Acetaminophen is one of the most common pain medicines in the world. Many people use it to treat headaches, fevers, or body aches. Usually, it is taken as a pill and is safe when used properly.
But in hospitals, doctors sometimes give acetaminophen in a different way—directly into a vein. This is called intravenous, or IV, acetaminophen. It works faster than pills and is useful for patients who can’t take medicine by mouth. It also allows doctors to control the dose exactly.
However, a new study shows that this method might have a side effect that many people don’t expect. It can cause a drop in blood pressure.
This drop can happen to anyone receiving IV acetaminophen—not just people who are already very sick. In fact, the study found that six out of ten seriously ill patients had lower blood pressure after getting this medicine through an IV. About one-third of those patients needed treatment to raise their blood pressure again.
The research was done by Thomas Qvistgaard Jepps and his team at the University of Copenhagen. They wanted to understand why this drop in blood pressure happens.
Normally, when someone takes acetaminophen by mouth, the medicine goes through the liver first. But when it’s given through an IV, it bypasses the liver. This changes how the medicine works in the body.
The scientists found that IV acetaminophen affects potassium channels. These are tiny pathways in cells that help control blood pressure. In tests with rats, they were able to block the potassium channels, which stopped the blood pressure drop. This discovery could help doctors find ways to protect patients who need IV pain relief, especially in emergencies.
During the COVID-19 pandemic, hospitals used IV acetaminophen more often, so this issue became even more important.
For people who take acetaminophen as a pill and follow the proper dose, there is no need to worry about blood pressure problems. The concern is mostly for people who get the medicine through an IV in a hospital.
This study is a reminder that the way a medicine is given can affect how it works in the body. Even common medicines like acetaminophen can act differently when used in new ways.
Doctors and nurses should be aware of this risk. They should watch patients closely after giving IV acetaminophen and be ready to act if blood pressure drops.
This new research can help improve hospital care and keep patients safer. It also shows that even simple, well-known medicines can have surprising effects.
If you’re interested in blood pressure health, you may want to read about how diet, omega-3s, tea, coffee, and olive oil may help lower high blood pressure.
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 information about blood pressure, 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.
The full study is published in the journal Atherosclerosis, Thrombosis, and Vascular Biology.
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