Placebo controlled comparison of the opioid sparing effect of meloxicam and diclofenac after abdominal hysterectomy

Objective: To compare the opioid sparing effect of meloxicam, diclofenac, and placebo after abdominal hysterectomy. Methods: This study was conducted at the Riyadh Military Hospital, Riyadh, Kingdom of Saudi Arabia from February 2004 to November 2006. Women of American Society of Anesthesiologist's classification I or II of ages 25-60 years scheduled for abdominal hysterectomy were included. Those with significant systemic disease or contraindication to opioid or non-steroidal anti-inflammatory drugs were excluded from the study. All patients received general anaesthesia and intravenous (IV) morphine, and were intubated and ventilated for the operation. The patients were randomized and rectally received meloxicam (15 mg), diclofenac (100 mg), or placebo suppository. Patients, anesthetists, and nurses managing the patients postoperatively were blinded to these drugs. In the recovery room, (IV) patient controlled morphine was commenced. The information sought included patient characteristics (age, weight), duration of operation, and doses of morphine consumed in 24 hours. Results: Seventy-five patients (25 in each group) participated in this study and only 5 patients dropped out. There was no difference in age and body weight of the patients, and duration of the operation. All underwent either total or sub-total hysterectomy. The mean (SD) morphine consumption in the 24-hour postoperative period was 37.7 (11.1) mg for the diclofenac group, 40.1 (7.8) mg for the meloxicam group, and 45.2 (9.8) mg for the placebo group. As compared to placebo, the mean morphine consumption in diclofenac (but not in meloxicam) group was significantly (p<0.05) reduced. Conclusion: Our study demonstrates a significant opioid sparing effect after abdominal hysterectomy with diclofenac, but not with meloxicam.