Does acetaminophen reduce empathy?

May 13, 2016 Providence Health Team

A new study suggests that when you take acetaminophen to reduce physical pain, you also may feel less emotional pain—or empathy—for others.

Researchers at The Ohio State University who conducted the study say their findings provide a new perspective on neurochemicals in the brain and how they regulate emotions such as empathy, which influences positive and antisocial behavior. They also say the results “raise concerns about the broader social side effects of acetaminophen, which is taken by almost a quarter of US adults each week.”

Most people probably think of Tylenol, Anacin 3 or Percocet when they think of acetaminophen, but the painkiller is found in more than 600 pain medications.

Three experiments, similar outcomes

Led by Dominik Mischkowski, formerly a Ph.D. student and now at the National Institutes of Health, the research team conducted three experiments. In the first, they divided 80 college students into two groups. Half of the students drank a liquid containing the equivalent of two extra-strength Tylenol tablets. The other students consumed a placebo drink.

After waiting an hour for the painkiller to take effect, the researchers asked each participant to read eight short stories about someone experiencing pain. They included a story about a person suffering a deep knife wound and another about the loss of a loved one. The students were asked to rate the pain of the characters in the stories on a scale of 1 to 5, with 5 being the worst pain. Those who drank the acetaminophen concoction rated the pain of the characters as less than the placebo group.

Next, the researchers divided 114 students into two groups and again gave half an acetaminophen drink and the others a placebo. All were subjected to “painful noise blasts” that compared to the decibel levels of a train whistle, snowmobile and motorcycle.

This time, the pain scale was 1 to 10, with 10 being very unpleasant. The students were asked two questions:

  • How they personally experienced the blasts
  • How they thought an anonymous study participant would rate the blasts

The acetaminophen group rated each of these scenarios as less unpleasant than the placebo group.

Finally, the scientists created a scenario in which two participants excluded a third from an activity. Those who witnessed the exclusion didn’t know it was a simulation. Similar results: Those who took acetaminophen rated the pain of the excluded person as lower than the students who took a placebo.

Drawing conclusions

While acetaminophen appeared to make some participants less empathetic, the scientists noted that the painkiller didn’t erase all empathy and they characterized the drug’s effects more along the lines of moderate. They said more research needs to be done to understand the link between acetaminophen and empathy. They believe neurochemicals might hold the key.

How to take acetaminophen safely

Acetaminophen can cause liver damage when more is taken than directed, according to the Food and Drug Administration.

The National Institutes of Health offers some advice on taking acetaminophen safely.

  • Take acetaminophen exactly as directly on the prescription or package label.
  • Do not take more than one product that contains acetaminophen at a time. Read the labels of all prescription and nonprescription medications to see if they contain the drug. Sometimes acetaminophen is abbreviated as AC, ACetaminoph, Acetaminop, Acetamin or ACetam.
  • Don’t take more than 4,000 mg of acetaminophen a day. If you're taking more than one product that contains the painkiller, talk to your doctor.
  • If you have had liver disease, talk to your doctor before taking the medication.
  • Do not take acetaminophen if you drink three or more alcoholic drinks a day.

If you have any questions or concerns about taking acetaminophen, talk with your pharmacist or health care provider. You can find a Providence provider here.

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