The amount of money people pay out-of-pocket for branded drugs to treat neurological diseases like multiple sclerosis (MS), Alzheimer's, and Parkinson's disease continues to rise, especially for MS drugs, according to a study published in the October 30, 2024, online issue of Neurology.

The study found that average out-of-pocket costs for drugs for MS increased by 217% over a nine-year period. Costs have dropped for medications where generic versions have been introduced.

"In some cases, the out-of-pocket cost to patients has increased much more than the total cost of the drug, indicating that patients are taking on a disproportionate amount of the burden of these cost increases," said study author Amanda V. Gusovsky, MPH, Ph.D. of The Ohio State University in Columbus.

"In other cases where generic drugs were introduced and the overall costs went down, the out-of-pocket costs to patients did not decrease, so they were not benefiting from these reductions."

For the study, researchers examined costs of drugs for five common neurological diseases from 2012 to 2021 using a large private health care claims database. The study involved 186,144 people with epilepsy, 169,127 with peripheral neuropathy, 60,861 with Alzheimer's or other dementia, 54,676 with MS and 45,909 with Parkinson's disease.

MS drugs had the largest increase in costs, with the average out-of-pocket drug cost increasing from $750 per year in 2012 to $2,378 per year in 2021. All MS drugs had increasing out-of-pocket costs.

"MS medication costs remain exceptionally high and pose a substantial financial burden to people with this devastating disease," Gusovsky said. "It's imperative that we develop policy solutions such as caps on costs, value-based pricing and encouraging production of generic drugs to address this issue."

The study found that the cost of several drugs for these diseases decreased by 48% to 80% in the years after a generic version of the drug was introduced.

Gusovsky said both neurologists and patients should consider the use of generic or biosimilar drugs where available to control costs. She noted that previous studies have shown that high costs can create burdens such as medical debt, skipping food or other essentials or not taking drugs as often as prescribed, which can possibly lead to complications and higher costs later.

A limitation of the study is that the data represents billed charges, which are an estimate of actual costs.