MONDAY, Oct. 24, 2011 (HealthDay News) -- For the millions of Americans on blood pressure-lowering drugs, a new study suggests that taking the pills at bedtime may be best.
It was known that taking blood pressure medications at different times of the day can affect patients' blood pressure patterns, but the impact on health wasn't known.
The new Spanish study included 661 patients with chronic kidney disease and hypertension. Half of them took their prescribed blood pressure-lowering drugs at bedtime and half took their medications first thing in the morning.
After an average follow-up of 5.4 years, the researchers found that patients who took at least one blood pressure-lowering drug at bedtime had better control of their blood pressure and were about one-third as likely to suffer a heart-related event such as heart attack, heart failure or stroke.
The team at the University of Vigo also found that sleep-time blood pressure provided a much more accurate measure of heart health than wake-time blood pressure.
The study was published online Oct. 24 in the Journal of the American Society of Nephrology.
"Our results indicate that cardiovascular event rates in patients with hypertension can be reduced by more than 50 percent with a zero-cost strategy of administering blood pressure-lowering medications at bedtime rather than in the morning," study author Ramon Hermida wrote in a journal news release.
One U.S. doctor said taking advantage of "chronotherapy" -- timing drug delivery to a patient's biorhythms -- might have real value.
"Physicians don't commonly specify which time of day patients should take their medications; however, most patients with hypertension take their antihypertensive drugs in the morning. Upon taking these medications, patients oftentimes complain of side effects, most commonly, fatigue and drowsiness," noted Dr. Robert Graham, an internist at Lenox Hill Hospital in New York City.
He believes the study reveals a "low-cost, win-win scenario" of better adherence to blood pressure medications and higher effectiveness when they're taken in the evening versus the morning. "As a result, chronotherapy may help minimize the side effects, and maximize the beneficial effects of antihypertensive medications," Graham said.
Another expert agreed.
"The notion of nocturnal medication use is not new," said Dr. Howard S. Weintraub, clinical director of the Center for the Prevention of Cardiovascular Disease at NYU Langone Medical Center, New York City. "This strategy may be especially effective with the use of [blood pressure drugs such as] ACE inhibitors, angiotensin receptor blockers or direct renin inhibitors."
Weintraub added that, "while taking a diuretic at bedtime may have a disruptive effect on sleep, in general, I think many of us have been doing this for some time with the intent to best control nocturnal blood pressure and to also mitigate some of the usual spike in blood pressure that occurs early in the morning (starting around 5 am)."
In the United States, about one in three adults has high blood pressure.
The American Heart Association has more about blood pressure medications.