Vale to valdecoxib

Carvalho et al in September 06’ Anesthesia & Analgesia loked at valdecoxib for postcesarean anlagesia. This drug added little to an already opioid based regimen of 100ug IT morphine with oral oxycodone or hydromorphone and paracetamol. The study was pulled when valdecoxib was withdrawn from the market. The authors concluded that the lack of efficacy was probably due to COX-1 being a mediator of postoperative uterine cramping pain rather than COX-2 which is what valdecoxib inhibits. Nonetheless the failure of this valdecoxib analgesia did not upset the patients: a high proportion of both the experimental and placebo group were satisfied with their analgesia.

Looking at the cesarean studies of diclofenac (the most popular NSAID for cesareans) I find an Wilder Smith’s study in Anesthesia&Analgesia in Aug 03. This was fairly hard-nosed: no intrathecal opioids and IV morphine for rescue only. There were four groups comparing combinations of tramadol, diclofenac and placebo (including an unlucky placebo-placebo group!). The time to first need for rescue was was plotted for individuals on a dot-plot; this demonstrated that the differences of the means in the diclofenac groups was pulled out by a minority in whom diclofenac appeared to have an impressive effect. But for many, diclofenac seemed to do little. Most studies do not present data for individual subjects, and instead compare mean differences. Perhaps we should reappraise these analgesic studies and look at the ranges and (if possible) individual measurements to see just how many do get benefit from these drugs. I have already surmised that these drugs may be doing a bit of harm. A bit of homework.