BASH Guideline

In patients with migraine or tension-type headache, regular frequent use of acute treatment can result in exacerbation of the pre-existing primary headache (Diener & Dahlof, 1999).

Medication overuse headache (MOH) is classified as a chronic headache disorder. The headache occurs on more than 15 days a month for at least 3 months, affecting between 1-2% of the general population and, up to 20-50% of the chronic headache population (Castillo et al., 1999; Feigin et al., 2017; Scher et al., 1997; Stovner et al., 2007; Wang et al., 2000; Westergaard et al., 2014).

MOH has been recognized since the 1940s and is a worldwide issue resulting from an interaction between frequently used acute headache medication in a susceptible patient (Bahra et al., 2003; Wolfson & Graham, 1949).

Majority of patients improve on withdrawal of the overused medication (Anderson, 1975; Peters & Horton, 1951; Rowsell et al., 1973; Saper, 1987; Wainscott et al., 1974).

All medications used to treat an acute headache can result in medication overuse headaches. Triptans, opioids and combination analgesics are likely to result in development of MOH more rapidly (treatment taken on 10 days or more per month) as compared to simple analgesics such as paracetamol (treatment taken on 15 days or more per month) (Diener & Dahlof, 1999; Kaube et al., 1994; Limmroth et al., 2002; Limmroth et al., 1999; Mathew et al., 1990).

MOH occurs primarily in individuals with migraine or tension type headache and is generally of the same phenotype (Limmroth et al., 2002).

Overuse of triptans has been shown to cause MOH faster and with fewer doses compared with analgesics. The average interval between the first intake and daily MOH was 1.7 years for triptans, 2.7 years for ergots and 4.8 years for analgesics (Limmroth et al., 2002).

Patients must provide details of their usage of both prescription medications and of treatments taken over the counter.

Clinicians must specifically ask how many days in a month the patient takes medication for treating the acute headache and preferably correlate this with a headache diary.

In patients with a history of migraine or tension type headaches pain killer medication taken regularly for non-headache pain, such as joint or back pain, can result in medication overuse headaches (Bahra et al., 2003; Lance et al., 1988).

The association between analgesic overuse and chronic pain is strongest for chronic migraine (odds ratio of 10.3) (Zwart et al., 2004).