Sumigran Mechanism of Action

Pharmacology: Pharmacodynamics: Mechanism of action: Sumatriptan is a selective agonist of vascular serotonin (5-hydroxytryptamine; 5-HT) type 1B and 1D receptors on intracranial blood vessels and sensory nerves of the trigeminal system; causes vasoconstriction and reduces neurogenic inflammation associated with antidromic neuronal transmission correlating with relief of migraine.
Pharmacokinetics: Sumatriptan is rapidly absorbed following oral administration; oral absorption appears to occur in the small intestine. The bioavailability of sumatriptan following oral administration averages only about 15%, principally because of presystemic metabolism of the drug and in part because of incomplete absorption. Sumatriptan is approximately 14-21% bound to plasma proteins over a concentration range of 10-1000 ng/mL. Sumatriptan is distributed into milk in humans and animals. The elimination half-life is 1.5-2.6 hours. Sumatriptan is metabolized in the liver and possibly in the GI tract and is eliminated in urine and feces. Sumatriptan is excreted in urine via glomerular filtration and tubular secretion, but renal plasma clearance accounts for only 22% of the systemic clearance of 1176-1200 mL/min.