A comparative study of antinociceptive effects of Tapentadol, amitriptyline and combination of both in albino rats

Objective: The aim of the study was to investigate the possible antinociceptive effects of combination of Tapentadol and Amitriptyline in comparison to the single drugs. Materials and Methods: After approval from Animal Ethics Committee, a total of twenty four (n = 24) healthy male albino rats were divided into four groups of six rats in each. Group Iwas control,Gr. II tapentadol treated,Gr. III amitriptyline treated and Gr. IV treated with both tapentadol and amitriptyline. The test drugs administered thirty minutes prior to the procedure once at weekly intervals (on day 0, 7, 14, 21 and 28) for up to 28 days. Haffners tail clip and formalin test were conducted to evaluate the antinociceptive effects. Results: In both animal test models the antinociceptive effects observed from the combination of tapentadol and amitriptyline was greater than that produced by tapentadol and amitriptyline alone. Conclusion: From the results obtained in this study, we can conclude that coadministration of tapentadol and amitriptyline showed much greater antinociceptive effects than either drug singly . Thus, in combined form they can potentiate each others action via multifactorial mechanism.