Medication overuse headache is a chronic headache that occurs in people with a pre-existing primary headache, such as migraine or tension-type headache, following overuse of any kind of acute headache medications. In this update, the author provides an update on the definition, pathophysiology, clinical aspects, and treatment strategies of this headache type.
• Medication overuse headache is a common and disabling disorder that affects 1% to 2% of the general population. It is extremely important to recognize and treat this condition.
• Overuse of any kind of acute headache medications can lead to the development of medication overuse headache.
• In general, treatment of medication overuse headache requires a multidisciplinary setting and includes education of patients, discontinuation of the overused medication, and initiation of preventive treatment. Large randomized controlled trials are underway to determine the best treatment strategy for medication overuse headache.
Historical note and terminology
Chronic headache following overuse of acute migraine drugs was described first by Horton and Peters (53). They reported 52 patients with migraine who took ergotamine daily and developed daily headache, and the authors noted improvement after the ergotamine was withdrawn.
The International Headache Society originally defined drug-induced headache as chronic headache occurring on 15 or more days a month following overuse of any kind of acute headache drugs (50). This, however, was based on experience with overuse of analgesics and ergots only and did not cover the triptan-induced medication overuse headache. After triptans were introduced, it became clear that they can also lead to medication overuse headache (58; 66; 65). The revised second edition of the classification criteria of the International Headache Society introduced the term “medication overuse headache,” which replaced previous terms such as “drug-induced headache,” “analgesic-induced headache,” and “rebound headache.” It further differentiated between medication overuse headaches induced by analgesics, ergots, triptans, and opioids (74). In 2006, an expert board consensus paper introduced of broader concept of medication overuse headache in which the diagnosis of medication overuse headache is based on the headache frequency (greater than or equal to 15 days a month) and overuse of headache medication but does not require the headache to improve after withdrawal (73). In 2013, the International Headache Society published the third beta version of the classification criteria, and the ICHD-3 diagnostic criteria was published in 2018. In the ICHD-2, medication overuse headache excluded a concomitant diagnosis of chronic migraine. However, according to the ICHD-3 Beta, as well as the ICHD-3 criteria, because it is unknown whether the overuse of medication is the cause or consequence in an individual case, the patient will receive a diagnosis of both chronic migraine and medication overuse headache when both criteria are met (51).
In the ICHD-3, medication overuse headache is defined in chapter 8 under section 8.2. The diagnostic criteria is:
(A) Headache occurring on 15 or more days per month in a patient with a preexisting headache disorder
(B) Regular overuse for greater than 3 months of one or more drugs that can be taken for acute and/or symptomatic treatment of headache.
(C) Not better accounted for by another ICHD-3 diagnosis.
It usually, but not invariably, resolves after the overuse is stopped.
It has 8 subforms: medication overuse headache induced by ergotamine, triptans, non-opioid analgesics (including paracetamol, NSAID, and acetylsalicylic acid), opioids, combination analgesic, undefined multiple drug classes, and others. Another new section is 8.3, which defines withdrawal headache due to withdrawal from opioids, caffeine, oestrogens, and other substances.
Table 1. 8.2 Medication-overuse Headache
(A) Headache occurring 15 or more days per month in a patient with a preexisting headache disorder
(B) Regular overuse for more than 3 months of one or more drugs that can be taken for acute and/or symptomatic treatment of headache
(C) Not better accounted for by another ICHD-3 diagnosis
Table 2. Sub-entities of Medication Overuse Headache
8.2 Medication-overuse headache
8.2.1 Ergotamine-overuse headache
8.2.2 Triptan-overuse headache
8.2.3 Non-opioid analgesic-overuse headache
18.104.22.168 Paracetamol (acetaminophen)-overuse headache
22.214.171.124 Non-steroidal anti-inflammatory drug (NSAID)-overuse headache
126.96.36.199.1 Acetylsalicylic acid overuse headache
188.8.131.52 Other non-opioid analgesic overuse headache
8.2.4 Opioid-overuse headache
8.2.5 Combination analgesic-overuse headache
8.2.6 Medication-overuse headache attributed to multiple drug classes not individually overused
8.2.7 Medication-overuse headache attributed to unspecified or unverified overuse of multiple drug classes
8.2.8 Medication-overuse headache attributed to other medication
8.3 Headache attributed to substance withdrawal
8.3.1 Caffeine-withdrawal headache
8.3.2 Opioid-withdrawal headache
8.3.3 Oestrogen-withdrawal headache
8.3.4 Headache attributed to withdrawal from chronic use of other substance