MONDAY, Nov. 4 (HealthDay News) -- Combining acetaminophen pain relievers, which include Tylenol, and even light amounts of alcohol can more than double the risk of kidney disease, new research suggests.
Taking the recommended dose of acetaminophen, combined with a small to moderate amount of alcohol, produces a 123 percent increased risk of kidney disease, according to a new preliminary study.
"Most people take this medication without any input from pharmacists or physicians, and that's where the public-health concern is," said lead researcher Harrison Ndetan, an associate professor for research and biostatistics at Parker University in Dallas. "People buy acetaminophen over the counter, and they also are casual alcohol users, and they don't know that there is a harmful interaction."
The study, scheduled for presentation Monday at the American Public Health Association's annual meeting in Boston, establishes only an association between an acetaminophen-and-alcohol combination and increased risk for kidney disease, not a direct cause-and-effect relationship.
Chronic acetaminophen use and chronic alcohol abuse both have been separately linked to kidney and liver disease, said Dr. Martin Zand, medical director of the kidney and pancreas transplant programs at the University of Rochester Medical Center in New York.
"What has not been well-studied until now is the link between some regular alcohol use and regular acetaminophen use and increasing your risk of kidney disease above the risk of either of those used separately," said Zand, who was not involved in the new research.
For the study, researchers analyzed data from more than 10,000 people who participated in the 2003-04 U.S. National Health and Nutrition Examination Survey. It included questions about alcohol consumption, use of acetaminophen and health problems.
The study found that neither normal use of acetaminophen nor light to moderate drinking posed a potential threat to kidneys.
Nearly half of the people who combined the two, however, reported health problems related to their kidneys, the researchers said. Specifically, of the 2.6 percent who took the combination, 1.2 percent reported kidney dysfunction.
Alcohol can interfere with the gene that regulates the way the body processes acetaminophen, Ndetan said, adding that this is the most likely potential explanation for the association found in the study.
The warning label included on acetaminophen packaging does say not to take the medication with alcohol, Ndetan said, "but it is important for people to receive this message because people will take them despite those warnings."
It's not known if similar interactions occur with other painkillers, he said.
In general, people who regularly consume one should not use the other, Zand said.
If you take acetaminophen daily for chronic pain, you should avoid alcohol, he said. If you drink alcohol regularly, you should try another painkiller or avoid over-the-counter pain medications altogether.
"I'm not suggesting people should not use acetaminophen and should not appropriately and modestly consume alcohol," Zand said. "But it's not a good idea to take acetaminophen for a number of days in a row and then drink alcohol."
So what about taking acetaminophen for a hangover?
"If you do need to take something for pain and if you are not a regular drinker, it would seem to be OK to take some acetaminophen for it," Zand said. "Assuming your kidneys are fine, you might want to choose another painkiller if you want to err on the side of caution, because you've just put your liver through a stress test and it needs all the breathing room it can get to recover."
Research presented at meetings is typically considered preliminary until published in a peer-reviewed medical journal.
For more information on acetaminophen toxicity, visit the U.S. Food and Drug Administration.
SOURCES: Harrison Ndetan, associate professor for research and biostatistics, Parker University, Dallas; Martin Zand, M.D., professor of medicine and medical humanities, and medical director, kidney and pancreas transplant programs, University of Rochester Medical Center, Rochester, N.Y.; abstract, American Public Health Association, annual meeting, Boston, Nov. 4, 2013