Medication Overuse Headache - Classification

Classification

Medication overuse headache is a recognized ICDH classification. Over the years different sets of diagnostic criteria have been proposed and revised by the major experts of headache disorders. The term MOH first appeared only in the 2004, among the secondary headaches in the 2nd edition of the International Headache Society’s Classification (International Classification of Headache Disorders – II edition, ICHD-II) with the aim of emphasising excessive drug intake as the basis of this form of headache. The two subsequent revisions of the diagnostic criteria for MOH (2005 and 2006) refined and extended the definition of this condition on the basis of both its chronicity (headache on more than 15 days/month for more than three months) and the different types of drugs overused thereby identifying the main types of MOH. In the case of ergotamine, triptans, opioids and combination medications in particular, intake on > 10 days/month for > 3 months is required, whereas simple analgesics are considered overused when they are taken on > 15 days/month for >3 months.