USMLE Step 2 CK Question of the Day: Altered Mental State After Over the counter pain reliever and Prescription Hydrocodone acetaminophen Osmosis Blog Is Tylenol Safe During Pregnancy? Understanding Risk Factors Seeking Health Acetaminophen, also known as Tylenol, is used to help with pain & to reduce fever. However, taking too much acetaminophen can be harmful to the liver which filters out toxins & Early life acetaminophen exposure, glutathione S transferase genes, and development of adolescent asthma in a high risk birth cohort Journal of Allergy and Clinical Immunology