A new study from Columbia University is raising concerns about a common drug used to treat high blood pressure.
The research looked at two popular diuretics—chlorthalidone and hydrochlorothiazide—which are often used to help lower blood pressure by helping the body remove extra salt and water.
While both medications work well to reduce blood pressure and lower the risk of heart attacks and strokes, the study found that chlorthalidone may cause more serious side effects than hydrochlorothiazide.
The study analyzed 17 years of health data from more than 730,000 patients. Both drugs were equally good at preventing major heart problems like strokes, heart attacks, and hospital stays for heart failure.
But patients who took chlorthalidone had a much higher chance of developing problems with their electrolytes and kidneys.
One major issue was low potassium levels, a condition called hypokalemia. Potassium is important for heart and muscle function. If levels drop too low, it can lead to dangerous heart rhythms and other serious problems.
In the study, 6.3% of patients taking chlorthalidone developed low potassium, while only 1.9% of those on hydrochlorothiazide did. Even when patients took lower doses of chlorthalidone, the risk remained high.
Other side effects of chlorthalidone included low sodium levels (hyponatremia), which can cause confusion and increase the chance of kidney failure. The study also found that people taking chlorthalidone were more likely to develop type 2 diabetes.
These findings are important because current treatment guidelines often recommend chlorthalidone over hydrochlorothiazide.
This advice is based on older studies that suggested chlorthalidone has longer-lasting effects on blood pressure. But this new research suggests that the risk of side effects might outweigh those benefits for many people.
This is not the first time doctors have worried about chlorthalidone. Earlier studies have also shown that it may cause more problems with electrolytes than hydrochlorothiazide.
Because of the new findings, some experts believe it may be time to update medical guidelines. They argue that the risks of chlorthalidone should be more carefully weighed against its benefits.
For people already taking chlorthalidone, the study’s authors recommend regular blood tests to check for side effects like low potassium or sodium levels. It’s important not to stop taking any medication without speaking to a doctor first.
High blood pressure is a serious condition that can lead to heart disease, stroke, and kidney failure if not treated properly. Medicines like diuretics play a key role in managing blood pressure, but lifestyle changes are also important. Eating healthy, staying active, and reducing stress can all help keep blood pressure in check.
This study, led by Dr. George Hripcsak and published in the journal JAMA Internal Medicine, shows the importance of looking at both the good and bad sides of any medicine. Choosing the right drug should involve a careful look at how well it works and what risks it might bring.
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