Antihypertensive medicines are the cornerstone of therapy in patients with hypertension. While we know so well that missing a pill could mean harm, we often wonder what is the best time to take these pills. Let us find out what is the best time in the day to take your blood pressure pills.

Blood pressure varies through the day

The blood pressure shows a lot of variation in an individual during the day. It usually tends to rise just before you wake up early in the morning and remain high during the active hours, peaking up at midday. It begins to fall in the evening and is the low in the night, the lowest being at around 3 to 4 a.m. in the night. The normal drop in blood pressure in the night is called “dipping” and is seen even in hypertensives who have elevated average blood pressure. In some hypertensive patients, the blood pressure does not demonstrate the 10% dip during the night. This can be documented using the 24 hr ambulatory blood pressure monitoring and these individuals are called “non-dippers”. There is ample evidence that “non-dippers” have a higher risk of strokes and heart attacks in the early morning hours. 

How do blood pressure medicines work?

While medicines have a predictable action, their effect on the body at different times of the day may not be uniform. The science of identifying what time suits best for a particular medicine to have its best effect is called “chronotherapy”. Timing treatment in hypertension yields the best results.

There are different types of blood pressure medicines and many of them are meant to be taken once per day. Once you take a pill, the action of the drug peaks anywhere from 3 hrs to 15 hrs after the dose. This is when most of the blood pressure-lowering effect occurs. The peak concentration of the drug has to coincide with the time of the day when the blood pressure is at its highest. Therefore, taking a blood pressure pill in the night will control the blood pressure in the morning hours when it tends to peak.

Most blood pressure medicines work best when taken during bedtime. This includes:

  • Angiotensin receptor blockers (ARBs): These are the most commonly prescribed antihypertensive medications and include Losartan, Telmisartan, Olmesartan and Valsartan 
  • ACE inhibitors (ACEI): These include Enalapril, Ramipril, Perindopril and Lisinopril 
  • Calcium channel blockers (CCBs): These include Amlodepin, Cilnidipine and Benidipine   
  • Beta Blockers (BBs): These include Metoprolol, Nebivolol and Bisoprolol                                     

A few medications that are best taken in the morning: ·      

  • Diuretics: These are the water pills. They increase the urination and help the kidneys get rid of the extra water. Since they can disturb sleep from frequent trips to the bathroom if taken in the night, they are best taken during the day. These include Hydochlorothiazide, Chorthalidone and Indapamide

While this strategy works for most individuals with normal sleep cycles, it may not for people who work in shifts. Having consistent times for taking medicines is important in these patients. Also, the elderly may need individualized schedules to avoid falls from blood pressure drops due to medicines. 

What does the evidence say?

As a part of the Hygia Chronotherapy Trial, Researchers in Spain followed nearly 19000 men and women with high blood pressure for over an average of 6 years and found that those who took all their pills at bedtime had lower blood pressure through the day than those who took their pills in the daytime. What was even more exciting is the fact that the bedtime strategy nearly halved the risk of having a heart attack, the risk of having heart failure, risk of a stroke, and also the risk of having angioplasty or bypass surgery. The findings were consistent regardless of the age, sex, and presence of other diseases like diabetes or kidney disease. The volunteers underwent regular blood pressure tracking and also an annual 48 hr ambulatory blood pressure monitoring study. While it may be uncertain whether these findings will apply to other ethnic groups, the study is impressive and lends support to the concept of taking blood pressure medicines at bedtime. 

Best practices for taking blood pressure medicines

1. Consistency is the key. Don’t skip your pills. Following a routine will prevent blood pressure variations and protect against damage.

2. Take most, if not all of your blood pressure medicines at bedtime. Bedtime dosing provides better control and reduces the cardiovascular risk.

3. Do not make changes in your medicines or schedules by yourself. Speak to your doctor regarding this.