- 57% of patients prescribed the combination of dextromethorphan hydrobromide and quinidine sulfate (Nuedexta) have dementia and/or Parkinson’s disease.
Why this matters
- Combination's approval by FDA for treatment of pseudobulbar affect in 2010 was based on studies in patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS).
- Diagnoses in 12,858 commercially insured patients filling prescription for dextromethorphan-quinidine:
- MS: 8.4%.
- ALS: 6.8%.
- Dementia and/or Parkinson’s disease: 57.0%.
- Patients with contraindications/contraindication indicators:
- 13.3% had history of heart failure.
- 38.3% filled prescription for QT-prolonging medication within 30 days.
- Prescribing providers:
- General internists: 25.4%.
- Neurologists: 22.8%.
- Family practitioners: 17.5%.
- Psychiatrists: 9.8%.
- Geriatricians: 5.1%.
- Nurse practitioners: 4.8%.
- Physician assistants: 2.5%.
- Based on Medicare Part D, Centers for Medicare & Medicaid Services data for 2011-2016:
- Number of patients prescribed medication increased 15.3-fold (from 3296 to 50,402).
- Spending on medication increased 51.4-fold (from $3.9 million to $200.4 million).
- Population-based cohort study using data from 2 commercial insurance databases, Medicare Part D, Centers for Medicare & Medicaid Services.
- Main outcomes: diagnoses; heart failure history.
- Funding: Laura and John Arnold Foundation; others.
- Reasons for prescribing unknown.
- Possible underestimation of prescribing to patients with dementia/Parkinson’s disease.
- Rebates, discounts not reflected in costs.