LOS ANGELES — The Food and Drug Administration has asked doctors, dentists, pharmacists and other health care professionals to stop giving patients high-dose acetaminophen, the active ingredient in the popular pain-reliever Tylenol.

Pills, capsules, tablets, syrups and other formulations that contain more than 325 milligrams of acetaminophen have not been shown to reduce pain better than lower doses of the medication; however, such high levels of the drug can cause liver damage, the FDA explained in a recommendation issued Tuesday.

Pharmacists who are asked to fill prescriptions for medications with more than 325 mg of acetaminophen should contact the doctor or dentist who ordered it and see if a lower dose would suffice, the recommendation said.

The FDA has warned consumers about the risk of inadvertent overdoses of acetaminophen, which can happen when people simultaneously take several drugs that contain the painkiller. Reducing the maximum dose of acetaminophen should also reduce the risk of an accidental overdose, since nearly half of such cases involve a prescription medication, according to the FDA.

Patients who have too much acetaminophen in their systems can suffer liver failure.