O.D.ing on painkillers.

[Daecon]

Just out of morbid curiosity...

 

I think there are 3 common types of painkiller: paracetamol, aspirin and ibuprofen?

 

What physiologically happens to the body when it's exposed to a (lethal) overdose of these painkillers, and what kinds of differences are there between the three when this happens?

[ecoli]

lots of vomiting for all three, I'm sure.

[aj47]

Hepatotoxicity where the liver fails is the main problem, but i'm sure there are other things as well.

[prion]

The only one I really know about is paracetamol (aka acetaminophen). Paracetamol itself isn't toxic even in an overdose. The damage is done by a metabolite of paracetamol. When you take a normal dose of the drug, the liver processes it into harmless metabolites that pass out in the urine. When someone takes an overdose, those normal processes get overwhelmed and the drug undergoes other chemical reactions in the liver, that make a very toxic metabolite called NAPQI. This can still be safely and quickly inactivated by the liver by joining it to glutathione. But if you take enough paracetamol, the liver will eventually run out of glutathione so that the NAPQI builds up and damages the liver cells. The worst thing is that in a healthy person it can take a couple of days to get to that point, and the person could walk round feeling only a bit ill, then suddenly go into liver failure. It's so sad when people come into hospital because of it, they probably thought it hadn't done anything to them and all the time their liver's been slowly wrecked. It's really nasty stuff in overdose, that's why there are such strict rules about how much you can buy at one time in the UK.

 

I think the other ones you mentioned have more of a direct effect, i.e. too much of the drug causes problems by itself. I know aspirin upsets the body's pH.

[Daecon]

Does a similar reaction happen with sleeping tablets, or is that a different chemical response?

[prion]

not sure about sleeping tablets. I think with most drugs it's an exaggeration of what they do normally, and then some other toxic effects that only happen when there's too much of it. For example alcohol is a depressant, so a bit will impair your mental function, a lot will affect your physical function, and a huge amount will totally stop you breathing. Presumably other depressants would do the same

[wpenrose]

What physiologically happens to the body when it's exposed to a (lethal) overdose of these painkillers' date=' and what kinds of differences are there between the three when this happens?[/quote']

 

Aspirin causes acidosis. It lowers the blood pH. Only a fraction of a pH unit will bring you to grief. The only treatment is hemodialysis.

 

Acetaminophen (tylenol) trashes the liver, especially when taken with alcohol.

 

I don't know what ibuprofen does.

 

Dangerous Bill

[jdurg]

Ibuprofen is one of the safest of the OTC pain relievers. It doesn't get metabolized into a horrifically nasty substance, and it's interaction with alcohol is minimal at best. Ibuprofen is classified as a Non-Steroidal-Anti-Inflammatory drug. (An NSAID). NSAID's typically will thin the blood and reduce the levels of prostaglandins present in the blood. (Prostaglandins play a large role in maintaining blood pressure).

 

High doses of Ibuprofen may result in reduced kidney function as Ibuprofen reduces the flow of blood into the kidneys. As a result, normal blood metabolites which are typically excreted may not be filtered out of the blood. Lithium ions typically build up the fastest and an OD on Ibuprofen can lead to lithium toxicity due to its lack of removal from the blood. The biggest consequence, however, of an Ibuprofen overdose is internal bleeding. Ibuprofen, like most NSAIDs, thins the blood considerably and an OD can result in internal bleeding that can be difficult to stop.

 

Acetylsalicylic Acid is also an NSAID and has similar issues in addition to the pH lowering problem. Aspirin is also not a good combination with alcohol. Whenever I've been drinking a bit too much I'll reach for the Advil and completely avoid the Acetaminophen and Aspirin. (Acetaminophen and alcohol is just asking for death).