Medication Overuse Headache

Background: Medication overuse headache (MOH) is one of the highly disabling headache disorder and affects about 1% of the population of the world. It is associated with the development of headache for 15 days or more, with consumption of acute symptomatic medications for 10-15 days (depending on the class of drug, like, simple analgesics, triptans, and opioids) in a month, used for relief of headache for three or more months, in a known patient of primary headache disorder. Objective: The aim of this study was to review the topic of MOH and present the details of this disorder with an emphasis on recent updates in the field of pathophysiology and treatment. Material and Methods: Literature search was performed in the PubMed/MEDLINE and Cochrane database with appropriate keywords and relevant full-text articles were reviewed for writing this article. Results: Over the years, the concept of MOH has evolved, although the exact pathophysiology is still being explored. In a susceptible individual interplay of genetics, change in pain pathways, changes in areas of the brain associated with the perception of pain, and changes in the neurotransmitters have been implicated. It has to be differentiated from other secondary chronic daily headache disorders, by a careful history, targeted examination, details of intake of medications. Treatment predominantly involves patient education, removal of the offending agent, and initiation of prophylactic medications for primary headache disorder in the outpatient or inpatient services. Conclusions: MOH is a secondary headache disorder, which should be considered in any chronic headache patient. There are various pathophysiological mechanisms attributed to its development. Management includes educating the patients about the disorder, detoxification, and prophylactic therapy.