Navigation Links
Caffeine Plus Acetaminophen Toxic for Some

Rat study suggests liver danger, but doses must be very high

WEDNESDAY, Sept. 26 (HealthDay News) -- Very high doses of caffeine and acetaminophen (such as Tylenol), taken together, could lead to liver damage, researchers warn.

This combo produces a byproduct enzyme that's toxic to the organ, researchers from the University of Washington report.

This toxic twosome can occur not only by drinking caffeine while taking acetaminophen, the experts added, but also from large doses of painkillers that combine caffeine and acetaminophen. These painkillers are often used to treat migraines, menstrual discomfort and other conditions.

"Caffeine can interact with an enzyme that can form a toxic metabolite of acetaminophen in such a way that it increases the formation of that toxic metabolite," said lead researcher Sid Nelson, a professor of medicinal chemistry. "This can result in liver damage," he said.

In the study, Nelson's team tested the effects of acetaminophen and caffeine on E. coli bacteria. These bacteria had been genetically engineered to mimic a human enzyme in the liver that detoxifies many prescription and nonprescription drugs, explained the authors in a report in the Oct. 15 issue of the journal Chemical Research in Toxicology.

Nelson noted that it takes large qualities of caffeine to produce this reaction.

"Normally people wouldn't be ingesting that amount of caffeine," he said. "It would take 10 times the amount of caffeine found in a couple of cups of coffee," Nelson said.

His team found that caffeine triples the amount of a toxin called N-acetyl-p-benzoquinone imine (NAPQI) produced by the enzyme as it breaks down acetaminophen.

This same toxin is also produced during an interaction between alcohol and acetaminophen that's also well known to damage the liver.

In prior studies, Nelson's team had found that high doses of caffeine boosted liver damage in rats that had already suffered acetaminophen-linked liver damage.

The bacteria used in the study were exposed to doses of acetaminophen and caffeine far higher than most people would be exposed to, Nelson noted. It's not clear at what point such a mixture becomes toxic, he said.

Some people may be more vulnerable to this toxic interaction than others, Nelson said. They might include people who take certain antiepileptic medications, such as carbamazepine and phenobarbital, and people who use the alternative remedy St. John's Wort.

These drugs increase levels of the enzyme that produces NAPQI and may produce even more when mixed with acetaminophen and caffeine together, Nelson speculated.

In addition, because alcohol can boost NAPQI production, people who drink a lot may be at increased risk for this toxic interaction, the researcher said. The risk is also increased for people who take drugs that combine acetaminophen and caffeine, used to treat migraines, arthritis and other conditions.

Still, for most people, there's no reason to panic, since the chances of caffeine and acetaminophen becoming a toxic mixture remains small, Nelson said.

"Almost all people don't need to worry about taking caffeine with acetaminophen," Nelson said. Exceptions might be, " those [people] taking high does of caffeine, high doses of acetaminophen, who are possibly alcoholic and/or are epileptic and take certain anticonvulsive drugs," he said.

More information

For more on acetaminophen, visit the U.S. National Library of Medicine.

SOURCES: Sid Nelson, Ph.D., professor, medicinal chemistry, University of Washington, Seattle; Oct. 15, 2007, Chemical Research in Toxicology

Copyright©2007 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Caffeine Found To Worsen Diabetes
2. Caffeine keeps soldiers sharp
3. Caffeine can induce epilepsy in newborns
4. Caffeine reduces infant blood flow
5. Caffeine fights Gallstones
6. Caffeine is not the only culprit in coffee!
7. Caffeine Intake May reduce Insulin Sensitivity
8. Research unearths how caffeine prevents us from sleeping
9. Caffeine can interfere with PET scan results
10. The Link Between Caffeine Drinks And Obesity
11. Caffeine Boosts Memory, Improves Attention Span
Post Your Comments:
(Date:11/26/2015)... ... November 26, 2015 , ... Pixel Film ... trailer titles with ProTrailer: Vintage. This newly styled ProTrailer pack comes with 30 ... with any font, giving users limitless opportunities to stylize and create designs quickly ...
(Date:11/25/2015)... ... , ... The holiday season is jam-packed with family dinners, ... attendees is of the utmost importance. Whether you are cooking at home for ... a try this holiday season. , Turkey Croquettes ,     Ingredients: , ...
(Date:11/25/2015)... ... November 26, 2015 , ... Ministers, senior ... (EU), ANDI Pan African Centres of Excellence, and public R&D institutions, civil societies ... the opening of the 5th African Network for Drugs and Diagnostics Innovation, ANDI, ...
(Date:11/25/2015)... ... 2015 , ... Dental professionals who would like to become more proficient on ... Dr. Mark Iacobelli’s Advanced Implant Mentoring (AIM) CE course. Courses will be held on ... co-founders of Advanced Implant Mentoring (AIM), Dr. Iacobelli and Dr. D’Orazio are proud to ...
(Date:11/25/2015)... ... ... Smiles by Stevens is pleased to announce the addition of ... patients are aware of the benefits of Botox® in the treatment of moderate facial ... discomfort, soreness, and pain as a result of Jaw Tension, TMJ (temporo-mandibular joint) disorder, ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... 2015 Kitov Pharma ceuticals ... a biopharmaceutical company focused on the development of therapeutic ... today announced the closing of its previously announced underwritten ... ), each representing 20 ordinary shares of the Company, ... ADSs and warrants were issued in a fixed combination ...
(Date:11/25/2015)... the issue of United States patent No. 9,192,509  entitled: " Methods and ... company,s AVACEN 100 dry heat therapy medical device and specific methods of use, referred to by ... Photo - ... ... ...
(Date:11/25/2015)... 25, 2015 USP 800 applies to ... (e.g. pharmacists, pharmacy technicians, nurses, physicians, physician assistants, ... chapter also covers all entities which store, prepare, ... other healthcare institutions, patient treatment clinics, physicians, practice ... --> What is the purpose ...
Breaking Medicine Technology: