Question: What are the mechanisms of action of triptan drugs used in the treatment of migraine headaches?
Answer: The listed reference states “Triptans are serotonin agonists with high affinity for 5-HT1B and 5-HT1D receptors. Triptans were originally thought to provide relief from migraine by causing cranial vasoconstriction, most likely through action at postsynaptic 5-HT1B receptors on smooth muscle cells of blood vessels. It is now theorized that triptan also block the release of vasoactive peptide from the perivascular trigeminal neurons through their action at presynaptic 5-HT1D receptors on nerve terminals. In addition, triptans bind to presynaptic 5-HT1D receptors in the dorsal horn, and this binding is thought to block the release of neurotransmitters that activate second order neurons ascending to the thalamus. Triptans may also facilitate descending pain inhibitory systems.” (Loder E. Triptan therapy in migraine. 2010 NEJM 363:63-70)