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Wednesday, May 11, 2016

Prince's Percocet

At this time it's difficult to tell what role Percocet played in the death of Prince, but there's an aspect of Percocet that is worth considering even if it wasn't a factor for Prince.

Percocet is a combination of oxycodone and acetaminophen. We hear a lot about the addictive dangers of oxycodone, an opioid. We don't hear so much about the dangers of acetaminophen, the over-the-counter drug used in Tylenol. The truth is, acetaminophen can be dangerous — or, as the FDA puts it, "Acetaminophen has a narrow safety margin".

Percocet tablets come in different strengths of oxycodone, from 2.5 to 10 mg per tablet. The prescribing physician selects the dosage of oxycodone based on how severe the pain is, how much risk of addiction there is, how large the patient is and what the patient's experience with opiods has been, and so forth. But every Percocet tablet, regardless of much oxycodone it has, also contains 325 mg of acetaminophen. The same is true of Vicodin, which uses hydrocodone instead of oxycodone.

Why does this matter? Because an overdose of acetaminophen can kill you by wrecking your liver. Acetaminophen overdose has replaced viral hepatitis as the #1 cause of acute liver failure in the U.S. About 50,000 Americans go to an emergency room each year because of acetaminophen overdose, and about 1% of them die. Even when they survive, it's a very unpleasant and expensive recovery that is only partial in many cases. It's an ugly way to go, and it's an ugly condition if it becomes chronic.

The FDA knows all about this problem, but it also recognizes the usefulness of acetaminophen when used in accordance with guidelines. The limit for acetaminophen consumption is 4000 mg a day for a healthy adult. (For someone whose liver is already compromised, it's lower.) Because of the prevalance of acetaminophen overdose, some have argued that the limit should be reduced to 3000 mg a day. Either way, if you stay within the guidelines for acetaminophen dosage, you will not exceed the limit:

  • Two tablets of 325 mg each, four times a day, is 2600 mg per day.
  • If you take two of the larger 500 mg tablets, three times a day, that's 3000 mg per day.
But people who exceed 4000 mg are putting themselves at grave risk. For that matter, even 2600 or 3000 mg per day every day over a long time could be troublesome. If you use that much acetaminophen, discuss it with your doctor who may recommend blood tests of liver enzymes.

Back to Prince. People who get Percocet tablets with low doses of oxycodone — the 2.5 or 5 mg doses that, some say, are easier to get a physician to prescribe — may be tempted to double up or triple up on their consumption of Percocet in order to get the amount of oxycodone that they crave. Problem is, in the process they unwittingly exceed the daily limit on acetaminophen. Did this happen to Prince? I don't know. But it has happened to other people.

By the way, acetaminophen is not the only over-the-counter pain relief medication with a narrow safety margin. Aspirin, ibuprofen (the active ingredient in Advil, Motrin, etc), and naproxen (the active ingredient in Aleve, Accord, etc) are in the same category. And combining the maximum daily dose of several of these NSAIDs can also be dangerous.