deudextromethorphan + quinidine

**deudextromethorphan + quinidine** is a fixed-dose combination drug that contains deudextromethorphan (a deuterated form of dextromethorphan) and quinidine. It is used primarily in the treatment of pseudobulbar affect (PBA), which presents as sudden, uncontrollable episodes of laughing or crying seen in neurological conditions like amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS)[1][2][5]. Deudextromethorphan acts as a sigma-1 receptor agonist, a serotonin–norepinephrine reuptake inhibitor, and an NMDA receptor antagonist. Quinidine is included at a low dose to inhibit CYP2D6, thereby increasing plasma concentrations of deudextromethorphan[2][3][5]. The precise mechanism by which this combination benefits PBA is unknown, but these combined actions are thought to modulate emotional expression and neurotransmitter function in the CNS[3][5].

Brand names

Nuedexta

Other names

deudextromethorphan and quinidine