Medication overuse headache
Medication overuse can cause a rebound headache as the dose wears off, and limit the efficacy of migraine prophylaxis. It can also cause a secondary headache disorder that is superimposed on the primary headache. Patients with migraine and tension-type headache are more susceptible to medication overuse headache than patients with cluster headache. Opioid analgesics (including codeine), triptans and ergots (ie ergotamine, dihydroergotamine) are more potent than nonopioid analgesics in inducing medication overuse headache. Patients taking opioid analgesics, triptans or ergots for more than 10 days per month are at risk. Nonopioid analgesics (eg paracetamol, NSAIDs) can induce medication overuse headache when taken for more than 15 days per month.
Appropriate management includes counselling the patient on the risks associated with taking analgesics too often. If headaches need treatment more than 4 days per month, consider starting a preventive drug. If the patient's use of headache drugs is escalating, re-evaluate the diagnosis and then consider a preventive drug. The patient may need expert referral to manage psychological problems that contribute to medication overuse, to overcome fear of analgesic withdrawal, and to manage psychiatric comorbidities (eg anxiety). Start a preventive drug before withdrawing analgesic medication from patients with medication overuse headache—if they are already on a preventive drug, review therapy and change if needed.
Strategies for analgesic medication withdrawal include:
- a graded reduction in dose and frequency
- bridging therapy.
An NSAID or a short course of prednisolone (or prednisone) can be used as bridging therapy while withdrawing an opioid analgesic or triptan. Use:
1 naproxen modified-release 750 mg orally, once daily for 5 days in the first week, then 3 to 4 days per week for 2 weeks, then stop headache, medication overuse naproxen
OR
2 prednisolone (or prednisone) 50 mg orally, once daily for 3 days. Decrease dose gradually over 7 to 10 days, then stop. headache, medication overuse prednis ol one
After bridging therapy, restart the patient's usual acute medication with restrictions on frequency (less than 10 days a month for triptans or opioid analgesics, less than 15 days a month for nonopioid analgesics). If it is unlikely that the patient will restrict use of a triptan, prescribe an NSAID instead.
In severe refractory cases, refer for expert management in hospital. Possible therapy includes lidocaine or ketamine infusion.