Chlorthalidone is a medicine that has been used by doctors for many years to help people lower their high blood pressure. But now, a big study from Columbia University is raising some new concerns about how safe it really is.
The researchers found that while this medicine is good at protecting the heart, it may also cause serious side effects that people should know about.
High blood pressure, also called hypertension, means the blood is pushing too hard against the walls of your arteries, like water rushing through a hose with too much pressure. Over time, this pressure can hurt your heart, brain, kidneys, and other important organs. That’s why it’s important to keep blood pressure at a healthy level.
To manage high blood pressure, doctors often recommend changes in lifestyle—such as eating better, exercising more, and reducing stress—along with medicine.
One common drug used is chlorthalidone, which is a type of water pill, also called a diuretic. It works by helping the body get rid of extra salt and water, making it easier for blood to flow and lowering blood pressure.
In this new study, the researchers looked at medical records from more than 730,000 people over 17 years. They compared chlorthalidone with a similar drug called hydrochlorothiazide. Both helped lower blood pressure and prevented serious health problems like heart attacks and strokes. However, there were big differences when it came to side effects.
People who took chlorthalidone were three times more likely to develop a problem called hypokalemia. This means their potassium levels dropped too low.
Potassium is an important mineral that helps your heart, muscles, and nerves work properly. If you don’t have enough, you might feel very tired, weak, or have muscle cramps. In serious cases, it can cause dangerous heart problems.
Here’s what the study showed: 6.3% of people who took chlorthalidone developed low potassium, compared to only 1.9% of those who took hydrochlorothiazide. That’s a big difference. People on chlorthalidone also had more problems with other minerals in their blood, and with their kidneys.
This doesn’t mean everyone should stop taking chlorthalidone. Many people use it safely. But it does mean that people taking this medicine should have regular blood tests to make sure their potassium levels and kidney function stay in a safe range.
If you take chlorthalidone and feel very tired, weak, or have muscle pain, it’s smart to tell your doctor. Don’t stop the medicine on your own—your doctor can help decide if it’s the right medicine for you or if another option would be better.
Doctors like chlorthalidone because it stays in the body longer and may control blood pressure better than other drugs. But with this new research, some may choose a different medicine, especially for patients who are at risk of low potassium or kidney problems.
It’s important to remember that medicine is just one part of managing high blood pressure. Eating healthy foods like fruits and vegetables, cutting down on salt, staying active, not smoking, and keeping stress levels low are all helpful. Even a short walk every day can make a difference.
This new research shows that while blood pressure medicine is helpful, it’s not perfect. More studies will continue to look at the long-term effects of these drugs. In the meantime, staying informed and talking openly with your doctor is the best way to stay healthy.
If you care about high blood pressure, please read studies that drinking tea could help lower blood pressure, and early time-restricted eating could help improve blood pressure.
For more health information, please see recent studies about added sugar in your diet linked to higher blood pressure, and results showing vitamin D could improve blood pressure in people with diabetes.
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