Pharmacoepidemiology of drug abuse in headache patients: comparison between sufferers of medication-overuse headache and migraine

Chronic headache patients often overuse symptomatic drugs while episodic headache patients usually take drugs in a very cautious way. It is unknown if the differences between the two groups of headache sufferers concern only the amount or also the type of drug used. Our aim was to compare the pharmacological habit between medication-overuse headache (MOH) and migraine patients. Methods We compared a) all drugs that 138 MOH patients (F/M=5.3; mean age +DS: + years) consecutively admitted at the in-patient ward of the Headache Centre of the University of Modena and Reggio Emilia, were taking and b) all drugs that 78 migraine patients (F/M= 2.3; mean age +DS: + years) consecutively referred at the out-patient ward of the Centre. Data were collected by means a standardized clinical chart and recorded in an apposite database. The study was carried out between June 2004 and March 2005. Results There were great differences in the type of symptomatic medications used between MOH and migraine patients. In particular MOH patients used concomitantly more than one type of symptomatic: triptans 43.5%, NSAIDs 42%, association of indomethacin, prochlorperazine and caffeine (IPC) 14.5%, and weak opioid 10%. Migraine patients took: NSAIDs 56%, triptans 30%, IPC 5%, and other analgesic combinations 2.6%. In both groups most used drugs, respectively among NSAIDs and triptans, were nimesulide and sumatriptan. Fifty-eight per cent of MOH but only 20% of migraine patients were taking prophylactic treatments. More than 71% of MOH patients were using other medications, too: antihypertensive agents 27.5%, benzodiazepines 27%, antidepressants 23%, hormones 23%, antilipemic agents 7%, antiplatelet agents 6%. Among migraine patients 54% were using other medications, too: hormones 33%, antihypertensive agents 8%, antidepressants 10%, benzodiazepines 5%. Conclusions Even if MOH often evolves from migraine, our study indicates that pharmacoepidemiology of drug use was different between the two headache forms: MOH overused triptans more than NSAIDs and were poli-medicated; migraine patients for acute treatment took mainly NSAIDs, did not use weak opioid and overall took few other medications.