Assessment of general activity and anxiety-like behavior in mice following tramadol and meloxicam administration for managing immediate post-operative pain

Abstract

After analgesic administration, we evaluated general activity in the Open-Field and anxiety-like behavior in the Elevated Plus Maze of vasectomized mice. We divided C57BL/6J male mice into eight groups: saline, three non-operated control groups treated with 10 mg/kg meloxicam, 20 mg/kg tramadol, or both intraperitoneally, and four vasectomized mice groups treated with the same analgesic protocol as the control groups. One group of vasectomized mice received both treatments and an additional 10 mg/kg lidocaine at the incision site. We conducted the vasectomy via scrotal approach under isoflurane inhalation anesthesia and performed behavioral tests after full anesthesia recovery. Mice treated with meloxicam demonstrated low ambulation, spontaneous activity, and rearing frequency. Mice treated with tramadol showed spontaneous behavior compared with the saline control. Due to behavior changes demonstrated by meloxicam controls, we were unable to identify whether meloxicam provided adequate analgesia. Vasectomized mice treated with tramadol showed general activity behavior similar to their control but displayed significantly less rearing, suggesting that they were under potential signs of pain or discomfort. In conclusion, the Open Field test and the Elevated Plus Maze can usefully pre-evaluate analgesic protocols to identify possible interference caused by adverse drug effects. For future directions, an appropriate regimen of meloxicam and tramadol for enhancing mice welfare post vasectomy should be better investigated.