Preferential COX-2 inhibitors -Do they add for post-operative analgesia?

ABSTRACT

The preemptive use of nonsteroidal antiinflammatory drugs [NSAIDs] for postoperative analgesia is controversial because of a questionable benefit against increased risk of haemorrhagic complications. Meloxicam is a new NSAID with a pereferential COX-2 inhibitory activity and a better safety profile. In the present study, the efficacy of meloxicam and ketorolac, a nonselective commonly used NSAID, in relieving postoperative pain when given either before or after the operation and their effect on platelet function were compared. The study was conducted on 80 patients undergoing peripheral orthopedic surgery of 1-2 hours duration. In a randamized double blind fashion, patients received either I.M. meloxicam 15mg/day [Group M], or I.M. ketorolac 30mg 6 hourly [Group K], starting 30 min before the operation [subgroups M[1] and K[1] respectively] or just after closure of surgical wound [subgroups M[2] and K[2] respectively]. Pain scores [10 cm visual analogue scale] [VAS] were obtained for all the patients immediately after recovery and at 1/2, 1, 2, 4, 8 and 24 hours after recovery. Time latency to the first request of additional analgesic and the amount of the first 24 hours consumption of pethedine analgesia were also recorded. In order to evaluate the effect of the drugs on intraoperative hemostasis, bleeding time and platelet aggregation studies were obtained before and one hour after giving the premedication drugs in the subgroups M[1] and K[1] and also in M[2] as a control. There was no significant difference in VAS, in the amount of first day consumed pethedine or in the time latency to the first request for additional analgesic between patients who received either meloxicam or ketorolac, whether they received the drugs before or after the operation. However, patients who received either of the drugs before the operation has significantly less pain scors during the first 8 hours [in meloxicam subgroups] and 4 hours [in ketorolac subgroups], and consumed less pethedine than those who received the drugs after the completion of surgery. Intra-operative bleeding time was significantly prolonged relative to the preoperative values in the three tested subgroups. However, there was no significant difference in the changes that occurred in bleeding time between patients who received meloxicam and placebo. Patients who received ketorolac had significantly more prolonged bleeding time than those who received meloxicam or placebo. Ketorolac also induced significant depression in platelet aggregation while meloxicam and placebo did not. Equal levels of post-operative analgesia can be obtained by either meloxicam or ketorolac. Preoperative administration of either drugs provides better post-operative analgesia during the first few hours after recovery. In contrast with ketorolac, meloxicam does not affect intraoperative platelet function if given before the operation. Meloxicam is equally effective, but can be more safely administered preoperatively than ketorolac