by Justin Jackson, Phys.org
Research led by Sichuan University in China has revealed that bedtime antihypertensive medication dosing improves nocturnal blood pressure control over morning dosing in patients with hypertension.
Hypertension is a major global health challenge. In China, nearly 300 million individuals live with elevated blood pressure and fewer than 17% achieve adequate control. Nocturnal pressure is often the most difficult to manage and can be a better predictor of heart attack and stroke than daytime readings.
Previous studies have examined the optimal timing for antihypertensive medication with conflicting evidence and substantial variability in study outcomes.
In the study, “Morning vs. Bedtime Dosing and Nocturnal Blood Pressure Reduction in Patients With Hypertension: The OMAN Randomized Clinical Trial,” published in JAMA Network Open, researchers conducted a randomized clinical trial to compare bedtime versus morning administration of antihypertensive drugs on nocturnal blood pressure reduction and circadian rhythm control.
Across 15 hospitals in China, the trial enrolled 720 participants aged 18 to 75 years who either had never received antihypertensive treatment or had discontinued treatment for at least two weeks.
Participants were randomly assigned to groups receiving antihypertensive medication either in the morning (6:00–10:00 AM) or at bedtime (6:00–10:00 PM). All patients received a single-pill combination of olmesartan (20 mg) and amlodipine (5 mg), with dosage adjustments based on ambulatory and office blood pressure monitoring every four weeks.
After 12 weeks, the bedtime dosing group showed a greater reduction in nighttime systolic blood pressure, with a between-group difference of -3.0 mm Hg (95% CI, -5.1 to -1.0 mm Hg). Nighttime diastolic blood pressure also decreased more in the bedtime dosing group (-1.4 mm Hg; 95% CI, -2.8 to -0.1 mm Hg).
Nighttime systolic blood pressure control rates were higher with bedtime dosing (79.0%) compared with morning dosing (69.8%). Office systolic blood pressure control rates were 88.7% in the bedtime group and 82.2% in the morning group.
Bedtime dosing also lowered morning systolic and diastolic blood pressure with fewer dose escalations. No significant differences were observed in the incidence of nocturnal hypotension or reported adverse effects between groups.
Researchers conclude that bedtime dosing provided better nocturnal blood pressure control and improved circadian rhythm without reducing the efficacy of mean daytime or 24-hour blood pressure or increasing the risk of nocturnal hypotension.
These findings support the potential advantages of bedtime administration and offer evidence to guide future research on antihypertensive
Written for you by our author Justin Jackson, edited by Sadie Harley, and fact-checked and reviewed by Andrew Zinin—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You’ll get an ad-free account as a thank-you.
More information: Runyu Ye et al, Morning vs Bedtime Dosing and Nocturnal Blood Pressure Reduction in Patients With Hypertension, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.
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