Blood Pressure Drugs Better at Bedtime

Kidney disease patients who take hypertension drugs at bedtime have lower cardiovascular risk

(RxWiki News) Because high blood pressure can damage the kidneys, many patients with chronic kidney disease take drugs to lower their blood pressure. These patients might find it more beneficial to take their drugs before bed.

Chronic kidney disease patients who take at least one blood pressure drug at bedtime have a lower risk of heart-related complications - such as heart attack, heart failure, stroke, and death - compared to patients who take all their blood pressure drugs upon waking up.

"Talk to your doctor about the best time to take your blood pressure drugs."

People with high blood pressure, or hypertension, take drugs to keep their blood pressure at healthy levels. It is already known that the time of day a patient takes hypertension drugs can affect blood pressure patterns. Ramón C. Hermida, Ph.D., of the University of Vigo in Spain, and colleagues wanted to see if the time of day that kidney disease patients took their blood pressure medications had an effect on their outcomes.

Many doctors already recommend taking some blood pressure drugs before bed. "I have since I was a resident instructed my patient's to take their beta blocker drug therapy in the night time," says Frank Meissner, M.D., an invasive cardiologist and clinical assistant professor of medicine at the Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center. "This class of drugs is often found to be associated with unpleasant weariness and lassitude which is very much made better by taking the drug at bedtime. Additionally, this day/night staggering of drug classes and drug agents has made for a smoother and more even control of blood pressure."

Hypertension and kidney disease can feed off each other in a vicious cycle. High blood pressure causes the heart to work harder, which eventually can hurt blood vessels throughout the body, including vessels in the kidneys. Kidneys with damaged blood vessels can no longer filter wastes and fluids from the body. The excess fluids in the blood vessels can increase blood pressure even more. Hypertension is one of the main causes of kidney failure, or end-stage renal disease.

Due to this link between hypertension and kidney disease, a great deal of kidney patients take medications to lower their blood sugar. Dr. Hermida and colleagues found that kidney disease patients may benefit by taking their blood pressure lowering drugs before bed.

Through a study of 661 people with chronic kidney disease, Dr. Hermida's team found that the risk of death and other heart-related complications was one-third lower in patients who took at least one blood pressure drug at bedtime, compared to those who took all of their drugs when they woke up in the morning.

Patients who took at least one drug at bedtime also had a lower sleep-time blood pressure. In fact, each 5 mmHg drop in sleep-time blood pressure was associated with a 14 percent decrease in the risk of heart-related complications.

"Among patients with [chronic kidney disease] and hypertension, taking at least one antihypertensive medication at bedtime improves control of [blood pressure] and reduces the risk of cardiovascular events," the authors write.

Dr. Meissner, who was not involved in the study, adds support to these findings. "I have little doubt that 'splitting' out drugs over the 24 hour time interval is beneficial not only to the most seriously at risk hypertensive patient, the hypertensive patient with renal dysfunction, but is also beneficial for the antihypertensive without renal disease."

For their study, the researchers randomly assigned the 661 kidney disease patients to take all of their blood pressure drugs upon awakening or to take at least one blood pressure drug at bedtime. The researchers measured participants 48-hour ambulatory blood pressure at the beginning of the study and three months after any change in treatment, or once a year, for a median of 5.4 years..

The results are published in the Journal of the American Society of Nephrology.

Review Date: 
December 14, 2011