Pain Reliever Caution

Tylenol can cause liver damage. The active ingredient in Tylenol is acetaminophen. Unintentional acetaminophen overdoses are now the leading cause of acute liver failure in the United States. Four grams per day (equal to about 12 regular-strength Tylenol tablets) is considered the safe maximum, but that might be a bit much for some. In a study covered last year, more than a third of the subjects assigned to take 4 grams of acetaminophen daily for two weeks (sometimes in combination with other drugs) had unusually high liver enzyme levels. It’s hard to say from this study whether the in­creases were temporary or medically important. Large doses are the main risk, but there are reports of people developing liver troubles after taking small to moderate quantities of aceta­minophen for long time periods.Acetaminophen is an ingredient in many over-the-counter cold and headache medications. As an example, Extra Strength Excedrin contains 250 mg.and prescription pain relievers like Percocet and Vicodin also contain acetaminophen. Some people may be taking more of the drug than they real­ize because of these buried sources. The danger here needs to be kept in perspective. Millions of Americans take acetaminophen each year, yet the cases of overdoses causing acute liver failure number in the hundreds, and a large percentage of those are suicide attempts. Over all, it’s a remarkably safe drug.

Most of the pain relievers that we’re acquainted with, like ibuprofen, naproxen, and some that aren’t so conversant, like diclofenac (Cataflam, Voltaren), are nonsteroidal anti-inflammatory drugs (NSAIDs). As the name implies, they quell pain by quieting inflammation. Acetaminophen is not an NSAID. It is not anti-inflam­matory and relieves pain in other ways.

All the NSAIDs may increase heart attack risk. NSAIDs revo­lutionized the treatment of pain but have the drawback of being hard on the stomach and in extreme cases, cause gastrointestinal bleeding, a seri­ous-sometimes deadly fallout.

The COX-2 inhibitors-celecoxjb (Celebrex), rofecoxib (Vioxx), valde­coxib (Bextra) were supposed to be better NSAIDs: a new generation of medications that would relieve pain just as well as, if not better than, the old NSAIDs, but spare the gut. It hasn’t worked out that way. Vioxx was jerked from the market three years ago after it was linked to an increased risk for heart attacks. Lawsuits and endless court cases and a bitter controversy about incomplete reporting of research re­sults resulted. Bextra went off the mar­ket a few months after Vioxx because of possible cardiovascular effects and a link to a potentially fatal skin disease.

Soon all the NSAIDs fell into a cloud of suspicion-and it’s still there. Finnish researchers reported last year that current use of all NSAJDs-even the traditional ones-increased the user’s risk of having a heart attack. An earlier Danish study came to a similar conclu­sion. When a pair of Australian research­ers combined the results from 23 stud­ies, diclofenac, indomethacin (fndocin), and Vioxx stood out as the NSAIDs most likely to have cardiovascular side effects. Ibuprofen and piroxicam (Feldene) increased risk only slightly, and naproxen caused no problems. Low doses of Celebrex seem to be safe. After the bad news about Vioxx and Bextra, the future of all the COX-2 drugs was in doubt. But Celebrex has remained the market, and at doses of 200 mg per day or less, doesn’t seem to make a heart attack any more likely