Intractable migraine (status migrainosus)
Intractable migraine (status migrainosis) is defined as a migraine attack that persists for more than 72 hours. However, patients may present earlier than this because their usual drug/s for an acute attack have not been effective—other treatment (usually parenteral) may be needed to relieve the headache, and is usually provided in a hospital setting.
Rehydrate the patient and give a parenteral antiemetic if needed.
When acute migraine does not respond to first-line oral treatment and is severe, use:
1 sumatriptan 6 mg subcutaneously (only if a triptan has not been given in the last 2 hours and a parenteral triptan has not been tried) migraine, intractable (status migrainosus) sumatriptan
OR
2 ketorolac 30 mg by slow deep injection intramuscularly (only if an oral NSAID has not been given in the last 4 to 6 hours). migraine, intractable (status migrainosus)
If a parenteral triptan or NSAID is contraindicated or the migraine does not respond, and the patient is in hospital, the next step is chlorpromazine. Perform an electrocardiogram to exclude a prolonged QTc interval. Check the serum potassium and magnesium concentrations (see advice). If the patient is at risk of a high or low serum potassium concentration or a low serum magnesium concentration, wait for the blood test results before giving the first dose of chlorpromazine.
To avoid hypotension, pretreat with a fluid bolus (eg sodium chloride 0.9% 500 mL). Monitor blood pressure and fluid status every 30 minutes during treatment with chlorpromazine, and repeat the fluid bolus if needed. Use:
chlorpromazine 12.5 mg in sodium chloride 0.9% 100 mL intravenously over 30 minutes. If needed, repeat infusion twice, 30 minutes after preceding infusion ends (total chlorpromazine dose 37.5 mg). migraine, intractable (status migrainosus) chlorpromazine
Chlorpromazine can cause an acute dystonic reaction. If so, treat with:
benzatropine 1 to 2 mg intravenously, as a single dose. acute dystonia, due to chlorpromazine for intractable migraine benzatropine
Although chlorpromazine is more effective, a corticosteroid is an alternative. Use:
dexamethasone 12 to 20 mg intravenously. Repeat after 12 hours if needed. migraine, intractable (status migrainosus) dexamethasone
If the patient has not had a triptan in the preceding 24 hours, another option for treating intractable migraine is dihydroergotamine. Do not give a triptan for 24 hours after dihydroergotamine therapy.
Lidocaine is the last option, but should only be administered in a monitored inpatient setting.
While not supported by strong evidence, intravenous magnesium sulfate may be helpful, especially if the serum magnesium concentration is low (normal adult range is 0.8 to 1.0 mmol/L; see infusion advice).