Liver function tests

Amiodarone, amiodarone, amiodarone.

I know many times people think of amiodarone in terms of the PFT, LFT, and TFT issues, and I'm gonna talk about those.

But one thing that's also really important to know about amiodarone is that it deposits in the skin, and it actually makes your skin more susceptible to ultraviolet radiation, right? So it can actually cause like sunburns.

People can become photosensitive.

But, right, remember amiodarone, um, it's a ver-- it's a drug that binds lipids very well.

Uh, so basically, wherever you have a lot of lipid-rich tissue, it can cause a lot of problems, right? So, um, it can deposit in the liver, right? The liver contains quite a bit of fat, right? And it can cause, uh, liver toxicity.

Um, so it can raise your LFTs.

Um, another thing amiodarone can also do, right, is it can cause pulmonary fibrosis, right? Again, it can deposit in the lungs.

Yeah.

So actual liver function, you know, we think about LFTs or AST and LLTs, but really bilirubin and INR are the most useful.

AST and ALT are really markers of hepatocellular injury, not function.

And they can be dramatically elevated in somebody with acute injury and relatively unimpressive with somebody with advanced cirrhosis.

It's just been the best studied in those, uh, populations.

And then since we're kind of talking about [clears throat] this, uh, list of things that are, um, you know, that kind of work on the blood system and the coagulation cascade and whatnot, right? Uh, again, if they, if they give you a question about a child, right, and they tell you that this child, you know, um, has been having a lot of ringing in the ears and that, you know, he's been having a elevation in his LFTs, has like profound hypoglycemia, that his parents gave him [clears throat] a tablet, uh, for, you know, for, you know, the, the child was having headaches and joint pain.

If you see something like this, right, you wanna think about aspirin, right? So remember aspirin, the big things to know about aspirin.

Remember, compared with NSAIDs, aspirin is an irreversible COX-1 and COX-2 inhibitor, right? It's an irreversible COX-1 and COX-2 inhibitor.

So let's continue.

Let's go ahead and continue here.

Um, and then, uh, let's maybe look at acetaminophen, right? So remember acetaminophen, um, the, you know, the classic way they can test this is a person trying to commit suicide, right? And you notice that, ooh, this person's LFTs are markedly elevated.

And then they ask you, right? Be-because see, guys, the USMLEs are not stupid, right? They know that many of you have memorized, oh, one of the ways acetaminophen causes toxicity is because of NAPQI.