Cold, cough, and flu season is a good time to revisit the risks of acetaminophen the pain and fever reliever in Tylenol and many other over-the-counter medications. Billions of doses of acetaminophen are consumed safely every year, but deaths still occur from accidental overdoses and thousands of people end up in the emergency room. More than 600 products contain acetaminophen, and inadvertently combining them can nudge you into the red zone.

People don't realize that these doses all add up, and before you know it you've exceeded the recommended dose of acetaminophen.

Acetaminophen controls pain and fever but does not reduce inflammation, as doesaspirinand the other widely consumed nonsteroidal anti-inflammatory drugs (NSAIDs) ibuprofen (Advil, Motrin, generics) and naproxen (Aleve, generics). But unlike NSAIDs, acetaminophen does not irritate the stomach and intestinal lining. That means a person who cannot tolerate NSAIDs can still take acetaminophen. It's an important drug for controlling chronic pain in older adults.

The hitch is that acetaminophen also has a narrower window of safety compared with ibuprofen and naproxen. NSAIDs can make you sick, too, but it takes a larger amount to reach a dangerous overdose. Taking too much acetaminophen can damage the liver, sometimes leading to a liver transplant or death.

The body breaks down most of the acetaminophen in a normal dose and eliminates it in the urine. But some of the drug is converted into a byproduct that is toxic to the liver. If you take too much all at once or over a period of daysmore toxin can build up than the body can handle.

For the average healthy adult, the absolute maximum daily dose is no more than 4,000 milligrams (mg) from all sources. But in some people, doses close to the 4,000 mg daily limit for adults could still be toxic to the liver. It's safest to take only what you need, and to not exceed 3,000 mg a day whenever possible, especially if you use acetaminophen often.

If you ever have concerns about how much acetaminophen you can tolerate based on your age, body size, and health status, talk to your doctor or pharmacist. Here are some general precautions for avoiding an accidental overdose of acetaminophen.

Tens of thousands of people become ill every year from taking too much acetaminophen. In a smaller number of casesseveral hundred per year it leads to death. But it need not happen to you. Read the labels in all your over-the-counter and prescription drugs to look at the specific amounts of acetaminophen in each, and stick to the guidelines.

325 mg

500 mg

650 mg extended release

Take how many pills at a time?

1 or 2

1 or 2

1

Take how often?

Every 4 to 6 hours

Every 6to 8hours

Every 8 hours

Safest maximum daily dose

for most adults

8 pills

6 pills

4 pills

Never take more than this in a 24-hour period

12 pills (3900 mg)

8 pills (4000 mg)

6 pills (3900 mg)

It's best to take the lowest dose necessary and stay closer to 3,000 mg per day as your maximum dose. If you need to take high doses of acetaminophen for chronic pain, check with your doctor first.

For therapy options beyond the standard approaches to managing pain, buy the Harvard Special Health ReportPain Relief Without Drugs or Surgery .

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Excerpt from:
Acetaminophen safety: Be cautious but not afraid - Harvard Health