Features of medication overuse headache following overuse of different acute headache drugs

Objective: To investigate pharmacologic features such as mean critical duration until onset of medication-overuse headache (MOH) (MCDO), mean critical monthly intake frequencies (MCMIF), and mean critical monthly dosages (MCMD) as well as specific clinical features of MOH after overuse of different acute headache drugs, with a focus on newly approved triptans. Methods: In a prospective study 98 patients with MOH according to International Headache Society (IHS) criteria underwent standardized inpatient withdrawal from their medication. Patient diaries and structured interviews were used to calculate the MCDO, MCMIF, and MCMD for each substance group. Results: The MCDO was shortest for triptans (1.7 years), longer for ergots (2.7 years), and longest for analgesics (4.8 years). The MCMIF was lowest for triptans (18 single doses per month), higher for ergots (37), and highest for analgesics (114). Although patients overusing ergots and analgesics typically had a daily tension-type headache, patients with triptan-induced MOH were more likely to describe a (daily) migrainelike headache or an increase in migraine frequency. Conclusion: Overuse of triptans leads to MOH faster and with lower dosages compared with ergots and analgesics. Clinical features of MOH depend on the type of overused headache medication. Pharmacologic and clinical characteristics of triptan-induced MOH call for the renewal of the current IHS classification.