Butt out rectal paracetamol!

Another study which confirms my view that for all the good 1 g of rectal paracetamol does you may as well shove it up an arse comes from Holmer Pettetson et al in Acta Anaesthesiologica Scandinavica July 2006. This dose of paracetamol after cardiac surgery resulted in "extremely low" plasma concentrations of paracetamol, and even after 4 doses of 6 hourly rectal 1 g paracetamol plasma concentrations remained low and well below analgesic or antipyretic levels. Of course the surgery and the patients in this study are very different from caesarean section and other types of surgery, but I doubt that the rectal absorption is so different to disregard these results. The comparative dose of intravenous paracetamol again demonstrates that plasma concentrations redistribute quite rapidly, so that by 80 minutes the level is half what it was, and still falling. Again, I suspect that the effect (if there is any) of IV paracetamol on a cesarean patient with a regional block may be wasted. Intravenous paracetamol after caesarean section warrants investigation, and until such information is available it should not be routinely used.