system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why it is unsafe to drink rubbing alcohol?

I know this sounds horrible, and I will never do it, but It is just alcohol isn't it? Why isn't it possible to mix a drink with it?
gpt
Alcohol is just a class of organic molecules that has a hydroxyl group attached to a single carbon (methyl alcohol) or a chain of carbons. When alcohol enters your body it get metabolized to form a ketone or an aldehyde. What metabolite is produced is dependent on what alcohol is being metabolized. Regular drinking alcohol (ethyl alcohol) gets metabolized into acetaldehyde which isn't very toxic to humans but is part of the reason you feel hungover. When rubbing alcohol (isopropyl alcohol) is metabolized it forms a ketone called acetone, also known as nail polish remover. Acetone acts as a central nervous system depressent and will lead to headaches then dizziness then vomiting then a coma if taken in large enough quantities. 

So it's really not the rubbing alcohol that hurts you its what your body does with it. If someone drinks rubbing alcohol or antifreeze which contains methyl alcohol (metabolizes into formaldehyde) of course the best thing to do is get them to the hospital. If that's not an option for some reason, getting them drunk and keeping them drunk for a while will also save them. This is because ethyl alcohol has a higher affinity for the enzyme that metabolizes all alcohols so your body will be too busy metabolizing the ethyl alcohol to metabolize the other alcohol. Eventually the isopropyl or methyl alcohol will be excreted in the urine and no harm will be done.