Comment by sixeyes
10 hours ago
Wiki for phenacetin says it's mechanism of action is being metabolized into paracetamol. IDK about your "nowhere as effective".
It was withdrawn for sometimes being metabolized into another, toxic and carcenogenic, molecule.
Here is a summary of COCHRANE evidence on Paracetamol "widely used and ineffective"[0].
It's a paradox no?
Paracetamol is only the presumed only active metabolite, and that is why paracetamol rapidly replaced phenacetin.
There is a quirk though, phenacetin actually delivers paracetamol to your brain and spine (where it primarily reduces pain) faster than an oral dose of paracetamol.
Similarly IV paracetamol is far more effective that oral paracetamol.
Phenacetin was also considered mildly addictive, and induced a gentle euphoria and then sedation.(We still see sedation after paracetamol in children and the elderly). But general use we don't see these effects in paracetamol, why did phenacetin do this more effectively? Probably the higher peak levels around nerve endings.
These effects are both wanting of an explanation of phenacetin is just paracetamol and directly analegisic.
[0] https://web.archive.org/web/20240721144157/http://www.eviden...