Dextromethorphan/quinidine for the treatment of pseudobulbar affect

Abstract

Objective: To evaluate the role of dextromethorphan/quinidine (DM/Q; Nuedexta™) in the treatment of pseudobulbar affect (PBA).

Data sources: A literature search of MEDLINE/PubMed (January 1966-June 2013) was conducted using search terms pseudobulbar affect, pathological laughing and/or crying, emotional lability, dextromethorphan, and quinidine.

Study selection and data extraction: English language clinical trials and case reports evaluating the safety and efficacy of DM/Q in PBA were included for review. Bibliographies of all relevant articles were reviewed for additional citations.

Data synthesis: PBA, a poorly understood disorder, is characterized by involuntary crying and/or laughing. In the past, antidepressants and antiepileptics have been used off-label with mixed results. Four clinical trials have evaluated the use of DM/Q for the treatment of PBA. Although the therapeutic outcomes with DM/Q have been positive, interpretation of the published evidence is limited by small sample size and short treatment duration.

Conclusions: Based on the data available, DM/Q may be a viable, short-term treatment alternative for PBA. Long-term safety and efficacy data are lacking.

Keywords: AD = Alzheimer's disease; AE = Adverse effect; ALS = Amyotrophic lateral sclerosis; Antidepressants; CNS-LS = Center for Neurologic Study Lability Scale; CYP = Cytochrome; DM/Q = Dextromethorphan/quinidine; Dextromethorphan; Emotional lability; FDA = Food and Drug Administration; ICD = International Classification of Diseases; MS = Multiple sclerosis; NMDA = N-methyld-aspartate; PBA = Pseudobulbar affect; PD = Parkinson's disease; PLACS = Pathological Laughing and Crying Scale; PLC = Pathological laughing or crying; Pathological laughing and crying; Pseudobulbar affect; Quinidine; SSRIs = Selective serotonin reuptake inhibitors; TBI = Traumatic brain injury; TCAs = Tricyclic antidepressants.