"The best advice is very simple. Read the label. Acetaminophen is safe if you know how much you're taking. And be sure when combining medications not to exceed four thousand milligrams each day."
As with any medication, you have to follow the directions, be safe, and smart.
"White grapefruit juice increased concentrations of acetaminophen in mice both 1 hour and 2 hours after feeding compared to controls. In contrast, pink grapefruit juice increased acetaminophen concentrations 2 hours after feeding compared to controls."[1]
'P450 Drug Interactions'
Edit - Add;
List of Cytochrome P450 Modulators : https://en.wikipedia.org/wiki/List_of_cytochrome_P450_modula...
'Acetaminophen and Alcohol Hepatotoxicity, Liver damage'
N-acetyl-para-aminophenol (APAP), Acetaminophen, Tylenol, Paracetamol, Panadol, others : https://en.wikipedia.org/wiki/Acetaminophen
They even sell extended release acetaminophen, which prolongs liver processing. Though, I'm not a fan because I think it is rougher on the liver. But health damaging risk is another issue.
That's all very well if people adhere to the instructions but many don't. It's pretty clear why this is so. First, it's an OTC drug and most people associate that with not being as efficacious as drugs that are prescribed by a doctor. Second, people believe OTC drugs to be safe because they are OTC drugs. Third, with the other two factors in mind, given that acetaminophen (paracetamol) is barely an effective painkiller, they opt to up the dose in the hope of obtaining relief.
When I take the drug I'm careful not to take more than 4000mg because of its dangers, in fact I don't ever recall ever taking the maximum daily amount.
I also know the reasons why acetaminophen is dangerous and that further raises my caution. A metabolite of acetaminophen, NAPQI, is toxic to liver cells, it also reduces production of glutathione the agent the liver uses to mop up toxic metabolites. Thus, all's well until the glutathione runs out, after that NAPQI is free to do its damage.
The FDA, doctors and the medical profession need to explain in very simple terms by way of major campaign the reasons for why the drug becomes very dangerous after a certain threshold.
I'm sure an advertising agency could produce a pithy explanation the public would understand (and it should be printed on the box). Irrespective, we urgently need to do something to reduce the thousands of annual acetaminophen poisonings.