An FDA drug advisory panel last week recommended banning Vicodin and Percocet, two extremely commonly prescribed strong pain killers, because of the amount of Tylenol combined in each drug. The committee also implied that the current recommended maximum daily dose for Tylenol — 4000 mg — is too high for safety, but did not offer specific guidance about how to act on that conclusion.
Background
Tylenol overdosage is known to create severe and often fatal liver damage. The currently recommended maximum dosage for Tylenol (the generic name is acetaminophen) is 4000 mg per day, equal to 8 of the 500-mg “extra strength” tablets or about 12 of the standard 325-mg tablets. The standard dosage of Vicodin contains 5 mg of hydrocodone and 500 mg of acetaminophen. Each Percocet contains 5 mg of oxycodone (somewhat stronger than hydrocodone) and 500 mg of acetaminophen.
The committee’s concern appears to be that people in pain may frequently exceed the recommended dosages of those drugs, and thereby ingest well more than 4000 mg acetaminophen per day, and also that acetaminophen is quietly present in many over-the-counter formulations that may be taken at the same time and therefore lead to overdosage on acetaminophen and high risk of liver damage. For example, Tylenol PM, which is an OTC sleeping aid, contains 25 mg of the sedating antihistamine, Benadryl, but also, for reasons known only to the manufacturer, 500 mg of acetaminophen. With the recommended dosage of two caplets, the person receives 1000 mg of acetaminophen, which has no sedating properties. Hence risk to the liver, but no benefit to sleep.
Incidentally, another reason many pain medications are combined with acetaminophen (such as Tylenol #3, which contains 30 mg codeine and 325 mg acetaminophen) is to make it more difficult to abuse the narcotic by simply dissolving the tablet and then taking it intravenously. Such combined drugs are less tightly controlled by the Drug Enforcement Administration and make our pain control supply lines much less cumbersome for pharmacies and doctors.
What We Have Been Doing
We regularly prescribe narcotics for severe pain. They are important drugs. But we have, for several years, preferentially used a formulation of hydrocodone (brand name Norco) that contains no more than 325 mg of Tylenol with 10 mg of hydrocodone, whereas the Vicodin product would have 1000 mg Tylenol for the same amount of hydrocodone. And we frequently use hydromorphone, a narcotic that is strong enough to use without supplemental Tylenol at all, instead of Percocet. And we certainly recommend alternative pain killers, such as ibuprofen (Motrin and Advil), good old aspirin, and naproxen (Aleve and Naprosyn). But for Tylenol, we have been guided, as everyone, by the current recommended maximum of 4000 mg per day. That amount may be too much.
Remember that the advantage of acetaminophen over aspirin or ibuprofen and other similar analgesic drugs is that acetaminophen does not produce stomach irritation or intestinal bleeding, which can be problems with those drugs and a real danger, especially in older patients, but also in people of any age. So there is no totally safe harbor to run to. As is often the case in medicine, we must balance benefits and risks, and try to judge these as accurately as possible for each individual.
Committee Wants Lower Limit
The committee indicated that, in their opinion, 4000 mg of acetaminophen daily was too much. But they did not say nor offer specific guidance nor data as to what lower level would be safe. Should it be 3000 mg daily, or 2000? The lower the recommended limit, the more we will need to use alternatives such as aspirin and ibuprofen and the more we risk the side effects of those drugs. But banning narcotic combinations with high dosages of Tylenol at least will ease the risk of liver damage in the setting of acute pain, when overuse of prescriptions is relatively common.
What We Recommend on Tylenol
We all should be more careful with Tylenol (acetaminophen). In the absence of any firm, evidence-based guidelines from the FDA, we recommend that:
- Our daily maximum for acetaminophen should be 3000 mg daily (9 regular strength tablets) and that target regular usage should probably not exceed 2000 mg (6 regular strength tablets).
- We need to make more use of aspirin and NSAIDs such as ibuprofen (Advil) and naproxen (Aleve) for standard pain control, especially by alternating them with acetaminophen during the same day. This is an effective pain control strategy and should lower the risk to the liver from acetaminophen and also lower the risk of intestinal bleeding from the aspirin and NSAIDs.
- We must be very careful of alcohol consumption when taking Tylenol on a regular basis. The combination appears to be particularly risky. (This warning does not preclude taking 2 Tylenol for a headache after a big dinner.)
We expect further information and professional recommendations will circulate over the summer. Given the enormous economic implications to the McNeil corporation, which has succeeded in occupying a large portion of all pharmacy shelving with various Tylenol product extensions, it will be an exciting story to follow.
