Millions of people around the world take medication to control high blood pressure, a condition that increases the risk of heart attacks, strokes, and kidney disease. Doctors often prescribe a pill called chlorthalidone to help lower blood pressure, but a recent study suggests that this drug may come with some unexpected side effects.
Researchers at Columbia University found that people taking chlorthalidone were more likely to experience problems with their potassium levels and kidney function.
What Is High Blood Pressure?
To understand why blood pressure matters, imagine the blood in your body as cars moving on a highway. If traffic moves too fast, it can lead to accidents. Similarly, when blood pushes too hard against blood vessel walls, it can cause damage over time.
This condition is known as high blood pressure (or hypertension). If left untreated, it increases the risk of serious health problems like heart disease, strokes, and kidney failure.
Doctors use different methods to help people manage their blood pressure, including lifestyle changes like eating a healthy diet and exercising regularly. In many cases, medications are needed to keep blood pressure under control.
What Did the Study Find?
The researchers studied health records from over 730,000 people who took blood pressure medication for 17 years. They compared two common drugs—chlorthalidone and hydrochlorothiazide—to see if one was safer than the other.
Both medications were equally effective in preventing heart attacks and strokes. However, people who took chlorthalidone were about three times more likely to develop low potassium levels, a condition known as hypokalemia.
The study found that 6.3% of patients on chlorthalidone had dangerously low potassium, compared to only 1.9% of those taking hydrochlorothiazide.
Why Is Potassium Important?
Potassium is a mineral that helps the body function properly. It plays a key role in keeping muscles and nerves working, including the heart. When potassium levels drop too low, people may feel weak, tired, or experience irregular heartbeats. In severe cases, low potassium can be life-threatening.
The study also found that chlorthalidone users were more likely to have problems with their electrolytes—important chemicals that help the body regulate functions like muscle movement and hydration. Additionally, they had a higher risk of kidney issues, which is concerning since the kidneys play a vital role in filtering waste from the blood.
What Does This Mean for Patients?
This research does not mean that everyone taking chlorthalidone will have these problems. However, it suggests that doctors should monitor patients closely for signs of low potassium or kidney issues.
Currently, many doctors prefer chlorthalidone over hydrochlorothiazide because it was thought to provide longer-lasting blood pressure control. But with these new findings, some may reconsider their choice of medication.
If you take chlorthalidone, there’s no need to panic. Instead, talk to your doctor about any concerns and make sure to have regular check-ups. Blood tests can help monitor potassium levels and kidney function, ensuring that any problems are detected early.
Keeping Blood Pressure Under Control
Whether or not you take blood pressure medication, there are many ways to keep your heart healthy. Eating a diet rich in fruits and vegetables, reducing salt intake, and staying active can all help manage blood pressure naturally. Limiting alcohol, quitting smoking, and finding ways to manage stress—like meditation or daily walks—can also make a big difference.
What’s Next?
Scientists will continue studying these medications to better understand their effects and find the safest treatments for high blood pressure. In the meantime, patients can protect their health by staying informed, having regular doctor visits, and making heart-friendly lifestyle choices.
Blood pressure control is important, but so is choosing the right treatment. With more research, doctors can ensure that patients receive the best care while minimizing risks.
If you care about blood pressure, please read studies about blood pressure drug that may increase risk of sudden cardiac arrest, and these teas could help reduce high blood pressure.
For more information about health, please see recent studies about nutrient that could strongly lower high blood pressure, and results showing this novel antioxidant may help reverse blood vessels aging by 20 years.
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