Acetaminophen is the most common drug ingredient in America. You’ll find it in more than 600 over-the-counter and prescription medications. Research suggests this popular analgesic may come with a price to our health. Find out what I wish I had known about Tylenol.
When my kids were young, doctors prescribed Tylenol readily, encouraging us to alternate with ibuprofen when needed. I didn’t think twice about this until our health crisis in 2008. (Read our story here.) I learned to ask questions about every aspect of medical care, including over-the-counter remedies like Tylenol.
What is Acetaminophen?
Acetaminophen, also known as paracetamol or APAP, is a medication used to treat pain and fever. The trademark Tylenol comes from the chemical term N-aceTYL-p-aminophENOL.
Acetaminophen is derived from coal tar and is the only coal tar medication on the market today. Phenacetin, also derived from coal tar, was banned by the FDA in 1983. Coal tar contains more than 10,000 chemicals. Once derived from coal, coal tar is now more commonly derived from petroleum. Coal tar mixtures are classified as a Group 1 carcinogen by the World Health Organization.
How does Tylenol work?
Acetaminophen appears to work by inhibiting the synthesis of prostaglandins in the central nervous system. Prostaglandins serve some protective functions in the body, but they can also produce pain and fever. Acetaminophen differs from other pain relievers in that it doesn’t possess anti-inflammatory properties. Its appeal stems from its gentleness on the stomach and intestinal lining as opposed to ibuprofen or aspirin.
It is now widely known that while acetaminophen may help reduce pain or fever, it also depletes glutathione, a key player when it comes to detoxification in the body.
The Toxicity of Acetaminophen
Too much acetaminophen can damage or destroy the liver. According to the Food and Drug Administration, exceeding the maximum recommended dose of acetaminophen (four thousand milligrams per day) can cause serious liver injury—even death. Acetaminophen overdose is one of the most common poisonings worldwide. The FDA estimates that overdoses were linked to 56,000 emergency room visits, 26,000 hospitalizations, and 458 deaths from 1990-1998. According to FDA findings, overdoses occur because:
Consumers may attempt to treat different conditions or symptoms at the same time with more than one product containing acetaminophen. They may not realize that acetaminophen is in each of those products and that they are at risk of acetaminophen overdose.
With more than 600 prescription and over-the-counter medications containing acetaminophen, it’s easy to imagine that consumers can unknowingly overdose. Examples of OTC medications that contain acetaminophen include:
- Alka-Seltzer Plus Liquid Gels
The Liver Foundation’s Acetaminophen Awareness Coalition lists more medications in the article Common Medicines with Acetaminophen. The chart below lists common forms of acetaminophen and dosages.
What Do the Studies Show?
Not only does acetaminophen have known toxicity, it is also now known that it crosses the placenta and blood-brain barrier. Acetaminophen has been associated with:
- Failure of neural development
- Male infertility in offspring
- Behavioral problems in offspring
- Poor gross motor development
- Language delays in girls (study here)
(Specific studies may be found in the article Acetaminophen: Old Drug, New Issues.)
What’s more, recent evidence suggests that acetaminophen is a hormone disruptor (i.e., it interferes with reproductive and thyroid hormone function—see this relevant study) and may trigger wheezing or asthma in the offspring of mothers who take acetaminophen during pregnancy (relevant study here).
One of the most stunning studies to date involved close to 50,000 pregnant women in Norway. The 2013 cohort study found that:
Children exposed to prenatal paracetamol for more than 28 days had poorer gross motor development, communication, externalizing behavior, internalizing behavior, and higher activity levels . . . Ibuprofen exposure was not associated with neurodevelopmental outcomes.
Studies also link autism spectrum disorder with acetaminophen use during pregnancy.
- Maternal Use of Acetaminophen during Pregnancy and Risk of Autism Spectrum Disorders in Childhood: A Danish National Birth Cohort Study
- Prenatal and Perinatal Analgesic Exposure and Autism: An Ecological Link
- Prenatal exposure to acetaminophen may increase autism spectrum and hyperactivity symptoms in children
A 2016 study found that acetaminophen may dull not just our pain but also our empathy. In two double-blind placebo-controlled experiments, participants rated perceived pain, personal distress, and empathetic concern after reading stories with sad scenarios.
As hypothesized, acetaminophen reduced empathy in response to others’ pain. Acetaminophen also reduced the unpleasantness of noise blasts delivered to the participant, which mediated acetaminophen’s effects on empathy. Together, these findings suggest that the physical painkiller acetaminophen reduces empathy for pain and provide a new perspective on the neurochemical bases of empathy.
I wish I had known all of this when my kids were young. All I can do now is use my knowledge to propel me forward. For now, I’ll keep acetaminophen out of our medicine cabinet, stick with ibuprofen when necessary, and continue to explore natural pain remedies when the need arises.
Dr. Ann Bauer specializes in the developmental effects of analgesics, with a particular emphasis on acetaminophen. In this episode of The Connecting Place, Dr. Bauer shares how one conversation over lunch turned the course of her career.