Fig. 1.
Time course of acute antinociceptive effects with (A) cebranopadol and (B) fentanyl. Intravenous cebranopadol (A) or fentanyl citrate (B) was administered at the doses shown, and acute antinociceptive effects were measured over time using the low-intensity tail-flick model in rats (n = 10 per group). Tail withdrawal latency is expressed as a mean percentage of the maximum possible effect. Error bars show SD (either positive or negative). Dashed lines indicate no effect (0%). *P < 0.05, drug versus vehicle (two-way ANOVA with post hoc Bonferroni test).