The results could be undertreatment of pain, or putting patients on even stronger narcotics. Better labeling of medicines that have acetaminophen is the answer, rather than making them less available, said Fanciullo, a pain management specialist at Dartmouth-Hitchcock Medical Center in Lebanon, N.H.

Dave Duhrkoop, a retired marketing manager in Troutdale, Ore., has taken Vicodin and Percocet for severe back pain. He's now on a different drug but thinks banning the other two would be overkill. It could lead chronic pain sufferers to turn to street drugs "because people don't want to hurt."

According to the FDA, prescription acetaminophen combination drugs were prescribed 200 million times last year. Tylenol's maker says nearly 50 million U.S. adults and children take acetaminophen in any given week.

The panel's proposals, announced June 30, were prompted by concerns over acetaminophen overdoses, which are the leading cause of liver failure. They sicken more than 50,000 people and cause at least 200 deaths each year nationwide.

Poisoning is not believed to be a risk for long-term users of recommended Tylenol doses, and they do not need liver tests, said Dr. William M. Lee, a liver disease specialist at the University of Texas Southwestern Medical Center in Dallas.

Liver problems associated with excessive use of Tylenol and other forms of the drug tend to occur suddenly. They typically show up within about three days of taking extra doses, Lee said, and even a few extra pills over a few days can cause problems.

That's why the FDA panel recommended making the current maximum single dose of Tylenol, 1,000 milligrams, available by prescription only. The new maximum single dose would be 650 mgs. The total daily limit would be cut from 4 grams, about 12 regular-strength Tylenol pills, to an unspecified lower dose.

Symptoms of liver problems include nausea, vomiting, upper abdominal pain and jaundice. With immediate treatment, permanent liver damage can be prevented.

The recommendations led Tylenol's manufacturer to run full-page ads in major newspapers Friday declaring the medicine is safe when used as directed. The ads also say never take more than recommend doses, and don't use two products containing acetaminophen at the same time. That includes over-the-counter cold medicines such as Nyquil and Theraflu, and prescription medicines also containing the drug.

The Arthritis Foundation issued a statement supporting the limits, saying that arthritis patients "must be made aware of potential side effects of drugs so they can decide about the level of risk they are willing to accept."

Lee, the Dallas liver specialist, also supports the proposed limits. He provided data on acetaminophen poisoning to the FDA advisory panel.

The full FDA is considering the recommendations, but any final decisions are months away.

The proposed ban on Vicodin and Percocet is justified because they're so easy to abuse, Lee said. The narcotics in these drugs are addictive and can lead users to take increasingly higher doses — but that also means increasingly higher amounts of acetaminophen.

Quoting a colleague, Lee said it makes no sense to combine a highly addictive drug with a "dose-related poison. It's like putting poison and candy together."

Oxycodone, the narcotic in Percocet, can be prescribed separately. But Vicodin's narcotic ingredient is hydrocodone, which isn't available alone.

The risks for liver failure justify the restrictions, Lee said.