Impact of Nuedexta on Bulbar Physiology and Function in ALS

Although advances in the management of bulbar dysfunction in ALS have been disappointing, recent interest has surfaced regarding the therapeutic potential of a pharmaceutical agent, Nuedexta (dextromethorphan HBr and quinidine sulfate), for the treatment of bulbar symptomology in individuals with ALS. Although Nuedexta received approval from the Food and Drug Administration (FDA) to target symptoms of pseudobulbar affect (PBA) in ALS; anecdotal reports of improvements in speech, salivation or swallowing were reported from Neurologists treating ALS individuals who were administered Nuedexta. Subsequently, a Phase II clinical trial was conducted that reported improvements in speech, swallowing and salivation following 30-days of Nuedexta treatment. One serious limitation of this study, however, is the fact that the primary outcome employed was a perceptual patient-report scale (PRO) (Center for Neurological Study Bulbar Function Scale, CNS-BFS), with no objective physiologic outcomes to confirm actual change in bulbar physiology. The absence of any objective clinical physiologic outcomes is particularly important when examining effects of Nuedexta, given that it contains selective serotonin reuptake inhibitors (SSRIs), or serotonergic antidepressants, that can impact the regulation of emotional expression, feelings of wellbeing and modulation of depression (all known to impact the response an individual will provide on a PRO measure). Furthermore, findings based on PRO's must be validated with studies that utilize objective physiologic outcomes of speech and swallowing function. Great excitement exists regarding the potential impact of Nuedexta on bulbar function in ALS with many neurologists prescribing Nuedexta to treat these symptoms in ALS patients. To date, however; no data exists to examine and determine the physiologic impact of Nuedexta on speech or swallowing physiology. These data are needed in order to validate the initial patient-reported outcomes of the Phase II clinical trial and to provide evidence-based guidance to the management of bulbar dysfunction in ALS.