Description

Sumatriptan is a selective serotonin (5-HT) receptor agonist of the 5-HT${1B}$ and 5-HT${1D}$ subtypes. It is the first in a class of drugs called triptans. It is a vasoconstrictive agent that is effective in the acute treatment of migraine attacks.

Indication

Sumatriptan is indicated for the acute treatment of migraine attacks, with or without aura, in adults. It is not intended for the prophylactic (preventive) treatment of migraines. It can also be used for the acute treatment of cluster headache episodes.

Mechanism of Action

Sumatriptan’s therapeutic effect is believed to be due to its agonist action on 5-HT$_{1B/1D}$ receptors. This action leads to two main effects:

1. Cranial Vasoconstriction: It causes vasoconstriction of the intracranial blood vessels, which are thought to be dilated during a migraine attack.
2. Inhibition of Neuropeptide Release: It inhibits the release of pro-inflammatory neuropeptides, such as substance P and calcitonin gene-related peptide (CGRP), from trigeminal nerve endings. These neuropeptides contribute to the pain and inflammation associated with a migraine attack.

The combination of these two actions helps to relieve the headache and other symptoms of a migraine.