Acetaminophen, sold under the brand name Tylenol and also included in more than 200 over-the-counter cold and flu remedies and other medications, is the most widely used painkiller in the United States. Up to 100 million Americans take acetaminophen every year.
While most people assume Tylenol and other over-the-counter medications that contain acetaminophen are harmless, the drugs are actually surrounded by a growing controversy as to their safety — even when taken at the recommended dosages.
Liver Damage Possible Even at Recommended Doses
It’s well known that overdosing on Tylenol (which is commonly done accidentally, as we discuss below) can harm the liver. However, a study published in the Journal of the American Medical Association found that even at recommended doses, the drug shows signs of causing organ damage.
Out of 106 patients in the study, 41 of them (39 percent) who took acetaminophen alone (Extra Strength Tylenol) or in combination with another drug had their liver enzymes increase to more than three times the normal upper limit. It is at this threshold (when liver enzymes increase to three times the normal level) that doctors typically become concerned about potential liver damage.
Further, another 27 patients had enzyme levels increase more than five times normal, and eight patients had levels that increased eight times the normal enzyme level. Their enzyme levels continued to increase for up to four days after the acetaminophen was stopped, and their enzyme levels did not return to normal for as long as 11 days, researchers said.
“This study shows that even taking the amount on the package can be a problem for some people,” said Dr. William M. Lee of the University of Texas Southwestern Medical School, who was not involved in the study.
Long-Term Tylenol Use May Damage the Kidneys
A study published in the Archives of Internal Medicine found that 10 percent of women who took acetaminophen over an 11-year period had a 30 percent decline in kidney filtration function.
The more acetaminophen taken, the greater the damaging effects. Among women who took between 1,500 and 9,000 tablets during the study, risk of kidney impairment increased 64 percent. Those who took more than 9,000 tablets had an even greater risk.
Further, an article in Life Extension magazine points out that several studies have shown that regular use of acetaminophen may double your risk of kidney cancer.
Accidental and Intentional Overdosing Common
Acetaminophen overdose is the leading cause of acute liver failure in the United States. While some of these stem from intentional overdoses (England has placed restrictions on the number of acetaminophen pills that can be sold at one time due to suicide concerns), many are accidental.
In fact, each year more than 56,000 people visit an emergency room because of acetaminophen overdoses, and 100 people die from unintentionally taking too much.
When taken at the highest recommended dose, experts say acetaminophen is generally safe, but acknowledge that the margin of error is very small.
According to Lee, the maximum dose of many acetaminophen medications, including Extra Strength Tylenol, is set too high. In the case of Extra Strength Tylenol, the maximum dose is two 500-milligram pills every six hours, or 4 grams a day.
If a person inadvertently takes an extra pill, an extra dose, or a different medication that may also contain acetaminophen (it’s also in the prescription narcotics Vicodin, Percocet, and others), they can easily surpass the upper limit and put themselves at risk of liver damage, liver failure and even death.
“Just a doubling of the maximum daily dose can be enough to kill,” says Dr. Anne Larson of the University of Washington Medical Center. And ” … if two is good, 10 is better in some patients’ minds,” she says.
Adding to the problem is the sheer number of products available that contain acetaminophen.
“You can take a prescription med that has acetaminophen in it, and a cough syrup that has acetaminophen in it, and then if you take an Extra-Strength Tylenol, you can have 4 grams of acetaminophen,” says Matthew Grissinger, a pharmacist and medication-safety analyst for the Institute for Safe Medication Practices. “There’s too much choice out there. It’s out of hand.”
