- History of at least one typical attack of migraine with or without aura every 6 weeks,
as defined by the International Headache Society (IHS) criteria.
- Capable of taking study medication as outpatients and recording its effects.
- Pregnant or breast-feeding women
- Migraine subjects who also suffered from concomitant frequent (non-migraine) headache,
defined as more than six headaches per month on average
- Migraine attacks that were thought to be atypical and had consistently failed to
respond to medical therapy.