Tramadol Potentiates Vasopressin Induced Analgesia in Albino Mice

The effect of centrally acting opioid analgesic Tramadol on vasopressin induced analgesia was evaluated in Swiss albino mice. Analgesia was evaluated in the mice using tail clip and writhing test techniques. Animals were divided into control and test groups (n=6).Arginine vasopressin (12 µg/kg i.p) and its synthetic analogue, Terlipressin (300 µg /kg i.v) injected in the mice produced analgesia by increasing the latency period by 131.6% and 53.5% respectively and reduced the acetic acid writhing by 45.85 % and 13.51 % respectively. Pretreatment with Tramadol (10 mg/kg i.p) potentiated the analgesic action of vasopressin and terlipressin and increased the latency period and reduced the acetic acid induced writhings respectively. This study suggests that Tramadol can be combined with vasopressin for enhanced analgesic effect