<p>Almotriptan is a selective and potent serotonin (5-hydroxytryptamine 1B/1D) agonist. Almotriptan binds to specific serotonin receptors on meningeal arteries inhibiting the release of vasoactive peptides and causing constriction of the arteries. It has a limited effect on arteries supplying blood to the brain and little effect on cardiac and pulmonary vessels.</p>