Abuse liability of dextromethorphan and its combinatory formulation dextromethorphan/bupropion: a pharmacologic perspective.
Expert opinion on drug metabolism & toxicology January 1, 2026 Yang Jing Zheng, Christine E Dri, Sabrina Wong et al.
Dextromethorphan/bupropion (DXM/BUP) received breakthrough FDA approval in August 2022 as a rapid-acting antidepressant. DXM/BUP is a noncompetitive NMDA receptor antagonist and sigma-1 receptor agonist, combined with bupropion, a norepinephrine/dopamine reuptake inhibitor and CYP2D6 inhibitor. DXM alone has long been misused due to its metabolism into the psychoactive metabolite dextrorphan (DXO). The article discusses the pharmacodynamics and pharmacokinetics of DXM and DXO, highlights the abuse potential of DXM alone, and presents preclinical, clinical, and pharmacovigilance findings that support reduced abuse liability of DXM/BUP. The formulation demonstrates clinically meaningful improvement within one week of initiation. Given its safety, efficacy, and novelty, this glutamatergic modulator is a promising candidate for global approval. Future research should examine its potential in bipolar depression and trauma-associated MDD.