Acetaminophen is one of the most widely used pain medicines in the world. Many people take it to ease headaches, reduce fever, or relieve body pain.
It is usually taken as a tablet or capsule and is considered safe when used at the correct dose. Because it is easy to use and widely available, it is often the first choice for mild to moderate pain.
In hospitals, however, doctors sometimes use a different method to give this medicine. Instead of giving it as a pill, they may give it directly into a patient’s vein. This method is called intravenous, or IV, delivery.
It is often used when patients cannot swallow pills, such as after surgery or during serious illness. It also works faster and allows doctors to control the exact amount of medicine the patient receives.
Even though IV acetaminophen is helpful in many situations, new research suggests it may have an unexpected effect on the body. The study found that this method of giving the drug can cause a drop in blood pressure.
Blood pressure is important because it helps push blood through the body, delivering oxygen and nutrients to organs. If blood pressure drops too much, it can make a person feel weak, dizzy, or even lead to more serious problems.
What surprised researchers is that this drop in blood pressure does not only happen in very sick patients. It can also occur in people who are otherwise stable but receive the medicine through an IV.
In fact, earlier observations showed that about six out of ten critically ill patients experienced a drop in blood pressure after receiving IV acetaminophen. Around one in three of these patients needed treatment to bring their blood pressure back to a safe level.
The study was led by Thomas Qvistgaard Jepps and his research team at the University of Copenhagen. Their goal was to understand why this effect happens. When acetaminophen is taken as a pill, it passes through the liver before entering the rest of the body. The liver helps process the drug and controls how it works.
However, when the drug is given through an IV, it goes directly into the bloodstream and skips the liver at first. This changes how the body reacts to it.
The researchers found that this difference affects small structures in the body called potassium channels. These channels help control how blood vessels open and close, which directly affects blood pressure.
To explore this further, the researchers carried out experiments using animal models. They found that when they blocked these potassium channels, the drop in blood pressure did not happen.
This finding suggests that these channels play an important role in the side effect. It also opens the door to future treatments that could prevent this drop in blood pressure when IV acetaminophen is needed.
This research became especially important during the COVID-19 pandemic. During that time, IV acetaminophen was used more often in hospitals to manage pain and fever in seriously ill patients. Understanding its possible side effects can help doctors use it more safely in the future.
For people who take acetaminophen by mouth at home, there is no strong reason to worry. When used as directed, it remains a safe and effective medicine. The study mainly highlights the difference between taking a medicine by mouth and receiving it directly into the bloodstream.
For healthcare workers, this study is a useful reminder. It shows that even common medicines can behave differently depending on how they are given. Doctors and nurses should monitor patients carefully after giving IV acetaminophen so they can respond quickly if blood pressure drops.
This new knowledge can help improve patient care and safety. It also shows how ongoing research continues to reveal new details about medicines we thought we fully understood. Even simple and familiar drugs can have complex effects under certain conditions.
If you care about high blood pressure, please read studies about breakfast for better blood pressure management, and the gut feeling that lowers blood pressure.
For more health information, please see recent studies about how the dash diet helps lower blood pressure, and how to eat your way to healthy blood pressure.
The full study was published in the journal Atherosclerosis, Thrombosis, and Vascular Biology.
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