Acetaminophen - also known as Tylenol and paracetamol Drugs.com Acetaminophen (Tylenol, Extra-Strength Tylenol, generics) is a safe choice, and is often one of the first treatment choices in osteoarthritis. However, acetaminophen can be toxic to the liver when used in excessive doses. It is important to read the labels on bottles of acetaminophen to be sure you do not exceed recommended doses. In addition, if you are using the maximum dose of acetaminophen, be sure to avoid other products that also contain acetaminophen, such as over-the-counter (OTC) cold remedies, combination pain pills such as Benadryl, acetaminophen/hydrocodone (Lortab, Vicodin), and many other products. Be wary of Tylenol PM as it has 650mg acetaminophen Maximum intake per 24hrs recently recommended by the FDA is a limit of 3,000mg due to people not taking care that other medications they are taking also have acetaminophen in them. Assuming this is not the case and that you stay vigilant with OTC meds, then a maximum of 4,000mg is safe.