Given recent findings with combinations of CB1 receptor antagonist/inverse agonists (rimonabant, AM251) and the opioid receptor antagonist naloxone (Tallett et al., 2008b; 2009a), it was of particular interest to determine whether acute co-treatment with sub-anorectic doses sibutramine and rimonabant would (a) significantly reduce food intake and feeding behaviour (via additive or synergistic interaction) and/or (b) lead to a reduction/elimination of rimonabant-induced scratching and grooming (via infra-additive/antagonistic interaction).