Many years ago after a surgical procedure I was given a prescription for Vicodin, which is the brand name combination of hydrocodone and acetaminophen. Hydrocodone is an opiate analgesic and acetaminophen is the generic name for tylenol. There was not (as still is not) a version of hydrocodone all by itself - you can only get the two in combination.
Now, the hepatotoxicity of acetaminophen was and is well known and currently some 38% of cases of acute liver failure are due to acetaminophen ingestion. You can get liver failure taking 15 extra strength tylenol a day or as little as 4 if you have liver damage from alcohol. I remember being annoyed that in order to get narcotic pain relief I was being forced to take a hepatotoxin that added little to the pain relieving efficacy of the opiate. I speculated to my wife that there were probably more injury and deaths occurring due to the acetaminophen than the "dangerous narcotic" in the Vicodin.
Now it looks like the FDA is starting to recognize the same thing that was obvious to a radiologist 10 years ago. It seems that as recreational drug users and addicts seek Vicodin for it's narcotic benefits, they are increasingly suffering inadvertent liver toxicity from the acetaminophen, contributing to the 40,000 ER visits per year related to acute liver injury.
Here is story with a good summary.
There is a better review in the WSJ today but I can't link to it.
Tara Parker Pope of the NYT reassures us that acetaminophen is just fine. If you take her dietary advice, though, you probably already have metabolic syndrome. I am personally not so reassured that acetaminophen is safe as long as I don't take too much at once.
What has all this to do with the war on drugs? Well, in the early days of the misguided and counterproductive war on drugs, Richard Nixon signed the Drug Control Act that established "schedules" that doctors and patients must deal with today. The schedules range from IV to I, in order of their "abuse potential". Now, just so you don't get confused and think this had something to do with safety, chemotherapy agents, warfarin and other very dangerous drugs are not on the schedule, but pretty much any drug someone might take at a party is. It was decided that drugs should be made more difficult to obtain based on their potential for "abuse". In keeping with the moralistic and authoritarian origins of all this, "abuse" means "getting high" and has little to do with how dangerous the given drug was to your health. Some drugs, like cannabis, are schedule I and legally unavailable by anyone in most states. Does anyone think cannabis is deadlier than Jim Beam?
That is how you end up with unnecessary acetaminophen in your narcotic. The government figures it has a lower potential for abuse because you will be dissuaded from taking enough of it to "get high' by the potential for hepatotoxicity due to the added acetaminophen! The manufacturer responds to the incentives of the Drug Control act by adding the acetaminophen to get a schedule III classification. This makes it less onerous for the prescribing physician, and easier for the patient, resulting in greater sales for the drug company.
Make the potential party drug more toxic so it is less likely to be "abused".
In case you think my reasoning on this is overly cynical, have you ever purchased denatured alcohol at the hardware store? This is ethanol - the same kind found in your gin and tonic - which has been purposefully engineered to kill you if you drink it. "Denatured" implies there has been some chemical alteration of the alcohol, but in fact it is just intentionally contaminated with toxic solvents like methanol or acetone. The manufacturer goes to extra effort and expense to add poison with the sole purpose of escaping burdensome government regulation and taxation.
So I am glad the FDA is finally realizing what is going on, but it's too bad they don't address the true source of the problem, which is the war on drugs (the "schedule") and the perverse incentives such control attempts always create.
Your government is here to protect you from too much fun, even if it kills you.
PS Hydrocodone has its own toxicity issues, as Rush Limbaugh will attest.
I advise requesting pure oxycodone or maybe percodan postoperatively until they take the acetaminophen out of the Vicodin. I also don't advise taking any drugs for recreation.