并降低曲马多使用剂量。提示曲马多与电针合用是一种治疗慢性痛的有效方法Objective:To investigate the antinociceptive effects of chronically using different dose of tramadol and the effect of tramadol on acupuncture analgesia in arthritis rats. Methods: SD rat arthritis model was established by injection of complete Freund's adjuvant 0.05 mL into the left ankle joint. The paw withdrawal latency (PWA)was detected with a radiant heat algesimeter. The difference between PWA of the inflammatory side and the healthy side was used as the hyperalgesia score. By using paw withdrawal latency to radiant heat stimulation and hyperalgesia score as the endpoint of nociceptive test
5 mg·kg -1 ·d -1
10 mg·kg -1 ·d -1 and 20 mg·kg -1 ·d -1 tramadol and 1 mL·kg -1 ·d -1 0.9% normal saline (NS) were respectively administrated intraperitoneally
once everyday and continuously for ten days. The changes of hyperalgesia score were observed 24 hr after drug administration everyday following i.p. 10 mg ·kg -1 ·d -1 tramadol
electroacupuncture (EA)
EA combined with i.p.10 mg·kg -1 ·d -1 tramadol and i.p. 1 mL·kg -1 ·d -1 0.9% NS (4 groups)
once everyday for ten days. Results: I.p. 5 mg·kg -1 ·d -1 tramadol for ten days did not show any effect ( P > 0.05) . I.p.10 mg·kg -1 ·d -1 tramadol for nine days
i.p. 20 mg·kg -1 ·d -1 for six days and using EA for eight days elevated hyperalgesia score significantly in comparison with NS group ( P <0.05~ 0.01) . Then i.p.10 mg·kg -1 ·d -1 tramadol combined with electroacupuncture for four days
hyperalgesia score was elevated significantly in comparison with NS group ( P <0.05~0.01) and with EA group ( P <0.05). Conclusion: The results show that tramadol has dose relative antinociceptive effect
and tramadol can enhance the analgesic effect of acupuncture under lower dose
suggesting that combination of acupuncture with tramadol is one of the effective treatment methods for chronic pain.