Medication Overuse Headache

Abstract

Medication overuse headache (MOH) is defined in the latest ICHD-3 criteria as a secondary headache caused by worsening of a pre-existing headache (usually a primary headache) owing to overuse of one or more attack-aborting or pain-relieving medications. MOH can be debilitating and results from biochemical and functional brain changes induced by certain medications taken too frequently. Various risk factors some modifiable, other non-modifiable (Multiple Gene Polymorphisms) have been hypothesised in MOH. Psychiatric co-morbidities in MOH are noticeably (anxiety and depression) found to be co morbid disorders by more than chance. This has to be managed effectively along with treatment strategies for MOH for efficacious response to withdrawal treatment. Ample literature and clinical evidence shown in prospective trials, that withdrawal therapy is the best treatment for MOH. The mainstay of MOH treatment is not only to detoxify the patients and to stop the chronic headache but also, most likely, to improve responsiveness to acute or prophylactic drugs. Studies advocating prophylactic treatment with good response to mainly topiramate and OnabotulinumtoxinA do exist, less prominent for prednisolone, however, not recommended for every patient. Management may be complex and must be done via MDT approach with involvement of specialists when needed along with incorporating adequate treatment of acute withdrawal symptoms, educational and behavioural programs to ensure patient understanding of the condition and compliance. There are arguments on either sides of inpatient and outpatient withdrawal for MOH patients dependent heavily on the individual circumstances i.e. patient’s motivation, the duration of the overuse, the type of overused drugs, possible previous history of detoxification failures and co morbidities. Treatment trials are still required to determine for clinicians the best evidence-based approach for helping these patients break their headache cycle.