Effect of trifluoperazine on mechanical nociceptive threshold in the von Frey test. Trifluoperazine (0.3 mg/kg) was administered orally in intact rats. The von Frey test was performed immediately before (0 min) and at 30, 120 and 240 min after administration of trifluoperazine. Trifluoperazine did not affect mechanical nociceptive threshold in intact rats. Values are expressed as the mean ± SEM. of 8 animals. No statistical difference was identified (one-way ANOVA followed by Tukey-Kramer post-hoc test).