Brand name Tylenol, acetaminophen is a synthesized substantive for aspirin that has the benefits of relieving pain and lowering fever, but without the side effects of preventing clotting or causing gastrointestinal side effects. Available over-the-counter in many types of medications including cold remedies, headache medications and fever medications, Tylenol can be dangerous, sometimes causing liver damage, when taken in high doses for prolonged periods of time. Patients should generally avoid taking more than 2 or 3 grams total of Tylenol per day. Tylenol, useful for what is termed minor pain, has been shown effective for more serious conditions such as the pain associated with osteoarthritis of the hip or knee. Many narcotic pain medications are manufactured in combination with Tylenol, such as Tylenol with Codeine, Vicodin, Percocet, Norco and others.