Best Time of Day to Take Blood Pressure Medications

Labels on prescription drugs often tell you to take a tablet "once a day" without specifying the best time of day to take them—and in some cases timing doesn't matter. With blood pressure medications, however, it can matter when you take them. The best time of day to take blood pressure drugs varies depending on which ones you take (there are many), as well on your reason for taking them and any other health issues you may have.

Blood pressure tends to vary during the day. It tends to be higher when you wake up in the morning and during the morning hours, and lower in the night and when sleeping. However, there are people whose blood pressure does not drop at night; researchers call these "non-dippers."

Most blood pressure medications have been designed for ease of use, meaning they are meant to be taken once per day. Even so, these medications are not equally effective over the entire 24-hour period during which they are active.

There are several different types of blood pressure medications that have different mechanisms of action and are thus best taken at certain times of day.

Medications that are best taken in the morning:

• Diuretics, or “water-pills": These include Diuril (chlorothiazide) and Lozol (indapamide), and work by helping your kidneys get rid of extra water in your body. Because diuretics can cause you to urinate more (resulting in nighttime trips to the bathroom), it's best to take them in the morning. If you need a second dose, take it by mid-afternoon.

Some other common blood pressure medications that are best taken at bedtime include:

• ACE inhibitors (angiotensin-converting enzyme inhibitors), including Lotensin (benazepril hydrochloride) and Vasotec (enalapril maleate)
• ARBs (angiotensin II receptor blockers), such as Avapro (irbesartan)
• Beta blockers, such as Lopressor (metoprolol)
• Calcium Channel blockers, such as Norvasc (amlodipine besylate)

These drugs are usually taken at bedtime because they can cause drowsiness. More importantly, they are often designed to release the medication slowly so that they remain most effective in the morning hours when blood pressure tends to be at its peak. As you age, your blood pressure no longer dips during your sleep like it does when you’re younger, increasing your risk for stroke and heart attack in the morning.

Research backs up the importance of nighttime dosing. A 2013 study from Spain found that non-dippers, whose blood pressure remains elevated through the night, may benefit most from taking a bedtime dose. Doing so provides better control and may help reduce the risk of heart attack or stroke.

A 2015 study in the journal Diabetologia showed that taking these medications at night reduced the risk of type 2 diabetes in people with hypertension. Based on this, the American Diabetes Association's Standards of Medical Care in Diabetes—2017 says that doctors should consider administering one or more hypertensive medications at bedtime.

For people with normal sleep cycles, maintaining a routine dosing schedule is easier since the rise and fall in blood pressure will tend to be consistent.

However, if you work a second or third shift job or have other reasons to consistently be awake at non-standard hours, you may want to adjust your routine to account for these differences.

Talk to your doctor if you are unsure about when to take your blood pressure medications. There are some drugs that, while they can be taken at any time, cannot be quickly switched from one time to another without some monitoring and adjustment. Interactions with your other medications, food, and drink must also be taken into consideration.

In the end, your blood pressure medication will work best when you take it consistently, so any change of the timing of your dosage should be considered carefully. Work with your doctor to decide on an administration plan that meets your schedule and lifestyle needs.