Friday, October 26, 2007

Poison

Since the last three were poisons, I wanted to finish this week with a last poison case. Originally, I was going to do radiation poisoning, but the symptoms are too nonspecific. So onto this case, which is an important one to know since it's common...

A college student brings his roommate into the ER. The roommate is confused and disoriented. This is what he looks like:


The patient is sweaty and pale. The roommate says he's been vomiting and lethargic all day. You get some labs and they indicate AST 5000 IU/L and ALT 6000 IU/L. PT is elevated. The roommate says the patient was well a couple days ago.

Challenge: What is the pharmacologic treatment?

Related Questions:
1. What does the image show?
2. What's the diagnosis? What is the biochemical pathophysiology?

Image is in the public domain.

2 comments:

Alex said...

oh, so scleral icterus

is this aflatoxin?? liver cirrhosis causes jaundice / scleral icterus from bilirubin accumulation

Craig said...

Poison

This is acetaminophen overdose. The image shows jaundice. The antidote is N-acetylcysteine (NAC). Acetaminophen accounts for more overdose in the US than any other drug. At therapeutic levels, 90% of acetaminophen is metabolized in the liver, but a small fraction is metabolized by cytochrome P450 into a toxic highly-reactive electrophilic intermediate N-acetyl-p-benzoquinoneimine (NAPQI). If this is conjugated with glutathione, it is converted to a nontoxic compound excreted in the urine. At toxic doses, more NAPQI is made, and it cannot be conjugated. This leads to hepatotoxicity through oxidative injury with centrilobular necrosis. Acetaminophen-induced hepatitis is acute and rapidly-progressing with marked elevation of AST/ALT (>3000 IU/L) and a rising PT. N-acetylcysteine is most effective if started early, and it reacts with NAPQI by supplying glutathione sulfhydryl groups.

Source: UpToDate, Wikipedia.