Drugs Work Better at Bedtime

Blood pressure medication at night may deliver improved control

(RxWiki News) For optimum management of high blood pressure, one of the keys may be the time of day that the medication is taken. Taking it at night may help patients better control hypertension.

The finding calls into the question the usual way of taking blood pressure medications since many patients take their medications first thing in the morning.

"Ask your pharmacist about taking medications at night."

Ping Zhao, lead study author and a research librarian at Sichaun University in China, said that a morning surge in blood pressure is known to raise the risk of heart attacks and strokes in the first few hours after a person awakens.

Zhao said a growing body of evidence suggests that taking blood pressure medication in the morning means that the full effects are active midday with lesser effects at night and in the morning. He said taking certain medications at bedtime leads to the greatest effects at night and during the early morning.

During the review study, researchers evaluated the results of 21 randomized controlled trials that each lasted at least three weeks and involved 1,993 patients with hypertension. The review found that blood pressure fluctuates in a daily cycle or circadian rhythm. For most who sleep at night and are active during the day, that meant early morning blood pressure surges.

They found that taking blood pressure medications including alpha-blockers and diuretics at night could significantly lower blood pressure over a 24-hour period. However, the finding concerning alpha-blockers and diuretics were limited to results from only a few trials.

There was no significant benefit to taking ACE inhibitors, angiotensin receptor blockers, calcium channel blockers or beta-blockers at any particular time of day.

Dr. Luci Belnick, an internal medicine specialist, said that most doctors simply write "daily" on prescriptions without considering the timing.  But she said it makes no sense for patients with high blood pressure to take their medications early in the morning since this nearly guarantees that the medicine is at its lowest level when the patient needs it the most.

Researchers noted that none of the studies reviewed incidences of stroke and heart attack, and that it remains unknown whether nighttime dosing decreases the risk of early morning cardiac events.

The review study was recently published in The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research.

Review Date: 
October 11, 2011