Blood Pressure & Timing

Mar 26, 2020

By Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

A co-worker of mine has a kid named Mika. Mika happens to be in the same grade as my son Eric. Mika's birthday shares the date of my wedding anniversary. Like most kids, Mika is a big fan of her birthday. But, in 2021 her birthday will be extra special. In 2021, Mika's birthday cake will have more candles on it than her grandmother's birthday cake ever had. Mika has been looking forward to her 2021 birthday for a long time. She is very excited to finally be older than her grandmother.

Timing is also important when it comes to blood pressure. Blood pressure follows a predictable pattern throughout the day. We call it a circadian rhythm. Blood pressure slowly starts rising between 3 and 6 am. Then it rises quickly once you wake up. It continues to increase for the next 4 to 6 hours in response to increases in cortisol, catecholamines and renin. Blood pressure then dips down between midnight and 3 am. And the cycle repeats.

Several years ago, there was a lot of excitement about people taking their blood pressure pills at bedtime. It was called "chronotherapy". The theory went like this. A lot of heart attacks and other heart issues happen between 6 and 10 am. That coincides with the morning circadian rise in blood pressure. Also, some people don't have a dip in blood pressure at night. We call them non-dippers. We think non-dipping puts them at risk of heart issues. So, researchers looked to see if taking medications at bedtime would reduce that early morning spike in blood pressure and fix the non-dippers.

Lately, studies have come out that say it really might help to move blood pressure pills to bedtime. It seems like when people who are on three blood pressure pills move one of them to bedtime, they are less likely to have heart problems. It seems like people whose blood pressure doesn't dip at night benefit from taking their blood pressure medications at bedtime. Bedtime dosing might also be a good idea for people with really high blood pressures in the morning.

Moving blood pressure pills to bedtimes isn't all sunshine and lollipops. Taking a blood pressure pill at bedtime can make you dizzy if you get up in the middle of the night to go to the bathroom. Since many people on blood pressure pills are elderly, that can lead to falls and broken bones. Some blood pressure pills are called diuretics. That means they make you urinate more often. And as anyone of a certain age will tell you, getting up to pee at night already messes with their sleep. Having your blood pressure pill make you pee more often at night is not a welcome idea. Finally, there is a little controversy about the bedtime blood pressure pill trials. Some of the bedtime trials seem to imply that moving blood pressure pills to bedtime instead of the morning has more benefit than going from no blood pressure pills to some blood pressure pills. And that doesn't make a lot of sense.

Let's back up a bit. What is high blood pressure? Your heart is a pump. It squeezes blood through pipes we call blood vessels. These pipes take blood out to the top of your head and the tips of your toes. The blood does lots of important things, but some of its most important jobs are to get food and oxygen out to all the cells and bring back all the waste and carbon dioxide for disposal. To get the blood moving through the blood vessels, the heart has to squeeze the blood. We call this blood pressure. You will notice the doctor always talks about two blood pressure numbers. They will say things like they want your blood pressure less than 140/90. The top number is the amount of pressure the heart has to exert to get the blood through the pipes when it squeezes. This top number is called the systolic blood pressure. The amount of pressure left over in the pipes after the heart muscle relaxes is called the diastolic blood pressure. Unlike the pipes in your house, blood vessels are flexible. They are designed to expand and contract as pulses of blood go through them. But blood vessels can harden and get plugged. When this happens, the amount of force the heart must exert to get the blood to flow goes up. This is called high blood pressure or hypertension. Why should you care if you get high blood pressure? High blood pressure increases your chance of stroke, heart attack, heart failure, kidney disease and other problems.

How you can treat high blood pressure without medication? If you lose weight, exercise, and change your diet you can reduce your blood pressure. If you lose 10 kg or 22lbs, you can reduce your blood pressure by about the same amount as being on one blood pressure pill. Diet changes to reduce blood pressure include reducing the amount of salt, alcohol and saturated fats you consume. You should also increase the amount of fruit and vegetables you eat. If you reduce your salt intake to less than about 1 teaspoon per day, that can also reduce your blood pressure by about the same amount as one blood pressure pill. The tricky part is most of the salt in our diet isn't from what we add at the table with the salt shaker. Most of it is from eating processed food. There is a lot of salt added when a food is packaged for you. The only way to know for sure how much salt you eat is to prepare all or most of your own food at home. And that can be a very tall order for many people.

What are the important things to remember about timing and blood pressure pills? As a pharmacist, I'm much more interested that you take the pills than the timing. Unfortunately, about 1 in 4 people who are put on blood pressure pills stop taking them within six months. About 1 in 2 people stop their blood pressure pills within a year of starting them. It is unfortunate, but understandable why so many people quit their blood pressure pills. They went to the doctor feeling fine. Their doctor checked their blood pressure, found it was high, and wrote them a prescription for a pill. In the best case scenario, the pill costs them money every month and they feel no different. In the worst case scenario, the pill costs them money, and gives them some annoying side effects. So, within six months the patient goes from feeling well to spending money every month on something that makes them feel worse. Again, no wonder they quit. But, if you are put on a blood pressure pill, give it a chance. Talk to your pharmacist about managing the side effects. Although high blood pressure doesn't hurt, a stroke or heart attack does. Taking your blood pressure pills consistently is much more important than what time of day you take them. Find a time of day you are going to remember, and just take them.

The timing of birthdays is on Mika's mind. Mika and her grandmother both turn 15 in 2020. Mika will turn 16 in 2021. Mika's grandmother won't turn 16 until 2024. If you haven't guessed the riddle yet, Mika's grandmother is a leap year baby. Her birthday is on February 29th. Mika's grandmother gets four times fewer birthday's than the rest of us. In 2021, her granddaughter, Mika, will have more birthdays under her belt than her grandmother. I wonder if Mika's grandmother will wait until her 18th birthday in 2032 to have her first drink of alcohol?

As always if you have any questions or concerns about these products, ask your pharmacist.

The information in this article is intended as a helpful guide only. It is not intended to be used as a substitute for professional advice. If you have any questions about your medications and what is right for you see your doctor, pharmacist or other health care professional.


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