A new European study has raised concerns about a widely used blood pressure medicine, showing that taking it in high doses may increase the risk of sudden cardiac arrest — a dangerous condition where the heart stops beating without warning.
The research was conducted by the European Sudden Cardiac Arrest network and focused on two popular drugs used to treat high blood pressure and chest pain: nifedipine and amlodipine.
Both drugs belong to the same family of medications, known as calcium channel blockers, which work by relaxing blood vessels so blood can flow more easily. This helps reduce strain on the heart and has made these medicines a common choice for millions of people around the world.
Sudden cardiac arrest is not the same as a heart attack. In a heart attack, blood flow to part of the heart is blocked. In sudden cardiac arrest, the heart’s electrical system malfunctions, causing the heart to suddenly stop beating altogether. When that happens, blood flow to the brain and other vital organs stops almost instantly.
Unless treatment is given right away — usually CPR or a shock from a defibrillator — the condition is almost always fatal. It is responsible for roughly half of all heart-related deaths in Europe and one in every five natural deaths overall.
In this new study, researchers found that people taking high doses of nifedipine were more likely to experience sudden cardiac arrest than those who were not taking it or who were taking smaller doses.
The other drug, amlodipine, did not show the same risk, even though it works in a similar way. This discovery was surprising because both medications have been used safely for decades.
To reach their findings, the scientists analyzed health data from thousands of people across Europe. They compared the medical histories of patients who suffered sudden cardiac arrest with those who had not.
A clear pattern appeared: the higher the nifedipine dose, the greater the risk of cardiac arrest. However, the researchers were careful to point out that this type of study can only show a link, not direct cause and effect.
They also cautioned that patients should not panic or stop their medications suddenly. Stopping blood pressure medicine without guidance can be dangerous and may cause blood pressure to spike, increasing the risk of heart attack or stroke.
Instead, anyone taking nifedipine — especially in high doses — should talk to their doctor about the safest way to continue or adjust their treatment.
The researchers stressed that more studies are needed to confirm these findings and understand exactly why high doses of nifedipine might pose this risk. It’s possible that at very high levels, the drug affects how the heart’s electrical signals are controlled, which could lead to irregular heart rhythms. But more work is needed to know for sure.
For now, doctors may want to be cautious when prescribing high doses of nifedipine, particularly for people who already have heart problems or who take other medications that affect heart rhythm. They might consider lower doses or alternative treatments, such as amlodipine, which did not show the same risk in this study.
This discovery serves as a reminder that even long-trusted medicines should be reviewed as new evidence emerges. Our understanding of drugs and their effects continues to evolve, and research like this helps make treatments safer for everyone.
In short, nifedipine remains an important and helpful drug for managing high blood pressure and chest pain, but this study highlights the need for careful monitoring and open communication between patients and doctors. Using the right dose — and staying informed — can make all the difference for heart health.
If you care about blood pressure, please read studies about common blood pressure medication that may extend your healthy life span and common high blood pressure drug linked to sudden cardiac arrest.
For more about blood pressure, please read studies that timing matters when taking high blood pressure pills and 1 in 5 people with high blood pressure taking a drug worsen the disease.
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