Sumatriptan succinate (GR 43175), a serotonin1 (5-HT1) receptor agonist, is used in the acute treatment of a migraine headache.

5-HT1A receptor:100 nM (Ki), 5-HT1B receptor:27 nM (Ki), 5-HT1D receptor:17 nM (Ki)

Sumatriptan is rapidly cleared through metabolism and renal elimination, with a half-life of 1-2 hours. It rarely produces adverse effects when administered acutely, except for dogs exhibiting low tolerance to high doses. Clinically, subcutaneous injection of Sumatriptan at 100 mg/kg notably decreases injury-induced and contralateral mechanical allodynia in a rat model of trigeminal neuropathic pain (peak effects at 6.3g and 4.4g, respectively). In cats, Sumatriptan reduces the number of Fos-positive cells in the caudal part of the spinal trigeminal nucleus (I, IIO, and C2) following mechanical stimulation (to 6, 13, and 9 cells, respectively). The compound's biological activity varies across species, with 37%, 23%, and 58% in rats, rabbits, and dogs, respectively. Sumatriptan selectively constricts cranial blood vessels, which are dilated and inflamed during migraines, mediated by the 5-HT1 receptor subtype in animal cranial vasculature.

Sumatriptan significantly reduces plasma protein-induced extravasation triggered by electrical stimulation of the trigeminal nerve. It mitigates morphological changes in the capillaries within the dura mater and small veins in the presence of hypertrophied mast cells stimulated at the trigeminal ganglion. Sumatriptan has a slightly lower affinity for the serotonin receptor 1A binding site (KI=100 nM), while exhibiting the highest affinity for 5HT (Ki=17 nM) and 5HT1B receptor binding sites (Ki=27 nM).