Bum Knee? Sore Back? Achy Wrist? Read This

Hearing more and more grouching about bad knees and cranky backs from friends and family? So are we. And it's not just old hippies who partied hard at Woodstock or silver-haired tennis players doing the complaining. More than half of those with arthritis are under 65. And who knows how many video-game addicts are walking around with inflamed wrists and carpal-tunnel problems who are going to need surgery soon -- heck, Mehmet and I think they're all preop, and we already have enough business.

With ouchy joints on the rise, pain reliever sales will go up, too. And that can lead to a whole different kind of health problem: accidental overdoses of acetaminophen (Tylenol), which can quickly do in your liver. Liver transplant centers are reporting steady increases in acute liver failure -- nearly half of them due to acetaminophen overdoses.

Considering how many people take this ordinary pain reliever every day, it's amazing how rare overdoses are. That said, they're the single most common cause of acute liver failure in the country. And the effects can be fatal: A third of people -- wow, a third -- who develop liver failure die without a liver transplant, which is risky in itself. It's big-time surgery with difficult anesthesia challenges. And by the way, those one-in-three statistics don't include liver patients who die before they get to a transplant center or people who just feel really, really sick but don't know why.

We're not trying to scare you off acetaminophen. No way. It's an excellent pain reliever, which is why it's the most widely used analgesic in the U.S. But like any drug, prescription or not, you need to use it with care. Here's how:

• Know your limits. The maximum recommended dose is 4 grams a day. More than that can be toxic. Check the label, and keep tabs on how much you take. Don't assume all formulas are the same. For instance, each "Arthritis Pain Relief" caplet contains 625 milligrams (mg) of acetaminophen -- not the standard 500 mg in a basic pill.


• Don't take it daily for long. The label says, "If pain lasts more than 10 days, consult your physician" -- and means it. In one study, half the healthy volunteers who took 4 grams a day for 2 weeks (just 4 extra days) had abnormal liver tests. That may partly explain why last year the American Association for the Study of Liver Diseases (AASLD) urged the FDA to warn people that the risk of severe or fatal liver injury is high if they take 4 grams a day for just 5 days in a row.


• Comparison shop. Acetaminophen is used in hundreds of over-the-counter products, including many cold and sinus treatments. It's in prescription drugs, too: Vicodin contains 500–750 mg; Avocet has 325–650 mg. Don't mix any meds until you've checked ingredient labels (and package inserts). It's way too easy to slide over the max without knowing it. Alternatively, if you're male and over 35 or female and over 40, you can try taking two baby aspirin a day and see if it's enough to help your joints -- because taking that much daily is enough to help your heart and arteries. But you must talk to your own doc before trying this.


• Don't drink when you're taking it. All acetaminophen labels say, "If you consume three or more alcoholic drinks every day, ask your doctor whether you should take acetaminophen." The AASLD wants the FDA to specifically warn people not to take more than 2 grams of acetaminophen a day while drinking alcohol. We say, don't even think about mixing the two.


• Don't just read that tiny print, believe it!