A new study conducted in mice found that the common painkiller acetaminophen changes proteins in heart tissue when used regularly in moderate doses. The researchers are scheduled to present their findings this week at the American Physiological Society (APS)’s major annual meeting, the American Physiological Summit, in Long Beach, California.

We found that regular use of acetaminophen at concentrations considered safe (equivalent to 500 mg per day) alters numerous signaling pathways within the heart. These results led me to consider using acetaminophen at the lowest effective dose and for the shortest possible time. ”

Gabriela Rivera, lead author of the study

Gabriela Rivera is a PhD student working in the lab of Dr. Aldrin Gomez at the University of California, Davis.

Acetaminophen, the active ingredient in Tylenol and many other painkillers, is generally considered to have a low risk of harmful side effects when used as directed. It is often recommended over nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen for people with high blood pressure or heart disease.

In the past, studies examining the possible effects of acetaminophen on the heart have yielded mixed results. However, Rivera said previous studies have shown that regular use of acetaminophen in high doses is more likely to cause heart disease than occasional use and low doses. It has been consistently suggested that

Observing the levels of various proteins in tissues is a common way for scientists to assess how well the body is performing its normal functions. Rivera and colleagues in the Gomez lab used mice to study how acetaminophen affects protein balance in the heart. Some mice were given plain water, while others were given water containing an amount of acetaminophen equivalent to 500 milligrams per day for an adult (the amount found in one extra-strength Tylenol tablet).

After seven days, mice given acetaminophen showed significant changes in the levels of proteins involved in biochemical pathways involved in a variety of functions, including energy production, antioxidant use, and the breakdown of damaged proteins. .

“We expected a few pathways to change, but we found that more than 20 different signaling pathways were affected,” Rivera said.

The results suggest that long-term use of moderate to high doses of acetaminophen may cause cardiac problems as a result of oxidative stress and the accumulation of toxins produced during acetaminophen breakdown. Rivera said. Our bodies are usually able to eliminate such toxins before they cause damage, but consistently consuming moderate to high doses over long periods of time can make it difficult for the body to catch up. there is.

One caveat, Rivera noted, is that the study was done in mice, so it can’t necessarily be extrapolated to humans. The researchers suggested aiming to limit continuous acetaminophen use to a few days and discussing concerns about using high doses of acetaminophen with your health care provider.