Diazepam as an oral hypnotic increases nocturnal blood pressure in the elderly

Background: No study has evaluated the cardiovascular effects of diazepam in elderly subjects that assume diazepam to induce sleep. Purpose: The present study was carried out in order to evaluate the effects of chronic administration of diazepam as hypnotic drug on blood pressure (BP) and heart rate (HR) in healthy elderly subjects. Patients and methods: Healthy, elderly subjects, aged 65–74 years, were treated with diazepam 5 mg or placebo—both administered once a day in the evening—for 4 weeks in two cross-over periods, each separated by a 2-week placebo period, according to a randomized, double-blind, cross-over design. At the end of each study period, clinical as well as 24-h ambulatory BP and HR were evaluated. Results: A total of 25 subjects were included in the analysis. At the end of a 4-week diazepam treatment, clinical as well 24-h BP and HR mean values were not significantly affected. Analysis of sub-periods showed that during night-time, systolic BP (SBP) values under diazepam were 7.6% higher than under placebo, with a mean difference of 7.9 mmHg (p < 0.01), diastolic BP (DBP) values were 5.8% higher, with a mean difference of 3.7 mmHg (p < 0.05 vs placebo) and HR values were 6.6% higher with a mean difference of 4.2 b/min (p < 0.05). The HR increase observed with diazepam persisted during the morning hours, whereas during the afternoon and evening hours SBP, DBP and HR values were similar in the two treatment groups. Conclusions: In elderly subjects chronic assumption of diazepam as hypnotic agent produced an increase in BP, in particular SBP, during night-time and of HR during night-time and morning hours. These effects, which probably depend on a diazepam-mediated increase in sympathetic drive and decrease in vagal tone, might be of clinical relevance due to the role of increased BP and HR as independent predictors of cardiovascular morbidity and mortality.