See: Die Hard With a Vengence. 
Just exactly how toxic is this combo? I mean, before it was well known as Not A Good Thing To Do, I’m sure I’ve done it several times, and maybe even a few times since, and so far, all seems hunky-dory.
That said, I’m sure it’s a toxic combo as warned, but it must take several often repeated occasions before your liver falls off and you die?
The trouble with paracetamol is that the therapeutic dose is close to the harmful dose. The current recommendations are to take no more than 4 g per day, while toxicity might commonly start around 10 g per day (depending on body weight and other factors). So if you’re taking near (or more than) the maximum daily recommended dose, you’re already skating on sort of thin ice, and anything that hurts your ability to safely metabolize it can make things a lot worse quickly.
Basically, when you drink moderately for several days, your liver ups the production of an enzyme that helps break down alcohol,but also breaks down paracetamol into a toxic byproduct (NAPQI). Usually only around 10% of paracetamol is converted to NAPQI, but if you’ve been drinking moderately for several days, that fraction will increase.
So, say you have a drink with dinner, then get a headache. You’re probably fine popping a couple Tylenol pills, because these are probably the first ones you’ve had today, and you probably won’t be having a ton more before bed. The problem is not really the immediate proximity of alcohol and paracetamol, it’s the combination of a large amount of paracetamol after a several day period of drinking.
In fact, say you’ve been drinking 4 drinks a day for the last week, you get a headache, decide to take some Tylenol. If you keep drinking like you have, you’re probably still OK, because the alcohol competes with paracetamol for the liver enzyme (though I wouldn’t recommend trying it). The trouble comes when someone who usually drinks moderately comes down with the flu, feels awful, so both stops drinking and starts taking the maximum dose (or more) or Tylenol every day for a couple days.
http://www.protectpatientsblog.com/2009/07/acetaminophen_tylenol_what_is.html
Wow, that was a great explanation, buddy431. I never really understood the specifics until now – just knew the combination was a bad, bad thing to do.
I have a step mother who enjoys wine regularly and just had brain surgery to remove an aneurysm. She was sort of playing with the pain pill/alcohol combination because she misses drinking her wine. I just sent her your link. Thank you!
Isn’t that the opposite? Chlorine is poisonous and ammonia certainly but I assume ammonium chloride would relatively benign.
Agreed, that was a great breakdown buddy431!
Makes me feel better since I’m not a moderate drinker (only every so often), nor do push taking acetaminophen past the recommended dose.
You don’t get ammonium chloride, you get chloramine vapors, which are highly toxic.
Back in the 50’s there were a number of high profile deaths when people took tranquilizers and later had a drink.
**Buddy431’s **explanation is excellent. I was not previously aware that stopping the drink could contribute to toxicity. Let that be a lesson to us all.
I’d add that some people have a lower toxic threshold than others, just because (presumably genetic factors). Others may be more vulnerable due to baseline subclinical (that is, unknown) liver damage.
Lastly, acetominophen is included in a vast array of over the counter medications. So, to extend **Buddy’s **story: After a 4-day bender, you feel a bit hungover, so you take a few pills. The headache’s pretty bad, so you take a few extra pills and lay off the sauce. Then you decide that it’s a cold after all, so you take a multi-symptom OTC remedy. You can get up to a pretty high dose quicker than you’d think.
Here is a link to a great ‘This American Life’ episode about acetominophen toxicity. There was not much focus on the combination with alcohol (so therefore not so much on the OP topic).
Lead plus high speed can be hard on a body.
We’ve all heard of “high speed lead poisoning” 
So Hannibal was off his meds…
Iron oxide and aluminum make thermite.
They won’t self-ignite in your stomach though.
Glycerol and potassium permanganate might. (Glycerol is non-toxic; LD-50 for potassium permanganate is around 1g/kg body mass, so a spoonful likely wouldn’t kill you on its own.) Together, they could start a nasty chemical fire in your belly, and probably also produce some toxic fumes of acrolein.
Grapefruit juice inhibits the effectiveness of some drugs. So I suppose if you took a live-saving drug but drank lots of grapefruit juice, you could run into trouble. But I don’t know of any particular drug-juice combo that would be particularly dangerous.
It’s well known that the combination of Viagra and nitrates causes extreme low blood pressure or death.
Less well known is that nitrates and star gooseberry tea should not be mixed. I learned this myself. Feeling ill one evening I popped a nitro under-the-tongue, while my wife gave me a home remedy for headache. I stood up … Wham! Blam! I lay down wondering if that was the end. My wife asked if I wanted more tea and I said Yeah. … But rethought, realized the symptom was the same as Viaga+Nitro, asked for water instead. Googling I found cryptic references to star gooseberry and heart disease contraindication. Close call.