Samidorphan CAS# 852626-89-2

Samidorphan, also known as ALKS-33 and RDC-0313, is an opioid modulator. In preclinical studies, Samidorphan demonstrated potent and selective antagonism at the μ-opioid receptor (MOR) with a reported Ki of approximately 0.6 nM in radioligand binding assays, while exhibiting partial agonist activity at δ- and κ-opioid receptors. In rodent models, oral administration of Samidorphan effectively blocked opioid-induced analgesia in a dose-dependent manner, confirming functional MOR antagonism. Co-administration with olanzapine in rat and non-human primate models significantly attenuated olanzapine-induced weight gain without affecting the antipsychotic efficacy of olanzapine, indicating a modulatory role on opioid-mediated metabolic pathways.