Adoption of rimegepant in Denmark: a register-based study on uptake, prescribing patterns and initiator characteristics

Background: Rimegepant, an oral calcitonin gene-related peptide (CGRP) receptor antagonist, is the first drug within its class approved for both acute and preventive treatment of migraine. This study examines its uptake in Denmark. Methods: Using nationwide healthcare registry data, we analyze trends in rimegepant prescriptions from its introduction in October 2022 to December 2024. Parameters assessed include demographic and clinical characteristics of users, temporal trends in drug use, treatment adherence, and concomitant use of other migraine therapies. Results: By December 2024, over 140,000 defined daily doses (DDDs) of rimegepant had been dispensed in Denmark, primarily among females (88%), with a users’ median age of 45 years. Most initiators had prior experience with triptans (79%) or NSAIDs (38%) for migraine treatment and 69% met criteria for medication overuse before initiation. Concomitant use of triptans (63%) and NSAIDs (17%) remained common, but a substantial decline in the overuse of acute headache medications was observed after rimegepant initiation. Early discontinuation was very common, with 45% of initiators filling only one prescription. Among the 55% who continued treatment, the most substantial drop occurred within the first 90 days, followed by a more gradual decrease over time. Conclusions: The study highlights the rapid uptake of rimegepant in Denmark, especially among middle-aged females with a history of triptan use and medication overuse. While rimegepant was associated with a reduction in acute medication overuse, early discontinuation rates suggest barriers to sustained use, potentially influenced by cost, efficacy, or patient preferences. There is a need for strategies to optimize long-term adherence and access to rimegepant in clinical practice.