Figure 7.

The effects of nalmefene on cocaine‐alcohol interactions (and II): before cocaine administration. Nalmefene was injected s.c. 20 min before the administration of cocaine (20 mgKg, i.p.). Nalmefene administered 18 h before alcohol self‐administration was not effective in reducing alcohol responses or in preventing cocaine‐induced increases in alcohol responses. Nalmefene was not effective in preventing cocaine‐induced locomotor sensitization. (A) Data represent the mean ± SEM of the accumulated or day by day operant alcohol responses to 20% v·v⁻¹ alcohol (n = 11, 7, 11, 11 per group). * P < 0.05 compared with the vehicle group; # P < 0.05 compared with the nalmefene group. (B) Motor activity, mean ± SEM of the accumulated beam breaks for the 30 min after cocaine administration (n = 11, 7, 11, 11 per group). *** P < 0.001 compared with the vehicle group; ### P < 0.001 compared with the nalmefene group.