High blood pressure, also known as hypertension, affects millions of people around the world.
If it is not well controlled, it can damage blood vessels over many years and greatly increase the risk of heart attack, stroke, heart failure, kidney disease, and other serious health problems.
Because of these dangers, many people need long-term medicine to keep their blood pressure at a healthy level.
Doctors often prescribe medicines called diuretics, sometimes known as water pills, to lower blood pressure. These medicines help the body remove extra salt and water through urine, reducing the pressure inside blood vessels. Two of the most commonly used diuretics are chlorthalidone and hydrochlorothiazide.
A new study by researchers at Columbia University has raised questions about the safety of chlorthalidone for some patients. The findings, published in the Annals of Internal Medicine, suggest that while the medicine lowers blood pressure effectively, it may also increase the risk of certain side effects compared with hydrochlorothiazide.
The research team analyzed health records from more than 730,000 people who took blood pressure medicines over a 17-year period. They compared the two drugs to see whether one provided better protection against heart attacks and strokes and whether one caused more unwanted health problems.
The results showed that both medicines worked equally well at preventing heart attacks and strokes. However, people taking chlorthalidone were much more likely to develop low potassium levels, a condition known as hypokalemia.
About 6.3% of people taking chlorthalidone developed low potassium compared with 1.9% of those taking hydrochlorothiazide.
Potassium is an important mineral that helps the heart, muscles, and nerves function normally. When potassium levels become too low, people may feel weak, tired, or develop muscle cramps. In more serious cases, low potassium can lead to dangerous changes in heart rhythm, particularly in people who already have heart disease.
The researchers also found that people taking chlorthalidone had a greater risk of kidney problems and other electrolyte imbalances. Electrolytes, including potassium and sodium, help regulate many vital body functions such as muscle movement, nerve signals, and maintaining a steady heartbeat.
These findings do not mean that everyone taking chlorthalidone will experience side effects. Many people use the medicine safely and benefit from its blood pressure-lowering effects. However, the study suggests that doctors may need to monitor blood tests more closely, especially in patients who already have kidney disease or other medical conditions that increase the risk of electrolyte problems.
Experts stress that patients should never stop taking prescribed blood pressure medicine without first speaking to their healthcare provider. Suddenly stopping treatment can cause blood pressure to rise, increasing the risk of serious complications.
If patients notice unusual symptoms such as severe weakness, irregular heartbeat, dizziness, or muscle cramps, they should seek medical advice promptly.
In addition to medication, healthy lifestyle habits remain an important part of controlling blood pressure. Eating a balanced diet, limiting salt, exercising regularly, maintaining a healthy weight, avoiding smoking, reducing alcohol intake, and managing stress can all help protect heart health.
This large study provides valuable information that may help doctors choose the most suitable blood pressure medicine for each patient while improving long-term safety.
If you care about high blood pressure, please read studies that early time-restricted eating could help improve blood pressure, and natural coconut sugar could help reduce blood pressure and artery stiffness.
For more health information, please see recent studies about How to eat your way to healthy blood pressure and results showing that Modified traditional Chinese cuisine can lower blood pressure.
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