AM6538, a long-acting, high-affinity, and pseudo-irreversible cannabinoid antagonist structurally analogous to rimonabant, is a valuable tool for assessing the apparent efficacy of cannabinoid partial and full agonists. It also holds potential for future investigations requiring temporary reductions in cannabinoid receptor availability[1].

AM6538 acts as a cannabinoid antagonist, targeting CB1 receptors within HEK-293 cells, exhibiting wash-resistant binding properties[1].

AM6538 (1~10 mg/kg) effectively antagonizes the antinociceptive effects of cannabinoid agonists in mice[1], with 10 mg/kg indicating partial recovery of AM4054 effects. It decreases tau values for all cannabinoid agonists dose-dependently, reducing receptor availability and exerting lasting antagonism, significantly affecting tetrahydrocannabinol dose-effect function up to 7 days post-treatment[1].