Does midazolam sedation in oral surgery affect the potency or duration of diflunisal analgesia?

A randomized cross-over study was carried out to determine whether midazolam in doses used for conscious sedation had any effect on the potency or duration of diflunisal, a non-narcotic analgesic used for postoperative pain in oral surgery. Thirty-two Hong Kong Chinese patients of either sex, aged between 16 and 28 years, were given either midazolam to supplement local anaesthesia or local anaesthesia alone at one visit and the alternative at the other visit, for surgical removal of bilateral symmetrically impacted third molars. Surgery was carried out on one side only at each visit. Diflunisal was given for postoperative pain relief. Midazolam had no effect on the potency or duration of action of diflunisal. Independent of the method, more patients had better pain relief following the second procedure than following the first, probably due to a degree of adaptation to the pain, at the second visit.