New Evidence Suggests Trouble With Tylenol

May 12, 2016

Tylenol is one of the most widely used painkillers across the United States. Its main ingredient, acetaminophen, is present in more than 600 over-the-counter and prescription medications. But several recent studies are bringing up new concerns about this familiar drug.

Stacie McDonald is bouncing her fussy baby while trying to find something to occupy her 5-year-old. She tells me she gets headaches twice a week and migraines almost every month.

“I have visual disturbances like tunnel vision,” she says. “I also get numbness in my hands and my face. And then pretty soon after that, within an hour at least, is nausea, and then the really intense pain.”

McDonald is a stay at home mom of two. She lives in Phoenix, Oregon. She says the pain is excruciating.

“Like if someone put your head in a vice grips and tightened it really tight so it was really contracted and let it go all at once, so it’s like this pulsating, this really intense pulsating pain,” she says.

Like millions of other Americans, McDonald finds some relief from Tylenol. But though Tylenol is a go-to drug, evidence is accumulating that it may not be as safe as people think.

Daniel Randles is a post-doctoral fellow at the University of Toronto.

“Acetaminophen has effects that we don’t normally associate with it,” he says. “Some labs have found that it reduces feelings of social rejection or social frustration. We found that it reduces reactions to uncertainty. Some people have even found that it … makes it harder to feel really strongly about things.”

Randles is the lead author on a new study published in the peer-reviewed journal Social Cognitive and Affective Neuroscience.

His team gave some participants acetaminophen and others a placebo. The participants were then given a task—to hit a button every time they saw the letter “F” but not when they saw the letter “E” —and their brain waves were recorded. Participants who had taken acetaminophen not only made more mistakes, their brains were less able to perceive that mistakes had been made.

“We have reasonably good evidence from this study to suggest that acetaminophen is inhibiting some ability to actually perceive or detect errors.”

On its own this small study might not be that remarkable. But it’s part of a growing body of scientific evidence suggesting acetaminophen has negative effects on the brain.

When Norwegian researchers examined the health outcomes of 48,000 children, they found that children of women who had taken acetaminophen during pregnancy were 70 percent more likely to have developmental delays and brain abnormalities than children whose mothers didn’t take the drug.

In a Danish study, researchers tracked over 64,000 children. Children whose mothers used acetaminophen during pregnancy were at higher risk for attention disorders. The more often moms used the drug, the more severe the problems in their children.

In a just-released study, researchers at the University of Texas medical school found that the pediatric use of Tylenol is associated with childhood autism.

McNeil Consumer Healthcare – makers of Tylenol – dispute these findings. In a written statement, they say none of the current studies show “a causal link between acetaminophen use during pregnancy or in childhood and adverse effects on child development, including autism.”

Federal authorities are also not convinced. In January the Food and Drug Administration said that the medical evidence is, quote, “too limited to make any recommendations based on these studies at this time,” but pregnant women should, quote, “consult with their health care professional before taking any prescription or OTC medication.”

That’s what Stacie McDonald did when she got pregnant for the first time. She used to take Tylenol for every headache. But her midwives told her to avoid it. These days when she feels a migraine coming on, McDonald tries other remedies first:

“Turn lights off, try to get away from the sunlight, because a lot of times light and loud noises and stuff can make it worse. And if that doesn’t work I will try, you know, caffeine , a cup of coffee or some black tea. And if that doesn’t work I turn the TV on for the kids to be distracted and try to lay down.”

Steven Wells thinks McDonald has the right idea. Wells is a family physician in Phoenix, and has been practicing medicine for 25 years. He notes that the Centers for Disease Control and Prevention is now encouraging doctors to recommend non-pharmaceutical treatments for ongoing pain.

“There is really good evidence that non-medication treatments are at least as effective as medications: ice, massage, stretching, aerobic exercise, mindfulness, yoga, all those wonderful things,” he says.

We tend to think of Tylenol as safe because it’s so widely used. But that assumption may be wrong.

“I do not believe that it is safe to assume that because something is used a lot it is safe,” says Dr. Wells. “There are many other effective treatments besides medications and it makes sense to do the least toxic thing, the healthiest lifestyle thing you can.

The jury’s still out on Tylenol. Until we know more, Wells says, it’s best to proceed with caution.