Evening dosing of blood pressure medication not better than morning dosing, according to study

More than one billion people have high blood pressure worldwide and it is the leading global cause of premature death, accounting for almost ten million deaths in 2015.

Previous evidence has shown that blood pressure medication, also known as antihypertensive drugs, taken in the evening rather than in the morning reduce night-time blood pressure. However, the question has always been whether nighttime dosing is better or worse than morning dosing in preventing medical episodes associated with high blood pressure, such as strokes and heart attacks.

The TIME (Treatment In the Morning vs Evening) study, led by researchers at the Medicines Monitoring Unit (MEMO) and the Hypertension Research Centre, followed more than 21,000 patients with high blood pressure for over five years.

The trial concluded that protection against heart attack, stroke and vascular death is not affected by whether antihypertensive medications are taken in the morning or evening, despite previous studies suggesting otherwise.

Principal investigator Professor Thomas MacDonald, from the University’s School of Medicine, presented the trial findings at the European Society of Cardiology (ESC) Congress 2022 this week.

“TIME was one of the largest cardiovascular studies ever conducted and provides a definitive answer on the question of whether blood pressure lowering medications should be taken in the morning or evening,” said Professor MacDonald.

“The trial clearly found that heart attack, stroke and vascular death occurred to a similar degree regardless of the time of administration. People with high blood pressure should take their regular antihypertensive medications at a time of day that is convenient for them and minimises any undesirable effects.”

Professor Isla Mackenzie, also from the University of Dundee, who co-led the study, added, “This study was successful due to the commitment and dedication of more than 21,000 patients from across the UK who engaged with the trial over a number of years, helping us to answer this important question about the best timing of taking blood pressure medicines. TIME is one of the largest remote blood pressure trials, not involving any in-person study visits, ever done.”

The study was funded by the British Heart Foundation and supported by the British and Irish Hypertension Society and the National Institute for Health and Care Research in the UK.

Professor Sir Nilesh Samani, Medical Director at the British Heart Foundation, said, “This is important news for the millions of people in the UK who take medication to lower their blood pressure.

“High blood pressure is a major risk factor for heart attacks and strokes. We know that effective treatment with blood pressure lowering medication is vital to reduce this risk. These results show that the time of the day people take their blood pressure tablets does not matter and they should take them at the time that suits them best."

TIME was a large prospective, randomised trial conducted to test whether evening dosing of antihypertensive medication improved major cardiovascular outcomes compared with morning dosing. A total of 21,104 patients were randomised, 10,503 to evening dosing and 10,601 to morning dosing.

Information on hospitalisations and deaths was obtained from participants by email and through record linkage to national databases. Further data was gathered from family doctors and hospitals.