Acetaminophen and the liver

Probably the most widely used medication around is Tylenol (acetaminophen) a.k.a. APAP or paracetamol. It's been around for about 150 years and is on the WHO's list of essential medications needed in a health system. That's a good endorsement.

How does it work? Funny story is that nobody really knows. "The analgesic effects are believed to be due to activation of descending serotonergic inhibitory pathways in the central nervous system" - that's the best answer out there.

It's pretty safe for most anybody without an allergy to it (as with every medication) for any manner of things but pain and fever are the actual FDA indications it has. The one big issue with it is liver toxicity. If taken as recommended on the bottle, it is usually harmless, but still, Tylenol overdoses are the number one cause of liver failure in the West. And unlike some other organs, once your liver fails, you need a new one immediately - there is no temporary liver replacement machine.

Imagine your liver is like a baseball stadium. Y'all seem to like the Giants so let's call it AT&T Park. Normal acetaminophen use would be like a scheduled game and security is there to make sure everyone goes in in an orderly fashion without your outside drinks. An expected crowd shows up and the security is adequately staffed to handle them. But if suddenly they decide to make it the last game of the season and it's free BMW day, the regular security staff is going to be overdosed with people and unable to control them from tearing the place apart. That's pretty much the case. The liver can only handle so much acetaminophen at once and anything extra just starts damaging it to the point where it can start dying.

Over the last few years, you may have noticed "extra strength" tylenol (acetaminophen) has gone off the shelves and/or the doses have been reduced. We used to say that 4 grams a day was safe, but now that's been reduced down to 2 grams a day.

Intentional overdoses are one thing that can be a problem, and warning labels won't help with that, but the concern was the accidental overdoses from people who were taking acetaminophen too frequently or then not realizing it was also in some over-the-counter cold remedies or other medications where it's not obvious. There probably also wasn't much added benefit from the higher doses.

So now we say to check the boxes on any over-the-counter medications you're taking and make sure the dose doesn't add up to more than 2000 milligrams per day. A little over is probably OK but keeping to that will be safe even for people with liver problems.

NSAIDs

Advil and Motrin are ibuprofen, then you have Aleve (naproxen). Those are the over-the-counter ones. Prescriptions are Mobic (meloxicam), nabumetone, indomethacin, Toradol (ketorolac), diclofenac, Lodine, and the list goes on. All of these medications are in a class called non-steroidal anti-inflammatory drugs (NSAIDs). I'm giving you this list because there is mounting evidence that these medications a) don't work as well as we'd thought and b) have some very serious long term side effects we're finding out more about. NSAID's act by reducing the amount of prostaglandins you make in order to reduce inflammation. However, prostaglandins have a ton of other effects and are involved in the maintenance of just about AIDs and also stronger if they are taken every day and/or around-the-clock. every other organ system that you have. The effect is stronger with higher doses of NS NSAID's work best and are best indicated for times when something is r...

Kidney Stones

I've written about this previously , but it's often hard to explain to people what a 10 is on the "1-10" pain scale if they haven't been in that spot before. For women who have had children, they generally know what a 10 is, but for men it's a little harder. When I was a medical student on my psychiatry rotation, we had a patient calmly sitting there saying his pain level was at a 10 and our resident, who was an ex-military sniper with a large skull tattoo on his forearm and a crosshair through the eye, calmly leaned forward and asked, "so if I lit you on fire and ran you over with my truck, you could not be in more pain than you are now, correct?" The patient changed his answer. Getting to the point, a kidney stone is about the close I can come to describing a 10/10 pain to people who haven't gone through childbirth. The fundamental issue is similar - your body is trying to move a big solid thing through an opening that was not really desig...

Pain

Sorry to be a pain I would say about 90% of the comments I hear from people about their pain threshold is that they think they have a high pain tolerance. Which is statistically impossible unless I just attract people who have a high pain tolerance. We traditionally ask people to rate their pain on a 1-10/10 scale and while we hear a lot of 9's and 10's, I would say that, having been present for a number of them, a 10/10 would be giving birth to a first child. For those who haven't experienced that, my old psychiatry resident described it as "so if I lit you on fire and ran you over with my truck, you would not be in any more pain than you are now" (he was also a former Marine sniper which might explain that). But this is pretty pervasive throughout the medical system and got me wondering as to how people's understanding of what their pain threshold was matched up to what it really was. Fortunately, there were researchers who had a yen to poke peopl...

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