There were no significant pharmacogenetic effects for OPRK1^2 on stimulation (β = 0.071, SE = 0.203, t = 0.35, p = 0.73) or craving (β = 0.046, SE = 0.147, t = 0.31, p = 0.76). For the other kappa marker (OPRK1^1), there was a trend-level pharmacogenetic effect on sedation (β = −0.41, SE = 0.215, t = −1.92, p = 0.055), but no such effects on stimulation (β = −0.0007, SE = 0.232, t = −0.00, p = 0.99), or craving (β = 0.22, SE = 0.169, t = 1.30, p = 0.196).
