The pharmacology of current anti-migraine drugs.

The major finding of this analysis is that acute anti-migraine agents (e.g., ergots, sumatriptan) share high affinity for 5-HT1D receptors. This receptor appears to be present in certain intracranial blood vessels. It is also found on nerve terminals where it inhibits the release of 5-HT and other neurotransmitters. Theoretically, 5-HT1D receptor agonists may acutely inhibit the release of vasoactive and/or pain-inducing substances in the perivascular space. Conceivably, drugs acting at this receptor would stop the progression of this perivascular process. In contrast, a number of prophylactic anti-migraine drugs share a relatively high affinity for 5-HT2 receptors in human brain. Although this receptor is also found in certain blood vessels, it is present throughout the nervous system. The receptor appears to mediate neuronal depolarizations at the cellular level. No hypothesis, at present, readily explains the effectiveness of prophylactic anti-migraine drugs based on this receptor. These data offer a novel approach to the analysis of anti-migraine agents. Drugs could be selected for use in clinical migraine studies based on their selectivity for a specific 5-HT receptor subtype. "Pure" drugs could be chosen which would essentially limit the number of possible sites of action for the drugs. For example, an agent which displays both high affinity and selectivity for 5-HT1D receptors could be clinically evaluated. Its effectiveness, or lack thereof, would indicate the importance of the specific 5-HT receptor site in the pathogenesis of migraine. Further attempts to determine a common mechanism of action for effective anti-migraine agents should facilitate the elucidation of the pathogenesis of this neurological syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)