherapy at a dose of 5-10 mg daily for 6 months (Phase I). From month 7 through month 12 (Phase II), half of the total patients (Group B, n = 23) with diastolic blood pressure (DBP) of 95 mm Hg or more at the end of Phase I were also given nitrendipine (10-20 mg, once daily), while the remaining patients (Group A, n = 24) continued to receive only betaxolol. Systolic blood pressure (SBP), DBP, and heart rate (HR) were monitored once monthly. Serum lipid profiles were measured at study entry and after 6 and 12 months of therapy. Betaxolol significantly reduced SBP, DBP, and HR in both groups during Phase I, and the reductions in SBP and DBP were markedly less in Group B than in Group A. During Phase II, the additional reduction of SBP and DBP to levels similar to those in Group A was achieved by betaxolol in combination with nitrendipine, and HR was slightly but significantly increased. Betaxolol monotherapy reduced serum levels of high density lipoprotein cholesterol (HDL-C) and increased levels of triglyceride, apolipoprotein (apo) C-II and apo C-III. Combination therapy with betaxolol and nitrendipine increased serum apo A-I but did not affect other lipid profiles. Our results indicate that betaxolol is an effective antihypertensive drug which has a preferable effect on HR and HDL profiles when combined with nitrendipine.