Medication Overuse in Chronic Daily Headache

The frequent or regular intake of medication to treat acute headache episodes can lead to an increase in headache frequency and finally to a transition from episodic to chronic headache. Many patients with chronic headache take abortive medication on a daily basis. Medication overuse headache (MOH) is defined by the International Classification of Headache Disorders as a headache in patients with a pre-existing primary headache disorder (e.g., migraine or tension-type headache) occurring on ≥15 days per month for >3 months. Also, these primary headache disorders occur in association with overuse of medication for acute or symptomatic headache treatment. The prevalence of MOH in the general population is around 1%. MOH is more common in people with chronic migraine and chronic daily headache than in patients with episodic migraine. The phenotype of the headache in MOH depends on the initial primary headache and the type of overused acute medication. Treatment of MOH occurs in three stages. First, we educate patients about the relationship between frequent intake of acute headache medication and MOH to reduce intake of acute medication. In a second step migraine prevention should be initiated in chronic migraine (topiramate or onabotulinumtoxinA in migraine) or amitriptyline in chronic tension-type headache. In patients who fail to cease overuse of overused medication with preventive therapy, then detoxification occurs on an outpatient basis or in a day hospital or inpatient setting, depending on severity and comorbidities. The success rate of treatment is around 50–70%, with higher relapse rates in patients with opioid overuse. Patient education and continuity of care in the follow-up period reduce relapse rates.