Drug-induced headache: long-term follow-up of withdrawal therapy and persistence of drug misuse.

Patients suffering from migraine, tension-type headache (TTH), or combined headache (CH) are at risk of developing drug-induced headache (DIH) due to regular use of analgesics, ergot alkaloids, and triptans. The aim of our study was to determine (1) the clinical features of DIH, (2) the outcome of withdrawal therapy using high methodological standards, and (3) predictors which could explain the high relapse rate (more than 40%) after a previously successful withdrawal therapy. We retrospectively reviewed 103 patients with migraine or TTH who underwent withdrawal therapy between 1994 and 1998. The long-term follow-up (2-4 years after therapy) was conducted by phone and by specially trained psychologists using a structured interview which enclosed characteristics of headache and medication behavior as well as patients global assessment of success. Complete sets of data were available from 83 patients (38 migraine, 26 TTH, 19 CH). The most frequently abused drugs were caffeine-combined analgesics (24%), followed by caffeine-combined ergotamines (19%), pure ergot alkaloids (17%), and monoanalgesics (17%). 48.5% of the patients suffered an abuse relapse within 4 years and developed the complete features of DIH again. Analgesic and ergot alkaloid combinations with caffeine lead significantly more often to a relapse. A long-term successful therapy is connected with a significant reduction of the frequency of headache attacks. Under relapse conditions, the patients reached their former headache frequency level. The data show a higher relapse rate than previously assumed and that certain substance groups bear a higher relapse risk. Copyright 2001 S. Karger AG, Basel