Effects of Oral Administration of Alprazolam and Lorazepam as Hypnotics on Cardiovascular Parameters in Hypertensive Patients

BACKGROUND: Previous studies have suggested that evening intake of benzodiazepine affects blood pressure (BP) and/or heart rate (HR) in healthy and hypertensive subjects. The aim of this study was to compare the effect of chronic oral administration of alprazolam and lorazepam as hypnotics on ambulatory BP and HR in patients with mild hypertension.

METHODS: Consecutive outpatients of both sexes with newly diagnosed, never-treated mild hypertension were randomized, after a 4-week placebo run-in period, to receive alprazolam 0.5 mg plus placebo, lorazepam 1 mg plus placebo, or placebo plus placebo for 2 weeks in 3 crossover periods, each separated by a 1-week placebo wash-out period. At the end of the initial placebo run-in and of each treatment period, 24-hour ambulatory BP and HR monitoring was performed using a noninvasive device.

RESULTS: In the 32 patients, no treatment had any effect on 24-hour and daytime systolic BP (SBP), diastolic BP (DBP), and HR, which remained unchanged. During the nighttime, SBP and DBP values were unaffected by alprazolam, as compared with placebo, whereas DBP was significantly higher after treatment with lorazepam (+3.7%, P < 0.05 vs placebo). Nocturnal HR mean values were significantly increased by lorazepam (+10.1%, P < 0.01 vs placebo), whereas they did not change after alprazolam.

CONCLUSIONS: In patients with mild hypertension, oral intake of alprazolam or lorazepam as hypnotics did not affect ambulatory BP or HR values. A slight increase in nighttime DBP was observed with lorazepam, whereas alprazolam showed no effect on nocturnal BP and HR, probably reflecting a stimulating effect of the drug on central α2-receptors.