Are You Taking Too Much of This Common Pain Reliever?

How much is too much?

The maximum dosage of acetaminophen for the average healthy adult is 4,000 milligrams (mg) per day. But that’s a general guideline, Issa says. In older people, the daily max may still be toxic to the liver.

“If you’re taking it over a long period of time ... I would recommend less than that, maybe even 3,000 mg per day, especially if you have coexisting conditions that increase the risk of liver damage because you start accumulating toxic compounds in your body,” Issa says. “The more there are of these toxic compounds, the more injury to the liver.”

When to see a doctor

Symptoms of an acetaminophen overdose include nausea, vomiting, abdominal pain and, as it progresses, a yellowing of the eyes and skin, Le says.

“You may not have specific symptoms right off the bat, but within two to three days, a pain in the upper right side of the abdomen,” between your ribs and your belly button, sets in, and the whites of your eyes turn yellow, all of which suggest liver damage.

But here’s where things get complicated: Some people have no symptoms; with others, it may take several days for symptoms to surface. And even when they become apparent, they can mimic those of the flu or a cold, making them easy to disregard.

“Once you start seeing that yellowish discoloration, it’s more evident that the liver injury is starting to happen,” Issa says. “That why it’s important to watch for early warning signs, so you can seek medical care before it proceeds to complete liver damage.”

Play it safe 

To avoid the risks that come with taking too much acetaminophen:

Read the fine print. Before you buy a particular pain reliever, read the Drug Facts label to see if acetaminophen is listed among the ingredients, especially if you’re using multiple analgesics at the same time. If too many contain acetaminophen, talk to your health care provider about whether it makes sense for you to substitute one or more with an NSAID.

“There are so many compounds out there that have acetaminophen in them, and it's not advertised, and we’re not even aware of them,” Issa says. “With any medicine we take, it’s really important to see if it includes acetaminophen because that should be counted in the total amount of acetaminophen that is considered safe.”

Do the math. Look at the label of all the pain relievers you’re taking and note the overall number of milligrams of acetaminophen. When taking stand-alone acetaminophen, keep in mind: Each capsule or tablet may contain anywhere from 325 to 650 milligrams of the drug. At the higher levels, it can be easy to unwittingly exceed the maximum dosage.

Know whether your medications interact. When your doctor prescribes a new medication, ask whether it contains acetaminophen, since that’s often included in combination with certain drugs (opioids and the antihistamine diphenhydramine, for example). Remind them of everything else you’re taking, both prescription and nonprescription, as well as supplements. For the existing prescriptions in your medicine cabinet, look for a list of ingredients on the container label. If you can’t find it, call your pharmacy. “Some medications can interact with acetaminophen — including anti-seizure meds, blood thinners and supplements like St. John’s wort,” Le notes.

Avoid alcohol. People who take acetaminophen and drink alcohol to excess are asking their livers to work overtime. “One of the most common causes of liver failure worldwide is in people who drink a lot of alcohol and take acetaminophen,” Issa says. Drinking alcohol causes the liver to convert more of the acetaminophen you take into toxic byproducts. If you drink, stick with the Dietary Guidelines for Americans-recommended amount: no more than two drinks per day for men and one per day for women.