Changes in the Use of Brand Name and Generic Medications and Total Prescription Cost Among Medicare Beneficiaries With Epilepsy.

First-generation and enzyme-inducing ASMs waned from 2008 to 2018. While brand name ASMs initially waned translating into lower costs and potentially higher value care, after 2010 brand name costs markedly increased due to increasing use of lacosamide plus a 277% increase in per-pill cost of brand name ASMs. Brand name ASMs represented a small minority of prescriptions, but the large majority of costs.