Publication:

Evaluation of anti-nociceptive effect of venlafaxine in experimental animal model of mice

Background Pain is an unpleasant sensation with varying subjective experience. Its management is always challenging for physicians particularly in case of chronic pain. Chronic pain and depression usually co-exist due to poor quality of life and increase in health care costs posing an individual to suffer from depression. Anti-depressants for pain management are being used successfully using since years. In this study venlafaxine, a newer anti-depressant drug was evaluated for anti-nociceptive activity, tail immersion test an analgesic animal model of albino mice.

Methods Randomly selected albino mice of either sex with reaction time of <6 seconds were included in the study and divided into 7 groups with 6 mice in each group. Grouping was done based on the drug received i.e., venlafaxine 15, 30 and 60 mg/kg, tramadol 10 and 20 mg/kg, control group (normal saline) and combination group venlafaxine 15 mg/kg+tramadol 10 mg/kg. Drugs were administered by intra-peritoneal route.

Results Venlafaxine (30 and 60 mg/kg), tramadol (20 mg/kg) and combination group venlafaxine (15 mg/kg+tramadol 10 mg/kg) has shown significant (p<0.001) increase in tail withdrawal latency compared to control group (normal saline) by tail immersion test. Venlafaxine potentiated anti-nociceptive activity of tramadol on concomitant administration with tramadol. Venlafaxine at 60 mg/kg has comparable anti-nociceptive effect to tramadol at 20 mg/kg.

Conclusions Venlafaxine at doses of 30 and 60 mg/kg is having anti-nociceptive effect, but less potent than tramadol.