Medication Overuse Headache

Medication overuse headache is a secondary headache that develops or worsens in a person with a pre-existing primary headache disorder (usually migraine or tension type headache) who takes acute headache medicines too often for more than 3 months, so that the treatment itself maintains a daily or near daily headache.

• Defining pattern: headache on 15 or more days a month, with regular overuse for over 3 months of simple analgesics (paracetamol, aspirin, NSAIDs) on 15 or more days a month, or of triptans, ergotamine, opioids, codeine containing or other combination analgesics on 10 or more days a month.
• Opioids (especially codeine) and combination analgesics cause overuse at the lowest frequency; simple analgesics need the highest.
• Prevalence is about 1 to 2 percent of adults, with a female predominance of about 3 to 4 to 1; it is the commonest cause of chronic daily headache seen in primary care after chronic migraine.
• Risk factors: frequent migraine, anxiety and depression, other chronic pain, obesity, high caffeine intake, sedative use, and unsupervised self-medication.
• Mechanism involves central sensitisation and down regulation of the endogenous pain modulating systems, which is why prevention fails while overuse continues.

• Daily or near daily headache, often present on waking, that improves briefly after each dose then recurs as the dose wears off, with progressively shorter relief.
• Headache character changes over time: migraine features blend with tension type features, and triggers become less obvious.
• Patient reports needing to take medicines "just in case" and fear of headache if medicines are withheld.
• Associated fatigue, irritability, poor concentration, nausea, restlessness and sleep disturbance.
• Medication history is essential: ask about every product, including over-the-counter combinations containing caffeine or codeine, and count days of use per month using a diary.
• Examination is normal; look for neck stiffness, papilloedema, focal deficit and temporal artery tenderness to exclude other causes.

• Clinical diagnosis from a 4 week headache and medication diary showing headache on 15 or more days a month with simple analgesics taken on 15 or more days a month, or triptans, ergotamine, opioids or combination analgesics taken on 10 or more days a month, for over 3 months.
• Exclude secondary headache with red flags: new headache after age 50, thunderclap onset, progressive course, papilloedema, systemic illness, immunosuppression, cancer history, pregnancy, positional or exertional pattern.
• Investigations are for complications and alternatives: FBC, ESR or CRP (giant cell arteritis if over 50), renal and liver function (to direct analgesic and preventive choice, and to detect analgesic nephropathy or hepatotoxicity), and neuroimaging only when red flags exist.
• Screen for depression and anxiety (PHQ-9, GAD-7), sleep disorder and excess caffeine.
• Differentials: chronic migraine without overuse, chronic tension type headache, new daily persistent headache, hemicrania continua, idiopathic intracranial hypertension, giant cell arteritis, sinus disease, cervicogenic headache.

Education and plan

• Explain that the headache is driven by the medicine, that it improves after withdrawal in most patients, and that headache usually worsens for 2 to 10 days before it improves. Agree a date to stop.
• Give written advice and a headache diary; review at 2 weeks and 4 to 6 weeks.
• Limit all acute treatment afterwards to no more than 2 days a week for simple analgesics and triptans.

Withdrawal

• Simple analgesics, NSAIDs, triptans and ergotamine: stop abruptly.
• Opioids, codeine combinations, barbiturates and benzodiazepines: reduce gradually over 2 to 4 weeks (for codeine, reduce the daily dose by about 25 percent each week) because of withdrawal symptoms (anxiety, sweating, diarrhoea, insomnia); supervise carefully.
• Reduce caffeine to under 200 mg a day (about 2 cups of coffee).
• Antiemetic for withdrawal nausea: metoclopramide 10 mg orally up to 8 hourly for no more than 5 days, or domperidone 10 mg orally up to 8 hourly for no more than 7 days.

Bridging therapy (optional, for severe withdrawal headache)

• Naproxen 500 mg orally twice daily with food and omeprazole 20 mg daily for 2 to 4 weeks (not in those who had been overusing NSAIDs, or with renal impairment, ulcer or cardiovascular disease), or
• Prednisolone 60 mg orally once each morning for 5 days then 40 mg for 5 days then 20 mg for 5 days, then stop (check blood pressure and glucose; avoid in uncontrolled diabetes and hypertension and in pregnancy).

Preventive treatment (start at the time of withdrawal, not after)

• Topiramate 25 mg orally at night, increase by 25 mg each week to 50 mg twice daily (maximum 100 mg twice daily). Side effects: paraesthesia, cognitive slowing, weight loss, kidney stones; contraindicated in pregnancy and in women of childbearing potential without effective contraception (it also reduces the effectiveness of oestrogen containing contraceptives at doses over 200 mg daily). Monitor bicarbonate.
• Amitriptyline 10 mg orally at night, increase by 10 mg weekly to 50 to 75 mg (maximum 100 mg). Avoid in arrhythmia, recent myocardial infarction, glaucoma, urinary retention.
• Propranolol modified release 80 mg orally once daily, increase to 160 mg (maximum 240 mg). Avoid in asthma, heart block, bradycardia.
• Candesartan 8 mg orally once daily, increase to 16 mg after 2 weeks (check urea, electrolytes and creatinine at 2 weeks; avoid in pregnancy).
• Onabotulinumtoxin A 155 units intramuscularly across 31 sites every 12 weeks, for chronic migraine with overuse, given by a trained clinician.
• Anti-CGRP antibodies (specialist initiated): erenumab 70 mg subcutaneously monthly (increase to 140 mg), fremanezumab 225 mg monthly or 675 mg every 3 months, galcanezumab 240 mg loading then 120 mg monthly.
• Allow 8 to 12 weeks at target dose before judging benefit. Add cognitive behavioural therapy, regular sleep, regular meals, hydration and graded exercise.

Follow up and outcome

• About 50 to 70 percent improve within 2 months of withdrawal; relapse in the first year is about 30 to 40 percent, highest with opioid overuse.
• Refer to a headache clinic for failed withdrawal, opioid dependence, or diagnostic uncertainty.

Special groups

• Pregnancy: use paracetamol 1 g (maximum 4 g daily) and metoclopramide for acute attacks; avoid topiramate, valproate, candesartan and NSAIDs after 20 weeks; propranolol or amitriptyline are the usual preventives.
• Children and adolescents: withdraw analgesics with parental supervision; use amitriptyline 10 mg at night or propranolol 10 to 20 mg twice daily; topiramate 25 mg at night increasing slowly under specialist care.