RELATED: This Is When You Should Take Tylenol Instead of Advil, Doctors Say. A 2007 study published in the journal Chemical Research in Toxicology found that consuming large amounts of caffeine while taking Tylenol, generically known as acetaminophen, could potentially cause liver damage. By testing the simultaneous effects of acetaminophen and caffeine on genetically engineered E. coli bacteria, the researchers found that caffeine triples the amount of a toxic byproduct called N-acetyl-p-benzoquinone imine (NAPQI) that a key enzyme in the liver produces while breaking down acetaminophen. It’s the same toxic byproduct that results in liver damage and liver failure when combining alcohol and Tylenol, according to the researchers. “People should be informed about this potentially harmful interaction,” Sid Nelson, PhD, a chemist who led a team of researchers for the study, said in a statement. According to Nelson, some people may need to exercise more caution than others when it comes to Tylenol and caffeine. This includes people who taken anti-epileptic medications like arbamazepine and phenobarbital, and those who use the herbal supplement St. John’s Wort. Both these additional pills have been shown to increase levels of the enzyme that produces the liver-damaging toxin, Nelson says.ae0fcc31ae342fd3a1346ebb1f342fcb The risk is also higher for people who drink a lot of alcohol and those who already take large amounts of medications that combine acetaminophen and caffeine. RELATED: For more up-to-date information, sign up for our daily newsletter. Caffeine can increase the potency of acetaminophen, too, according to Everyday Health. There’s even a product called Tylenol Ultra Relief that’s a combination of caffeine and acetaminophen in low doses. (Another similar product on the market is Excedrin Tension Headache.) Additional caffeine from coffee, tea, soft drinks, and energy drinks should also be avoided when taking this kind of Tylenol because it can increase your chances of having negative side effects. According to Everyday Health, common side effects of this medication include sleep problems, nervousness, irritability, or jitteriness. But if you experience a low-grade fever with nausea, stomach pain, loss of appetite, dark urine, clay-colored stools, or jaundice, you should contact your doctor immediately and stop using any Tylenol products, as these are all symptoms of liver damage. You don’t have to stop consuming caffeine altogether if you’re using Tylenol, but you should never ingest large amounts of it with the pills. According to the Mayo Clinic, you should only have up to 400 milligrams of caffeine every day, which is about four cups of coffee, 10 cans of soda, and two energy shot drinks. And the recommended daily dosage of Tylenol is no more than 4,000 milligrams, which is about eight pills. “The bottom line is that you don’t have to stop taking acetaminophen or stop taking caffeine products, but you do need to monitor your intake more carefully when taking them together, especially if you drink alcohol,” Nelson warned. RELATED: Don’t Use Mouthwash If You’re Taking These 2 Medications, Experts Warn.
