SubEx

Myth check

Tylenol and your liver: almost half the failures were accidents

Of acetaminophen liver failures at 22 US units, 48% were accidents. Asked to show a day's use, 46% of patients handed two products containing it went past the daily limit.

Acetaminophen (Paracetamol)

Paracetamol, the drug in Tylenol, has a reputation as the mild painkiller. Of the liver failures it caused at 22 US specialist units, 48% were accidents, and 38% of those people had been on two or more products containing it. Handed real boxes, under a quarter of patients showed a day's use past the limit with one product and 46% with two, though showing is not doing. The failures that reach these units are as often accidents as attempts.

The findings behind this

1
Physical & bodyAlmost half of acetaminophen liver failures were accidental

Acetaminophen caused 275 of 662 acute liver failures at 22 US centres, and 48% of those were accidents. Of the accidental group, 38% had taken two or more products containing it.

★★★Well replicated — this finding’s sources average out to meta-analyses, systematic reviews or high-powered trials.Tertiary referral centres see the worst cases, so 42% is acetaminophen's share of the liver failures that reach those units and never a risk to anyone taking it. Doses in the accidental group were reconstructed from what patients recalled afterwards. The three routes overlap, so one person can sit in all of them and the percentages do not add to a hundred. The narcotic-combination finding is US-specific, since those products are not sold everywhere.Click to keep this openRelieve painAcetaminophen (Paracetamol)
2
OtherWith two acetaminophen boxes to hand, 46% dosed past the daily limit

Five hundred primary care patients showed how they would take real boxes over a day. Just under a quarter went past 4,000 mg using one product; with two, 46% did.

★☆☆Contested — the evidence disagrees with itself, or the finding carries a caution. A caution or conflict always shows one star, however strong the sources are.CautionPeople were showing what they would do, not observed doing it at home, so this measures intent and understanding rather than behaviour. A public hospital clinic and a community practice were among the four sites, and the sample leans towards lower health literacy, which was itself one of two independent predictors of going over. The threshold scored against is the 4,000 mg liver warning rather than the lower per-product ceiling many labels now print, so against that figure the rates would be higher still.Click to keep this openRelieve painAcetaminophen (Paracetamol)

More on this

All stories →