Imitrex and migraines compared to headaches

[Amie-Arbaugh]

  The first time I was given an Imitrex injection was by a doctor.  He told me that if it elivates my symptoms then he knew I had a migraine,he said that Imitrex only works on migraines and not other kinds of headaches.  What is the physiological difference between a migraine headache and other forms of headaches?  Why wouldnt medications such as Imitrex not work on regular headaches.  I would think that if it worked on a migrane it would work on another kind of headache.

[CCF Neuro[P] MD RPS]

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Dear Ms. Arbaugh:
Sorry to hear about your headaches.  Your doctor is sort-of correct.  Most, but not all migraine headaches will respond in some fashion to imitrex.  The pathophysiology for migraine is very suggestive of a depletion of serotonin at a specific receptor subtype.  Imitrex is a serotonin agonist and binds to the serotonin receptor and thus reduced the migraine headache.  However, some migraines are due to depletion of a specific calcium channel and therefore, on this subtype of migraine headache imitrex would have little or no effect.  Another type of migraine is thought to be mitochondrial in origin and thus neither calcium channel blockers or imitrex would be effective, and riboflavin would be the medication of choice.  Other types of headache are not related to the serotonin depletion, calcium channel defect, or mitochondrial disorder.  For instance, cluster headache is thought to be related to a posterior hypothalmus defect.  So, as you can see, there are distinct etiologies for headache and most of the types of headaches have multiple etiologies and therefore respond to medications in a distinct manner.  I hope that this helps you.  I also hope you headaches get better.
Sincerely,
CCF Neuro[P] MD