WEDNESDAY, July 16, 2025 (HealthDay News) -- Bedtime dosing with antihypertensive medication yields better nocturnal blood pressure control and improved circadian rhythm, according to a study published online July 9 in JAMA Network Open.Runyu Ye, Ph.D., from Sichuan University in Chengdu, China, and colleagues compared the effects of morning versus bedtime antihypertensive medication administration on nocturnal blood pressure reduction and circadian rhythm in a randomized trial conducted at 15 hospitals involving patients with hypertension. Patients without prior antihypertensive treatment or who had discontinued antihypertensive agents for two weeks were randomly assigned to the morning (6 a.m. to 10 a.m.) or bedtime (6 p.m. to 10 p.m.) dosing groups (352 and 368, respectively); all patients received a single pill containing olmesartan (20 mg) and amlodipine (5 mg) daily for 12 weeks.The researchers found that patients in the bedtime dosing group showed significantly greater reductions in nighttime systolic blood pressure and nighttime diastolic blood pressure compared with patients in the morning dosing group (between-group differences, −3.0 and −1.4 mm Hg); better nocturnal systolic blood pressure control was seen (79.0 versus 69.8 percent) and circadian rhythm was improved. There was no difference in the incidence of nocturnal hypotension."These findings support the potential advantages of bedtime administration and offer new evidence to guide future research on antihypertensive chronotherapy," the authors write.Abstract/Full Text.Sign up for our weekly HealthDay newsletter