Decision support only — not a substitute for eTG, headache-society guidance, or your neurology team. Two arms that interact: treat attacks early, but cap acute-medication frequency — because acute overuse is itself what tips episodic migraine into chronic. Exclude secondary headache before settling on migraine. Verify all doses and PBS criteria.
1 Acute treatment — stratify by severity, treat early
Mild–moderatefirst reach
Tolerable, not yet disabling.
NSAID (aspirin 900 mg, naproxen, ibuprofen) or paracetamol + antiemetic (metoclopramide/prochlorperazine). Take at onset — late dosing fails.
Moderate–severeor NSAID failed
Disabling attacks, or simple analgesia ineffective.
Triptan (e.g. sumatriptan 50–100 mg) ± NSAID/antiemetic; the triptan + NSAID combination beats either alone. SC or nasal if vomiting or fast onset needed. One triptan failing ≠ all — switch agent before abandoning the class.
Triptan unsuitableCV disease / non-response
Ischaemic heart/cerebrovascular disease, uncontrolled HTN, or triptan failure.
Gepant (ubrogepant, rimegepant; zavegepant nasal) or ditan (lasmiditan) — no vasoconstriction. Lasmiditan: sedation, don't drive 8h.
Refractory / statusrescue
Prolonged (>72h) or unresponsive attack.
Parenteral antiemetic, IV fluids, NSAID; dihydroergotamine (IV or intranasal) for status/triptan failure; consider greater occipital nerve block. Avoid opioids & butalbital.
The acute ceiling (to prevent medication-overuse headache): triptans / ergots / opioids / combination analgesics on ≤10 days/month; simple analgesics (NSAID/paracetamol) on ≤15 days/month. Crossing these reliably converts episodic to chronic migraine — see §3.
2 Prevention — when to start, and with what
Offer prevention for frequency or disability — not only once someone is "chronic."
When to offerthe threshold
≥4 migraine days/month with disability, attacks poorly controlled by acute treatment, acute-overuse risk, or patient preference.
Discuss early — prevention reduces frequency, disability, and acute-medication load.
Oral first-linechoose by comorbidity
Episodic or chronic migraine.
Propranolol/metoprolol, amitriptyline, candesartan, or topiramate. Start low, titrate, and trial 8–12 weeks at an adequate dose before judging.
Chronic migraine≥15 headache days/mo
Chronic migraine, often with overuse.
OnabotulinumtoxinA (PREEMPT protocol) PREEMPT — for chronic migraine specifically.
CGRP-targetedthe newer class
Refractory to / intolerant of oral preventives.
CGRP mAb (erenumab, fremanezumab, galcanezumab, eptinezumab) or gepant (atogepant, rimegepant). First-line in the US (AHS 2024); PBS-restricted in Australia (typically after ≥3 oral failures).
Set expectations: a ~50% reduction in migraine days is a successful preventive, not zero attacks. Don't abandon an agent before an adequate dose and duration. Re-review and consider weaning after ~6–12 months of good control.
3 Medication-overuse headache — the bridge to chronic
Recognise & reverse it
- WhoPresent in >50% of chronic migraine. Suspect it in anyone with daily/near-daily headache on frequent acute meds.
- LimitsTriptans/opioids/combination ≤10 d/mo; simple analgesics ≤15 d/mo.
- ManageWithdraw the overused drug and start prevention together. CGRP agents can work even without formal withdrawal.
- AvoidOpioids and butalbital — worst offenders for overuse, dependence, and poor efficacy.
Define it properly
- Chronic≥15 headache days/month for >3 months, with ≥8 migraine days/month (ICHD-3).
- EpisodicFewer than 15 headache days/month.
- DiaryA headache diary is the single most useful tool — quantifies frequency, acute-med days, and response.
4 Match the preventive — and the non-drug basics
Choose by comorbidity
- HTNBeta-blocker or candesartan.
- Depression/insomniaAmitriptyline.
- ObesityTopiramate (weight loss) — but cognitive effects, renal stones.
- PregnancyAvoid topiramate & valproate (teratogenic). Beta-blocker/amitriptyline are usual choices — verify.
Lifestyle & triggers
- RoutineRegular sleep, meals, hydration; consistent (not excessive) caffeine.
- ActivityRegular aerobic exercise reduces frequency.
- TriggersIdentify via diary — but don't chase elimination diets; stress and irregular routine matter more than specific foods.
Beyond drugs
- DevicesNon-invasive neuromodulation (Nerivio/REN, gammaCore/nVNS, Cefaly/e-TNS) — acute and/or preventive; useful in pregnancy or when drugs are contraindicated.
- SupplementsMagnesium, riboflavin 400 mg, coenzyme Q10 — modest evidence, cheap, pregnancy-friendly.
- MenstrualPredictable perimenstrual attacks → short mini-prophylaxis (e.g. frovatriptan or naproxen) around menses.
5 Red flags & the safety traps
Don't call it migraine if…
- Image/referThunderclap onset, new headache >50 y, progressive/positional, fever/immunocompromised, focal deficit, papilloedema, or in pregnancy/postpartum.
- PatternA clear change from the usual pattern, or "first or worst" headache.
Two safety musts
- Aura + COCPMigraine with aura + combined oral contraceptive raises ischaemic-stroke risk — avoid oestrogen; use progestogen-only/non-hormonal.
- Triptan + CVTriptans contraindicated in ischaemic heart/cerebrovascular disease — use a gepant/ditan instead.
Sources.
ICHD-3 (International Classification of Headache Disorders, 3rd ed — migraine & chronic migraine definitions, MOH). American Headache Society 2024 position statement (CGRP inhibitors as a first-line preventive option). eTG (Therapeutic Guidelines — migraine, acute & preventive) for Australian practice; PBS for triptan/CGRP/onabotulinumtoxinA criteria.
Key evidence: PREEMPT (onabotulinumtoxinA in chronic migraine); STRIVE/ARISE and the erenumab-vs-topiramate trial (CGRP mAb prevention); triptan + NSAID combination trials; gepant & ditan acute-treatment trials (ubrogepant, rimegepant, lasmiditan).
Caveats: CGRP-targeted agents and onabotulinumtoxinA are PBS authority-restricted in Australia (chronic migraine or frequent episodic after multiple oral failures, usually specialist-initiated) — confirm current criteria. Preventive choice is individualised to comorbidity and childbearing potential. Always reconsider secondary headache. Verify all doses.