Bedtime Antihypertensive Medication Improves Blood Pressure Control

In a landmark study conducted by Sichuan University in China, researchers have determined that administering antihypertensive medication at bedtime significantly enhances blood pressure control during both nocturnal and daytime periods compared to morning dosing. The findings, published in the Journal of the American Medical Association (JAMA) Network Open on July 14, 2025, address a critical health concern as hypertension affects nearly 300 million individuals in China alone, with only 17% achieving adequate blood pressure control.

This randomized clinical trial, known as the OMAN trial, involved 720 participants aged between 18 and 75 years, who were either naïve to antihypertensive treatment or had stopped their medication for at least two weeks. Participants were randomly assigned to receive a single-pill combination of olmesartan (20 mg) and amlodipine (5 mg) either in the morning (between 6:00 AM and 10:00 AM) or at bedtime (between 6:00 PM and 10:00 PM). The study's primary objective was to evaluate the effects of timing on nocturnal blood pressure control and circadian rhythm regulation.

After a 12-week period, results indicated that the bedtime dosing group experienced a more substantial reduction in nighttime systolic blood pressure, with a mean decrease of 3.0 mm Hg compared to the morning group (95% CI, -5.1 to -1.0 mm Hg). Additionally, nighttime diastolic blood pressure in the bedtime group decreased by 1.4 mm Hg (95% CI, -2.8 to -0.1 mm Hg). The rates of nocturnal systolic blood pressure control were 79.0% for the bedtime group versus 69.8% for those taking medication in the morning. Office systolic blood pressure control rates also favored the bedtime dosing, with 88.7% versus 82.2% for the morning group.

Furthermore, the study found no significant differences in the incidence of nocturnal hypotension or adverse effects between the two groups. These findings suggest that bedtime dosing not only enhances nocturnal blood pressure control but also does not compromise daytime efficacy or increase the risk of hypotension during the night.

Dr. Runyu Ye, lead author and researcher at Sichuan University, stated, "Our study provides compelling evidence that bedtime administration of antihypertensive medication can optimize blood pressure management, particularly for nocturnal control, which is crucial given its association with cardiovascular events."

Experts in the field have responded positively to the findings. Dr. Elizabeth Thompson, a cardiologist at the Mayo Clinic, remarked, "This trial adds valuable insights into the timing of antihypertensive therapy. It could reshape how we approach treatment protocols for hypertension, particularly in patients at high risk for nocturnal hypertension."

Conversely, some healthcare professionals urge caution. Dr. Michael Chen, a hypertension specialist at Stanford University, noted, "While the results are promising, further investigations are necessary to evaluate long-term outcomes and the applicability of these findings in diverse populations."

The implications of this research are notable, especially in light of the global hypertension epidemic, which is often underdiagnosed and undertreated. As the World Health Organization (WHO) emphasizes, controlling blood pressure is essential in preventing heart disease and stroke, which remain leading causes of mortality worldwide.

In conclusion, the study advocates for bedtime dosing of antihypertensive medications as a potential new standard in hypertension management, pending further studies to confirm these findings across varied demographic groups. Future research could also explore the underlying mechanisms that contribute to the improved outcomes observed with nighttime dosing, adding depth to our understanding of circadian rhythms in blood pressure regulation.