Objective: To evaluate the dose-response analgesic effect of metformin in an acute pain event in rodents. Materials and methods: Eighty (80) mice were used. The analgesic effect was evaluated using the abdominal writhing test in mice. Eight (8) groups of 10 mice each were formed: one diclofenac 8 mg/kg group, one tramadol group, one target group, and five experimental groups of metformin at doses of 50, 100, 150, 200 and 250 mg/kg. For the statistical analysis, the D'Agostino-Pearson test, one-tailed ANOVA test, Tukey's test, and Pearson's correlation coefficient were used. Results: The D'Agostino-Pearson normality test revealed a p-value < 0.05 in all groups. The ANOVA test showed a p-value < 0.0001. The Tukey's range test obtained a p-value < 0.05 between the target group and metformin groups at all doses, and between the diclofenac group and metformin groups at doses of 100, ...

This work was partially supported by CONCYTEC (Peru) trough the project contract 169-2006-OAJ and ANPCyT (Argentina) PICT 33973. The authors are in debt with the reviewers for their useful suggestions to improve this paper.