Introduction Acute migraine commonly causes significant personal, economic and work-related disability. Australian guidelines recommend treating mild migraine with aspirin and metoclopramide, and moderate-severe migraine with prochlorperazine, chlorpromazine or sumatriptan. Stratified treatment based on severity is preferred to step-wise treatment. Australian data regarding Emergency Department (ED) migraine treatment are scarce. We evaluated prescribing patterns at a Melbourne hospital against national guidelines.

Methods Retrospective cohort study of migraine (G439 ICD-10-AM) between 2012–2016. Exclusion criteria included migraine without headache, other primary headaches and secondary headaches. Demographic and prescribing data were extracted from medical records. Proportions were calculated with 95% confidence intervals using Wilson’s method. Comparisons were made between groups using Mann-Whitney and Chi-square tests.

Results Of 214,932 ED presentations, 744 with headache presentation received a G439 diagnosis. Most were female (75%; 558/744), young (mean age 34±13 years) and self-reported migraine history (75%; 558/744). There were 55 different medications prescribed. Paracetamol was more frequently prescribed (52%; 385/744) than aspirin (10.6%; 78/744). Opioid prescription occurred in 46% (345/744), single opioid 36% (267/744),>1 opioid 10% (78/744). Median time-to-discharge was 38 min longer with opioid prescription compared with no opioid (222; IQR 164–309 vs 184; 122–258; p<0.01). Just 6.85% (51/744) received triptans. Other treatments were prochlorperazine (14%; 97/744), metoclopramide (38%; 286/744) and chlorpromazine (44%; 3 25/744). Overall, 25.4% (189/744) received no guideline-recommended medication.

Conclusion We observed considerable polypharmacy in ED migraine management with inconsistent prescribing patterns. Recommended medications are infrequently used. Opioid use is common and associated with increased time-to-discharge. Failure of ED staff to follow guidelines is unexplained, and requires further investigation.