AIM: To assess the effects of chronic evening oral administration of bromazepam alone or in combination with propranolol on ambulatory blood pressure (BP) and heart rate (HR) in mild hypertensive subjects.
METHODS: Thirty-seven mild hypertensive patients after a 2-week placebo period were randomized to bromazepam 3 mg, propranolol 40 mg, bromazepam 3 mg plus propranolol 40 mg or placebo for 2 weeks according to a double-blind, double dummy, cross-over design. After each treatment period, 24-h BP and HR ambulatory monitoring was performed by using a non-invasive device.
RESULTS: Ambulatory monitoring showed that during night-time SBP and DBP values were unaffected by bromazepam as compared to placebo, whereas SBP was significantly reduced by propranolol both when taken alone and in combination with bromazepam. HR nocturnal values were significantly reduced by propranolol, whereas they were significantly increased by bromazepan both when taken alone (+11.5%, p < 0.05 vs. placebo) and in combination with propranolol (+12.8%, p < 0.05 vs. propranolol). No significant difference in day-time values of SBP, DBP and HR was observed among the 4 treatment groups.
CONCLUSIONS: In mild hypertensive patients, evening consumption of bromazepam for a 2-week period did not affect BP, while it increased nocturnal HR. Such an increase was observed both when bromazepam was taken alone and in combination with propranolol, which suggests that it depends on a bromazepam mediated decrease in vagal tone. Whatever the mechanism, the HR nocturnal increase might be of clinical relevance, due to the role of high HR as cardiovascular risk factor, particularly in already at risk hypertensive subjects.