Translation from French: paracetamol is preferred over nonsteroidal anti-inflammatory drugs (NSAID). Dose of paracetamol should not exceed 3g/day and doses should be spaced throughout the day.
Which is itself the leading cause of acute liver failure in the US. The active dose is very close to the lethal dose, much more so than naproxen or ibuprofen.
The active dose is nowhere near the lethal dose. It is however close to the dose where you could see some minor damage to the liver. It causes problems because people are addicted to opioid drugs that are typically combined with acetaminophen, not because they are loading up on acetaminophen itself.
Paracetamol is dangerous in overdose, and the therapeutic dose is pretty close to the overdose amount. The therapeutic index is approx 10.
Compare that to morphine, which has a therapeutic index of about 70.
(although the therapeutic index is tricky to use because of dose response curves)
We know that paracetamol is commonly used in both accidental and deliberate overdose. And this is true in countries that don't have the opioid crisis, and it was true in the US before the opioid crisis.
> It causes problems because people are addicted to opioid drugs that are typically combined with acetaminophen,
- "Liver toxicity from acetaminophen poisoning is by far the most common cause of acute liver failure in the United States, researchers reported" [1] in 2005. It was also true before the opioid epidemic really began.
- "The recommended dose of acetaminophen in adults is 650 to 1,000 mg every 4 to 6 hours, not to exceed 4,000 mg in a 24-hour period." [2]
- "Single doses of more than 150 mg/kg or 7.5 g in adults have been considered potentially toxic." [2]
- "The minimal dose associated with liver injury can range anywhere from 4 to 10 g" [2]
The active dose is very close to the dose at which liver damage occurs (4X single dose or 1X daily dose) and also a fatal dose (10X single dose or 2.5X daily dose). Further, it's exacerbated by alcohol use, which is why you should never drink and then take Tylenol.
Wheres, ibuprofen the safety margin is 120X a single dose and 40X a daily dose. For naproxen, it's 63X a single dose or 21X a daily dose [3].
Ibuprofen is OTOH much riskier and disadvised for many groups of patients, like those with gastric problems (Ulcertativ Colitis, Crohn's etc.)
The problem is often due to people overdosing, often due to mixing different pills that each contain paracetamol. Each cure becomes poison after a threshold.
Right, and I'm saying that threshold is much lower for Tylenol than other NSAIDs, separate of whether it's disadvised for certain demographics. That's fact.
Ibuprofen already is known to lead to GI perforation and mental decline in the elderly, so there's rarely a compelling reason to administer it. Paracetamol is much safer over short durations for analgesic and antipyretic properties generally unless acute or chronic liver injury is suspected.
Maybe there are different recommendations where you live, but here in Sweden and most of the hits on a web search suggest max dosage of paracetamol is 4g/day spread out.
Upper tolerable dosage isn't as simple as one number for everyone. How much someone can take depends on how long someone takes it, their relative health and their mass dosage (mg/kg). I could take 2g c.i. (6g/day) for weeks (114 kg, large healthy liver, younger) but a little grandmother (40 kg) couldn't.
