Fralick M, et al. - Researchers investigated dextromethorphan-quinidine prescription patterns, including trends in associated costs, following the US Food and Drug Administration’s (FDA) approval for pseudobulbar affect. Dextromethorphan-quinidine seems to be mainly prescribed for patients with dementia and/or Parkinson disease (PD), even with FDA approval for pseudobulbar affect based on studies of patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS).

Methods

• This population-based cohort study used data from two commercial insurance databases (Optum Clinformatics Data Mart and Truven Health MarketScan) for patients prescribed dextromethorphan-quinidine.
• The data set for the Medicare Part D Prescription Drug Program was used to assess numbers of prescriptions and total reported spending by the Centers for Medicare & Medicaid Services.
• Patients were eligible if they were prescribed dextromethorphan-quinidine from October 29, 2010, when the drug was approved, through March 1, 2017, for Optum and December 31, 2015, for Truven.
• Data were analyzed between December 1, 2017 and August 1, 2018.
• Main outcomes and measures included 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 (a contraindication for the drug).

Results

• Twelve thousand, eight hundred fifty-eight patients filled a prescription for dextromethorphan-quinidine during the study period in the commercial health care databases; mean (SD) age was 66.0 (18.5) years, 66.7% were women, and 13.3% had a history of heart failure.
• In merging results from both databases, a small portion of patients were diagnosed with either MS (8.4%) or ALS (6.8%); the majority (57.0%) were diagnosed with dementia and/or PD.
• The number of patients prescribed dextromethorphan- quinidine in the Medicare Part D database increased 15.3-fold from 3,296 in 2011 to 50,402 in 2016.
• Centers for Medicare & Medicaid Services reported expenditure on this drug from $3.9 million in 2011 to $200.4 million in 2016.