Flurbiprofen axetil enhances analgesic effect of fentanyl associated with increase in β-endorphin levels.

Purpose: To examine the analgesic effect of preoperative administration of flurbiprofen axetil and that of postoperative administration of a combination of flurbiprofen axetil and fentanyl, as well as perioperative plasma β-endorphin (β-EP) levels in patients undergoing esophagectomy.

Methods: Forty-five patients were randomly divided into three groups: group A: 100 mg flurbiprofen axetil preoperative, 10 μg/kg fentanyl + 10 ml placebo postoperative; group B: 100 mg flurbiprofen axetil preoperative, 10 μg/kg fentanyl + 100 mg flurbiprofen axetil postoperative; group C: 10 ml placebo preoperative, 10 μg/kg fentanyl + 10 ml placebo postoperative. Postoperative analgesia was achieved by intravenous infusion containing flurbiprofen axetil and/or fentanyl at 2.0 ml/h (total volume, 100 ml) using infusion pumps. The β-EP was measured at preanesthesia (T(1)), the end of surgery (T(2)), 24 h (T(3)), and 48 h (T(4)) after surgery. Visual analog scale scores (VAS) at T3, T4 (at rest), and rescue analgesic tramadol requirement was recorded.

Results: The VAS of group B was significantly lower than group A and C (P < 0.01) at T(3) and T(4). The β-EP levels at T(2)-T(4) in group A did not differ significantly from those at T(1) (P > 0.05); however, the β-EP levels in group B at T(3)-T(4) increased significantly (P < 0.05), while those in group C increased at T(2) and decreased at T(4) (P < 0.05). The β-EP levels in group B at T(3) and T(4) were the highest as compared to its levels in groups A and C (P < 0.01). Tramadol consumption in group B was significantly lower than in groups A and C (P < 0.01).

Conclusion: These results show that flurbiprofen axetil enhances the analgesic effect of fentanyl associated with increase in β-EP levels.