Taking your blood pressure (BP) medication before you go to sleep at night may actually help protect the heart from cardiovascular events down the road. The reason for this is that taking BP meds at nighttime seems to work with one’s circadian rhythm (or daily cycle) and boosts the effectiveness of the drugs.

Taking one’s BP meds at night may work by complementing the body’s natural rhythms and affecting the chemicals that control blood pressure. Since many doctors tell people to take their meds during the morning, this recommendation may need to be reevaluated in the future.

Ramon C. Hermida and his colleagues at the University of Vigo in Spain followed over 2,100 people with high blood pressure whose average age was 56. Half of the participants took their medications at night before bed and the other half took them in the morning, as is usually convention. Periodically over the next five years, the researchers monitored the participants’ blood pressures, using a device that records BP over a 48 hour period. This gives a good idea of how BP fluctuates throughout the day and night. They also, of course, tracked how many of the men and women suffered from heart attack, stroke, or angina (chest pain) during the course of the study.

The team found that 62% of the patients taking their pills at night had controlled BP over the next five years, while only 53% of those taking their meds in the morning had controlled BP. In addition, many more people in the nighttime group had reduced BP during the nighttime hours, which what we want — in fact, BP that does not dip at night is linked to more heart problems down the road. And finally, those who took their meds at night suffered about one-third as many heart attacks, stroke, and instances of chest pain as people taking their meds in the morning.

Taking one’s BP meds at night may work by complementing the body’s natural rhythms and affecting the chemicals that control blood pressure. Since many doctors tell people to take their meds during the morning, this recommendation may need to be reevaluated in the future. In the meantime, talk to your doctor about making any changes to your regular routine — he or she will discuss the benefits and advise you about the safest way to do so.