WebMD says that it is okay to take Tylenol and Sudafed at the same time. But some drugs combine pseudoephedrine and acetaminophen, which are both found in Tylenol. If this is the case, you shouldn’t take any more Sudafed or Tylenol to avoid taking too much.
CVS Pharmacy says that acetaminophen is a common pain reliever that is also found in many over-the-counter medicines, such as Theraflu and NyQuil. Acetaminophen is also in painkillers like Vicodin and Percocet that you have to get from your doctor.
Too much acetaminophen can hurt the liver, cause it to stop working, or even kill you, CVS said, citing FDA studies. Studies show that almost half of people with liver failure have taken too much acetaminophen, which causes more than 450 deaths every year.