Dexamethasone is a safe and cheap abortive therapy for migraine headache. The effect of it is never evaluate and not correlate with the effect of popular anti migraine medication such as dihydroergotamine. The investigators proposal is to compare its effect with dihydroergotamine.

Inclusion Criteria:

1. Migraine attack according to international headache society criteria

2. Migraine without aura; at least 5 attack with mean duration of 4 to 72 hours and 2 of following:

   • Unilateral

   • Pulsatile

   • Severe enough to impair daily activity

   • Aggravate with walking and climbing, also 1 of following:

     • Nausea and or vomiting
     • Photophobia and phonophobia, and not contributed to other headache.

3. Migraine with aura; at least 2 attacks with 3 of following:

   • One reversible aura
   • Aura became apparent at least in 4 minutes
   • Aura not lasting more than 60 minutes
   • Headache develops in less than 60 minutes after aura

Exclusion Criteria:

1. Hypertension

2. Ischemic heart disease

3. Basilar migraine with sign and symptoms such as:

   • Diplopia
   • Ataxia
   • Dysarthria
   • Dysphagia
   • Weakness
   • Sensory disorder
   • Drowsiness

4. Peripheral vascular disease

5. Sepsis

6. Age more than 40 and less than 15 year old

7. Pregnancy

8. Use of triptans and ergots derivatives in past 24 hours