Effects of two doses of the fixed-combination chlorthalidone and slow-release metoprolol on blood pressure at rest and during exercise: a multicenter study.

To assess the efficacy and tolerability of two doses of chlorthalidone (CHL) and slow-release (SR) metoprolol (MET) given in fixed combination (standard dose: CHL 25 mg and MET 200 mg; lower dose: CHL 12.5 mg and MET 100 mg), a multicenter (5 Centers), double-blind, between-patients study was planned. Seventy-three mild to moderate hypertensive patients, 45 males and 28 females, aged 25-68 years (mean 51.4), at WHO stage I or II, were enrolled into the study. After a 2-week placebo wash-out period, eligible patients were randomly given either of the two drugs for six weeks: 33 were given the standard dose and 40 the lower one. Every 2 weeks, in the morning and 24 h after-dosing lying and standing systolic (SBP), diastolic blood pressure (DBP) and heart rate (HR) were recorded at rest. At the end of the placebo period and at the end of the study 24 h after-dosing a sub-maximal bicycle ergometer exercise test was performed. In comparison with placebo, both doses induced a significance decrease (p less than 0.01) in lying and standing SBP, DBP and HR, as well as in peak-exercise SBP, HR and pressure-rate product. Furthermore, a significant difference (p less than 0.05) of the higher dose versus the lower one was also observed at the end of the study in the above-mentioned parameters except for SBP at rest and at peak exercise and standing HR at rest.(ABSTRACT TRUNCATED AT 250 WORDS)