Figure 12.

Anti-hyperalgesia and analgesia.

Notes: Placebo-corrected differences for the active treatments in secondary hyperalgesia areas (Δ2HA[%], upper panel), pain-ratings during the heat injury (ΔPHI[%], middle panel), and electrical pain thresholds (ΔEPTo[%], lower panel). Columns are median (IQR). The anti-hyperalgesia/analgesia ratios (Δ2HA/ΔPHI and Δ2HA/ΔEPTo) for the four opioids relative to placebo.

Abbreviations: Δ2HA(%), secondary hyperalgesia area relative to placebo; ΔPHI(%), heat injury relative to placebo; ΔEPTo(%), electrical pain tolerance relative to placebo; 2HA/PHI, ratio (secondary hyperalgesia/heat injury) relative to placebo; 2HA/EPTo, ratio (secondary hyperalgesia/electrical pain tolerance) relative to placebo; IQR, inter-quartile range