Acetaminophen: Safest Pill in the Medicine Cabinet, or is it?

OK, here is what you need to know about acetaminophen. First of all, I’m not going to tell you to quit taking acetaminophen. I am going to give you some information that you can use to make your own informed decision. This information should be of interest to 3 groups of people: unborn babies, children and adults. If you are in one of those groups, you should read this article.

I am not going to review the standard risks of liver damage, etc., that everybody is aware of. If you’re not aware of this, google it. Not hard to find. My focus is on the information you probably have NOT heard from your health care provider or pharmacist. The information you won't find on the label.

Acetaminophen is the generic name for Tylenol. But it also comes under a hundred other names such as Actifed®, Alka-Seltzer Plus®, Cepacol®, Contac®, Coricidin®, DayQuil®, Dimetapp®, Dristan®, Excedrin®, Feverall®, Formula 44®, Goody’s® Powders, Liquiprin®, Midol®, Mucinex®, NyQuil®, Panadol®, Robitussin®, Saint Joseph® Aspirin-Free, Singlet®, Sinutab®, Sudafed®, Theraflu®, Triaminic®, Vanquish®, Vicks®, etc. In England they call it paracetamol. It's included with Percocet and Vicodin.

Acetaminophen is ubiquitous, and hard to avoid. They estimate that 25% of Americans take acetaminophen in any given week. If you use Rx or OTC meds from the drugstore, you might be taking acetaminophen.

Concerns for Unborn Babies

Babies born to women that take acetaminophen while pregnant, have higher rates of ADHD and autism.

In 2014, a study in the journal JAMA Pediatrics said “Research data suggest that acetaminophen is a hormone disruptor, and abnormal hormonal exposures in pregnancy may influence fetal brain development.”

According to this 2014 study, acetaminophen use during pregnancy was associated with a 37% increased risk of the child being diagnosed with hyperkinetic disorder, a severe form of attention deficit hyperactivity disorder (ADHD).

Another study in 2016, also published by JAMA Pediatrics, reported use of acetaminophen at 18 through 32 weeks of pregnancy was associated with a 42% higher risk of conduct problems and a 31% higher risk of hyperactivity symptoms in the child. Mothers that used acetaminophen at 32 weeks of pregnancy, had a 29% higher rate of children with emotional problems and a 46% higher risk of “total difficulties.”

Both of the above studies were based on the mothers report of using acetaminophen. A study published in 2019, in JAMA Psychiatry achieved higher credibility by using cord blood tests for acetaminophen. The blood tests were considered more accurate than the mothers report.

Of the 996 babies in this study, those with the highest acetaminophen exposure had a 286% higher risk of ADHD and a 362% higher risk of autism or autism spectrum disorder.

Concerns for Children

Autism rates used to be low, about 4 per 10,000. The rate of autism increased in the 1980s, and is now about 100 per 10,000, which is quite an increase. Some have blamed that increase on greater awareness. IE, we’re looking for autism now, so we diagnose it more often.

But others point out that it was in the 1980s that we became aware of Reye’s syndrome, which is severe brain damage related to using aspirin. Since then aspirin has been banned for children, and parents and pediatricians, have been coached to use acetaminophen instead, the only FDA approved fever reducer for babies up through 6 months of age. Although we don’t have exact numbers, experts think 90%+ of children receive acetaminophen during their early developmental stages.

The journal Autism in May of 2008, reported on children given acetaminophen after their measles-mumps-rubella vaccination. Vaccines have been debunked as the cause of autism, but they found that:

“Acetaminophen use after measles-mumps-rubella vaccination was significantly associated with autistic disorder when considering children of 5 years of age or less.” (Emphasis mine)

This was a small study and it has been largely ignored. The same journal published another study in 2016 with older children that also presented evidence for the association of acetaminophen use with autism spectrum disorder.

A 2020 study of 1515 babies reported in Behavioral Science concluded that acetaminophen consumption before the age of 2 was "significant contributor to the risk of autism spectrum disorder among males in the US."

Concerns for Adults

In July of 2020 the Social Cognitive and Affective Neuroscience journal published an interesting study related to risk taking in adults. This study involved a couple of experiments.

Increased Risk Taking

In one experiment, some of them were given the standard dose of acetaminophen (1,000 mg), and the rest were given placebo. Using a computer they were given a chance to blow up a balloon. With each virtual puff of air they put into the balloon, they were rewarded with money. The bigger they filled the balloon the more money they got. But if they overfilled it and the balloon popped, they got no money. This was a test to see how much people were willing to risk to make more money. Those that were given the acetaminophen consistently risked more and popped more balloons than the people given the placebo.

In another experiment, participants were asked to rate how dangerous certain activities were on a scale of 1 to 7. They rated things such as bungee jumping, taking a skydiving class, or walking home late at night in an unsafe part of town. Those that took the acetaminophen rated these activities as less risky than those who took the placebo.

Risk taking is something each of us has to do. Weighing the relative risks vs the potential rewards is part of being an adult. It is frightening to think that our risk decision algorithm might change from week to week based on our use of an OTC medication.

Decreased Empathy

A study published in the same journal in 2016 looked at how acetaminophen influenced people's empathy. Using the same double blind, placebo controlled format, they had the participants read 8 short stories involving physical or emotional pain. They read about people losing a parent, or getting stabbed by a knife, etc. They were then asked to rate the pain these people experienced on a scale of 1 to 5. Those that took the acetaminophen rated the people's physical or emotional pain lower than those that took the placebo.

Other people in a second experiment, met and socialized with each other briefly. Each participant then watched, alone, an online game that involved three of the people they just met. In the game, two of the people excluded the third person from the activity.

Participants were then asked to rate how much pain and hurt feelings the excluded people in the game felt. The people that took the acetaminophen rated the pain and hurt feelings of the excluded person as less severe than the participants who took the placebo.

Empathy is the basis of pro-social and responsible behavior. Would the world be a kinder and gentler place without acetaminophen? We used to say. “Maybe he is just a jerk.” Now we might say, “Maybe that’s just the acetaminophen talking.”

Let’s Look at the Big Picture

Association doesn't prove causation and this is still preliminary data, but ADHD and autism can be pretty serious, so mothers may want to avoid acetaminophen for now, until it is proven safe.

Plenty of other drugs are banned during pregnancy. No amount of alcohol is considered safe during pregnancy or nursing. If this information about acetaminophen is not proven false, acetaminophen will also be banned during pregnancy and nursing.

But the information about adults is just creepy. Some adults don't mind taking mind altering drugs, but they want to know when they are taking one. I don't want to wake up one day and have this conversation:

ME: "Look at how much money I lost in this stupid investment. What was I thinking?"

WIFE: "You took 2 Tylenol tablets for a headache, and underestimated the risk."

On another day:

ME: "How did I not realize I would break my leg doing that?"

WIFE: same answer

Or unwed teenagers having this conversation:

BOY: "I forgot to bring the condom."

GIRL: "Who cares, what's the chances I'll actually get pregnant?"

Or the President of the United States:

President: "I think I am going to sink their ship. They've been warned."

Secretary of State: "Yeah, what can they do about it?"

(World War 3 starts the next day.)

Conclusion

Acetaminophen is associated with increased ADHD and autism in children.

Adults appear to underestimate risks and have less empathy for others when using acetaminophen.

Now you can make an informed decision. I would love to get your feedback in the comments.

P.S. Don't take acetaminophen before making your decision!