APETx2 has potent but highly variable antihyperalgesic activity in the FCA rat model of unilateral inflammatory pain. Mean (±SEM) paw pressure thresholds (PPT values), mean (±SEM) change in paw pressure thresholds (ΔPPTs) and mean (±SEM) change in PPT area under the curve (ΔPPT AUCs) for the ipsilateral (A, C, E) and contralateral (B, D, F) hindpaws of FCA rats following administration of single 100 μL intra‐plantar bolus doses of 0.05% RSA (vehicle control) (n = 10), morphine (Mor) at 700 nmol (n = 16), APETx2 at 0.03 pmol (n = 10), 0.1 pmol (n = 15), 1.1 pmol (n = 15), 3.3 pmol (n = 15) and 11 pmol (n = 16). PPTs were measured at time 0 (pre‐dosing) and at 30, 45, 60, 75, 90, 120 and 180 min post‐dosing. The dotted line in (A) indicates the PPT from the contralateral hindpaw. *P < 0.05, significantly different from vehicle; one‐way ANOVA.