migraine
"I'm 59 years old, and have experienced migraines since age 5.  Imitrex is the best drug I've used.  I take 100 mg at the first sign, and it prevents it 80% of the time.  If taken after the headache starts, it stops the pain within 1 hour, and much faster if I lay down.  Yes, there are mild side effects--drowsiness, sensitivite to hot and cold, but it sure is better than a headache."