Transformed migraine and medication overuse in a tertiary headache centre--clinical characteristics and treatment outcomes.

Studies suggest that a substantial proportion of headache sufferers presenting to headache clinics may overuse acute medications. In some cases, overuse may be responsible for the development or maintenance of a chronic daily headache (CDH) syndrome. The objectives of this study are to evaluate patterns of analgesic overuse in patients consulting a headache centre and to compare the outcomes in a group of patients who discontinued medication overuse to those of a group who continued the overuse, in patients with similar age, sex and psychological profile. We reviewed charts of 456 patients with transformed migraine (TM) and acute medication overuse defined by one of the following criteria: 1. Simple analgesic use (>1000 mg ASA/acetaminophen) > 5 days/week; 2. Combination analgesics use (caffeine and/or butalbital) > 3 tablets a day for > 3 days a week; 3. Opiate use > 1 tablet a day for > 2 days a week; 4. Ergotamine tartrate use: 1 mg PO or 0.5 mg PR for > 2 days a week. For triptans, we empirically considered overuse > 1 tablet per day for > 5 days per week. Patients who were able to undergo detoxification and did not overuse medication (based on the above definition) after one year of follow-up were considered to have successful detoxification (Group 1). Patients who were not able to discontinue offending agents, or returned to a pattern of medication overuse within one year were considered to have unsuccessful detoxification (Group 2). We compared the following outcomes after one year of follow-up: Number of days with headache per month; Intensity of headache; Duration of headache; Headache score (frequency x intensity). The majority of patients overused more than one type of medication. Numbers of tablets taken ranged from 1 to 30 each day (mean of 5.2). Forty-eight (10.5%) subjects took >10 tablets per day. Considering patients seen in the last 5 years, we found the following overused substances: Butalbital containing combination products, 48%; Acetaminophen, 46.2%; Opioids, 33.3%; ASA, 32.0%; Ergotamine tartrate, 11.8%; Sumatriptan, 10.7%; Nonsteroidal anti-inflammatory medications other than ASA, 9.8%; Zolmitriptan, 4.6%; Rizatriptan, 1.9%; Naratriptan, 0.6%. Total of all triptans, 17.8%. Of 456 patients, 318 (69.7%) were successfully detoxified (Group 1), and 138 (30.3%) were not (Group 2). The comparison between groups 1 and 2 after one year of follow-up showed a decrease in the frequency of headache of 73.7% in group 1 and only 17.2% in group 2 (P < 0.0001). Similarly, the duration of head pain was reduced by 61.2% in group 1 and 14.8% in group 2 (P < 0.0001). The headache score after one year was 18.8 in group 1 and 54 in group 2 (P < 0.0001). A total of 225 (70.7%) successfully detoxified subjects in Group 1 returned to an episodic pattern of migraine, compared to 21 (15.3%) in Group 2 (P < 0.001). More rigorous prescribing guidelines for patients with frequent headaches are urgently needed. Successful detoxification is necessary to ensure improvement in the headache status when treating patients who overuse acute medications. Copyright Blackwell Publishing Ltd.