This study suggests that patients can take antihypertensive medications safely at any time of day.

Blood pressure (BP) typically dips overnight and surges in the morning. Adverse cardiovascular (CV) events occur more frequently with the usual morning surge and in people who do not have usual diurnal BP variation. Two studies have reported a marked reduction in adverse CV events when antihypertensive medications are taken at night rather than in the morning (e.g. Eur Heart J 2020; 41: 4565-476), but those trials have been controversial.

British researchers randomised 21,000 adults with treated hypertension to take their usual daily medications either in the morning (between 6 a.m. and 10 a.m.) or at night (between 8 p.m. and midnight). Participants completed periodic online questionnaires about their adherence, medication side effects and adverse CV events. CV events were verified using national hospitalisation and death databases.

After median follow up of five years, the morning and night dosing groups had similar rates of a composite CV outcome (i.e. CV-related death, nonfatal myocardial infarction or stroke; 0.72 and 0.69 events per 100 patient-years, respectively) and a variety of secondary CV outcomes. Dizziness, indigestion, diarrhoea and myalgia occurred more commonly with morning dosing, whereas nocturia occurred more commonly with evening dosing. Using home monitors, patients assigned to morning dosing had slightly but significantly higher morning BPs and lower evening BPs than did patients assigned to evening dosing.

Comment: In this study, dosing in the morning or evening did not affect CV outcomes significantly; the results therefore suggest that patients may take their antihypertensive medications at the time of day that is most convenient for them. However, given the conflicting findings between this trial and previous trials that showed better outcomes with evening dosing, the controversy over optimal timing might not be over. Additional trials addressing this issue are being conducted in Canada (BedMed and BedMed-Frail).
BRUCE SOLOWAY MD
Associate Professor Emeritus of Family and Social Medicine, Albert Einstein College of Medicine, Bronx, New York, USA.

Mackenzie IS, et al. Cardiovascular outcomes in adults with hypertension with evening versus morning dosing of usual antihypertensives in the UK (TIME study): a prospective, randomised, open- label, blinded-endpoint clinical trial. Lancet 2022; 400: 1417-1425.

This summary is taken from the following Journal Watch title: Cardiology.