Methods	Multicentre, R, DB, PC and AC, four-way cross-over Four consecutive attacks treated with single doses of each test medication
Participants	“Simple” migraine (criteria of Soyka). Aged 18-70 years (included one patient aged 75 years). Prior attacks uniform with regard to headache intensity and duration N = 288 (completed 4 attacks M 55, F 233 Mean age 42 years
Interventions	Paracetamol 1000 mg Dihydroergotamine 2 mg Paracetamol + dihydroergotamine 1000/2 mg Placebo
Outcomes	Pain-free at 2 h Headache relief at 1 h and 2 h ≤ 50% pain relief at 1 h and 2 h Presence of nausea, vomiting, photophobia, phonophobia Use of rescue medication Adverse events Withdrawals
Notes	Oxford Quality Score: R1, DB1, W1. Total = 3
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	“randomised order in the form of a Latin square”
Allocation concealment?	Unclear	Not described
Blinding? All outcomes	Unclear	Not described