Probable medication-overuse headache: the effect of a 2-month drug-free period.

Abstract

To describe the emerging profile of headache frequency following a 2-month drug-free period in patients with medication overuse. All patients treated and discharged from Danish Headache Center in 2002 and 2003 had prospectively filled out a diagnostic headache diary on a daily basis. For patients with probable medication-overuse headache (MOH), the authors determined headache frequencies before and after medication withdrawal from these prospective recordings. Among 1,326 patients, 337 had probable MOH. Two hundred sixteen patients who stayed medication-free for 2 months were eligible. Overall, 45% of the patients improved, 48% had no change, and 7% had more headaches. Median age was 48 years, and male/female ratio 1:2.7. The relative reduction in headache frequency varied considerably with a 67% median reduction in migraine, 0% in tension-type headache (TTH), and 37% in patients with both migraine and TTH (MT). Comparing the diagnostic groups, the relative reduction in frequency differed between migraine and TTH (p < 0.001) and between MT and TTH (p < 0.01). Triptan/ergot overusers improved the most (p < 0.0001). The difference between MT and TTH remained significant when triptan/ergot overuse was controlled (p < 0.05). These data demonstrate the benefit of withdrawal in already established medication overuse and support the existence of medication-overuse headache as a clinical entity.