NASHVILLE, TENN. – , pointing to a major shift to newer, costlier, brand-name drugs – a trend in spending that may not be sustainable, the lead author of a study of drug costs said.
The study, presented at the 2022 annual meeting of the American Epilepsy Society, evaluated claims data for prescriptions for common antiseizure medications in the Medicare Part D and Medicaid databases from 2012 to 2020. The study excluded gabapentin and pregabalin because they’re frequently prescribed for other indications in addition to epileptic seizures.
“We found that third-generation medications, even though they accounted for the smallest percentage of claims in 2020, took up the most astronomical portion of the money that was spent,” lead author Deepti Zutshi, MD, an associate professor of neurology at Wayne State University in Detroit, said in an interview.
The study found that Medicare Part D spending on antiseizure medications increased from $1.16 billion in 2012 to $2.68 billion in 2020. In Medicaid, spending followed a similar trend, increasing from $973 million in 2012 to $1.05 billion in 2020.
Analyzing Medicare/Medicaid claims data
The study categorized drugs two ways: by brand or generic; and by first, second, or third generation, Dr. Zutshi said. First-generation drugs include medications such as phenobarbital, phenytoin, valproate, and carbamazepine. Second-generation medications were released in the early 2000s and include medications such as lamotrigine and levetiracetam. Examples of third-generation drugs include lacosamide, vigabatrin, clobazam, and perampanel.
Prescribers shifted significantly to third-generation treatments, Dr. Zutshi said. In Medicare Part D, the total spent on third-generation antiseizure medications went from $124 million in 2012 to $1.08 billion in 2020, representing a quadrupling in percentage of costs, from 10.7% to 40.4%. The total number of claims for third-generation antiseizure medications was 240,000 in 2012 (1.3%) and 1.1 million in 2020 (4.4%).
When looking at brand versus generic, the total spent on brand-name antiseizure medications increased nearly threefold from $546 million in 2012 to $1.62 million in 2020, with the share of all funding spent on brand-name antiseizure medications jumping from 46.8% to 60.2%. However, the proportion of total claims for branded antiseizure medications actually dropped, from 9.24% in 2012 to 6.62% in 2020.
Medicaid trends followed a similar pattern. Third-generation antiseizure medications accounted for 1.7% of total claims in 2012 and 6% in 2020. Spending on third-generation antiseizure medications grew nearly eight times: from $147 million, or 15.1% of funding spent on antiseizure medications, in 2012 to $1.15 billion in 2020, a 56.1% share of costs. The total spend of branded antiseizure medications in Medicaid was $605 million in 2012 and $1.46 billion in 2020 – a jump in the share of total spending from 62.2% to 71.3%. As in Medicare Part D, the percentage of total claims for branded antiseizure medications in Medicaid also dropped from 2012 to 2020, from 12.1% to 6.8%.