Acetaminophen is usually tolerated well by patients and is considered safe enough to be sold over-the-counter. It can be easily combined with other medications such as prescription opioids to maximize pain relief and over-the-counter cold and flu preparations. Acetaminophen may also be used in some stomach relief medications and combined with sleep aides (Tylenol PM, for example).
Because so many medications can contain acetaminophen, it is important to know that acetaminophen has a maximum dose of 4 grams per 24 hours for healthy adults. For adults with impaired liver function, that dose is even lower. Four grams is equivalent to 12 tablet of regular strength acetaminophen (325mg tabs). Because a usual dose is 650 mg, that is 6 doses per day. For extra strength tablets (500mg), the maximum dose would be 8 tablets per day.
To illustrate how an overdose can occur, let’s say a person is told to by their doctor that they can take 650mg of Tylenol every 4-6 hours for pain, which they do. They are also taking a cold preparation containing 500mg of acetaminophen for a cough every 4 hours but have not informed the doctor of this. They are well exceeding the maximum daily dose of acetaminophen and risking permanent liver damage.
Being diligent in reading labels on medications can help prevent an overdose. Any medication that contains acetaminophen must list it in the active ingredients. And, of course, always tell your doctor or nurse about any over-the-counter medications you are taking.
Alcohol can increase the risk of liver damage and damage to the lining of the stomach. The risk is greatest with heavy alcohol use. Occasional or moderate use of alcohol is usually tolerated with acetaminophen but you should always discuss this with your doctor.