7. Medication overuse guidance

Background

Medication overuse headache (MOH) is defined as headache occurring on 15 or more days per month in a patient with a pre-existing primary headache and developing as a consequence of regular overuse of acute or symptomatic medication for 3 months. Not all patients taking frequent acute medication for the management of primary headache have MOH. MOH can develop in patients taking medication for other painful conditions.

MOH most commonly occurs as a complication of the management of migraine, although it can occur in any primary headache disorder. It rarely occurs in cluster headache and if it does the patient usually also has migraine.

Any acute or symptomatic medication taken for the management of primary headache can result in MOH, although the highest risk is with triptans and opioids.

Simple analgesics (Aspirin, NSAIDs, Paracetamol) > 15 days per month
Triptans, opioids and combination analgesics > 10 days per month

Medication overuse headache: Prevention

When prescribing acute treatment in primary headache patients should be warned about the risk of medication overuse headache. This is particularly important in patients with migraine. In general the use of simple analgesics and triptans should be restricted to 8-10 days per month. The use of combination analgesics and opioids should be avoided. Preventative treatment should be considered early in patients with frequent headache.

In cluster headache, because the headaches are so severe and the risk of MOH very low, patients should be allowed to use up to 2 doses of a triptan per day (subcutaneous sumatriptan or nasal sumatriptan/ zolmatriptan).

Medication overuse headache: Investigation

Before diagnosing MOH it is important to consider other secondary causes of chronic daily headache and investigate appropriately.

Medication overuse headache: Treatment strategies

Explanation

Adequate explanation is the key to managing MOH. The patient should be made aware that frequent use of acute medication “winds up” the migraine process making it more likely to happen and results in chronic headache. MOH is a recognised complication of the management of headache and rationalising/stopping medication can improve headache. Patients should be aware that headache can worsen before it improves (re-bound headache) and that this can last for days/weeks. Headache may still require appropriate management with acute and preventative treatment following medication withdrawal. Resuming frequent acute medication use is likely to result in re-emergence of MOH.

Medication withdrawal

Medication withdrawal is the recommended strategy in patients with MOH. For simple analgesics and triptans abrupt withdrawal is preferable. For combination analgesics (particularly those containing high dose codeine) and opioids gradual withdrawal is recommended. The patient should be warned to expect withdrawal headaches. Other symptoms commonly encountered include: nausea, sleep disturbance and anxiety. Anti-emetics should be considered during the withdrawal phase and patients advised to keep adequately hydrated. Patients overusing triptans can be expected to improve over 7-10 days and those overusing simple analgesics over 2-3 weeks, but improvement can take a few months. For those who cannot manage abrupt withdrawal rationalising acute medication to 2 days per week can be helpful.

Because medication withdrawal usually results in improvement rather than cessation of headaches adding in or adjusting preventative medication at the same time as initiating withdrawal should be considered.

Preventative treatment

The effectiveness of most oral preventative treatments is reduced in MOH and if a preventative treatment is started this should be combined with rationalisation of the overused medication. Topiramate, Botulinum Toxin A and CGRP monoclonal antibodies are less likely to be affected by medication overuse.

Referral criteria to secondary care (medication overuse headache)

In patients with Medication Overuse Headache an adequate explanation, trial of medication withdrawal and consideration of starting prophylactic treatment should be undertaken prior to referral into secondary care.

References and further resources

Wakerly, B. Medication Overuse Headache. Practical Neurology. 2019;19:399-403
SIGN 155 Pharmacological management of migraine – updated March 2023; includes clinician and patient guidelines Pharmacological management of migraine (sign.ac.uk)
British Association for the Study of Headache (BASH) National Management System 2019; includes clinician and patient portals Headache UK

gjnh.cfsdpmo@gjnh.scot.nhs.uk