A study found that the US Food and Drug Administration (FDA) approval of a combination of dextromethorphan hydrobromide and quinidine sulfate for the treatment of pseudobulbar affect (PBA) after studies in patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS) appears mostly prescribed in patients with dementia and/or Parkinson disease (PD).
Researchers assessed the prescribing patterns of dextromethorphan-quinidine, including trends in associated costs. They used two databases to conduct a population-based cohort study of 12,858 patients who filled a prescription for dextromethorphan-quinidine over the study period from 2010-2017. The primary endpoints were defined as the proportion of patients prescribed dextromethorphan-quinidine with a diagnosis of MS, ALS, or dementia and/or PD, as well as the number of patients with a history of heart failure, which is a contraindication of the drug. Data analysis took place from December 2017, through August 1, 2018.
According to the results, 13.3% of patients had a history of heart failure, and few patients had a diagnosis of MS (8.4%) or ALS (6.8%); instead, most (57.0%) had a diagnosis of dementia and/or PD.
“Despite approval by the FDA for pseudobulbar affect based on studies of patients with ALS or MS, dextromethorphan-quinidine appears to be primarily prescribed for patients with dementia and/or PD,” the researchers concluded.
The findings were published in JAMA Internal Medicine.
Keywords: amyotrophic lateral sclerosis, multiple sclerosis, pseudobulbar affect