Should You Take Your Blood Pressure Medications at Bedtime or In the Morning?

What once was clear is now muddied, muddled and/or opaque. Equipoise rules.

In 2019 the skeptical cardiologist wrote about a trial that he thought was practice changing.

a study published in European Heart Journal in October has demonstrated that routine ingestion of BP meds at bedtime as opposed to waking results in improved 24 hour BP control with enhanced decrease in asleep BP and increased sleep-time relative BP decline (known as BP dipping.)

More importantly, bedtime BP med ingestion in this randomized trial of over 19 thousand hypertensive Spaniards resulted in highly significant reductions in cardiovascular events including death, heart attack, heart failure and stroke over a 6 year median follow-up

The so-called Hygia Chronotherapy Trial was extremely well done and the results are powerful and should modify clinical practice immediately.

The Hygia Chronotherapy Trial did change my practice and I began advising patients to take their BP meds at night.

My sense in following lots of patients who had made the transition to bedtime BP meds was that daytime BP in general was better.

Since 2019, however, a large randomized trial has been published showing no benefit of evening dosing of antihypertensives.

The TIME Trial published in 2022; followed 21,104 individuals in the United Kingdom and reported that there was no difference in the primary outcome of vascular death, myocardial infarction, or stroke between groups randomized to evening versus morning dosing of antihypertensive medications.

When I saw this trial result I was quite puzzled and I stopped advising patients to take BP meds at bedtime. However, I did not advise current patients to modify when they were taking their meds if they were doing well.

Several analyses critical of the Hygia Chronotherapy paper have been published and it should be noted that this study and most of the data supporting bedtime BP med dosing comes from one Spanish scientist and in a Spanish population.

In 2022, various hypertension groups looked at the conflicting evidence following the TIME trial and wrote a statement entitled "Bedtime dosing of antihypertensive medications: systematic review and consensus statement: International Society of Hypertension position paper endorsed by World Hypertension League and European Society of Hypertension."

Here's what these experts concluded:

Eight published outcome hypertension studies involved bedtime dosing of antihypertensive drugs, and all had major methodological and/or other flaws and a high risk of bias in testing the impact of bedtime compared to morning treatment.

In other words, the published results of trials in this space do not allow us to know with any certainty what the best time to dose BP meds is.

We have reached clinical equipoise on this issue.

The expert statement goes on to say:

Three ongoing, well designed, prospective, randomized controlled outcome trials are expected to provide high-quality data on the efficacy and safety of evening or bedtime versus morning drug dosing. Until that information is available, preferred use of bedtime drug dosing of antihypertensive drugs should not be routinely recommended in clinical practice. Complete 24-h control of BP should be targeted using readily available, long-acting antihypertensive medications as monotherapy or combinations administered in a single morning dose.

It is not clear to me why these authors are recommending "a single morning dose."

I tweak the timing of BP medications depending on what my patient's AM and PM BPs are doing and I often use twice-daily dosing if appropriate.

A recent article in the American Journal of Medicine provides a succinct summary of the relevant trials and their flaws and concludes:

it is our recommendation that time of day is not of the essence when administering blood pressure medication. Rather, patients should consistently take their medications at a time most convenient for them.

Whether you take BP meds in the morning or at night, the most important thing is to regularly monitor BP at home using the right technique and equipment (see my summary here) and work with your doctor to find the right combination of medications and timing that achieves 24 hour BP control with no side effects.

Semichronotherapeutically Yours,

-ACP (TSC)

N.B. Since 2019 I have been taking my BP meds at night. (FYI I’m not taking a thiazide diuretic which one might think causes extra peeing.) Recently, I have been experimenting with taking them around dinner time with the aim of reducing the volume of water I consume at bedtime and thus minimizing sleep disruptions due to bathroom trips. This has been variably successful.

There are associations between shorter (and longer) sleep duration and blood pressure but they are of the MOOP variety. The bottom line on sleep quality is how you feel the next day.