Is overuse of sumatriptan a problem? A population based study

Objective: Sumatriptan is highly efficacious in aborting acute attacks of migraine. Owing to recent reports of misuse of sumatriptan, we performed a study of its use in a Danish population. Methods: Data were retrieved from a prescription database covering a period of 27 months after release of the drug. Consumption was described by the defined daily dose (DDD) unit and total individual consumption during the period was calculated. Those who received more than one prescription for sumatriptan were classified according to peak use of sumatriptan into high (greater than or equal to 60 DDD/31 days) (n = 45), intermediate (30-59 DDD/31 days) (n = 127) and low (< 30 DDD/31 days) (n = 1423) consumption groups. Individual usage of other medication was described. Results: We identified 2,878 users of sumatriptan, of whom 1,283 (45%) only redeemed one prescription. The use of sumatriptan was highly skewed. The 1% heaviest users accounted for 20% of the total consumption. The median total individual consumption of sumatriptan was 500 DDD, 192 DDD, and 24 DDD in the three groups of multiple redeemers, respectively. Pronounced differences in the total amounts of opioids and ergot alkaloids used were also found, with the high peak consumption group being the heaviest consumers of all drug categories, although half of them had only received large doses of sumatriptan. Fifty seven % of high peak users redeemed more than 29 DDD of sumatriptan within one month of initiation of treatment. The 45 high peak users had received the bulk of their medication, largely in tablet formulation, from 31 prescribers. The data points to rebound headache as a plausible underlying mechanism, but incorrect use of sumatriptan for migraine prophylaxis is also a possibility. Overuse of sumatriptan has serious economic consequences and its long-term health effects are not known.