A POTENT SELECTIVE 5-HT 1D RECEPTOR AGONIST. IT PRODUCE A DOSE-RELATED VASOCONSTRICTION IN THE CEREBRAL CIRCULATION. IT DOES NOT BIND TO ALPHA ADRENERGIC, BETA ADRENERGIC, MUSCARINIC, DOPAMINERGIC OR BENZODIAZEPINE RECEPTOR. IT PROVIDES RELIEF IN BOTH THE HEADACHE AND OTHER SYMPTOMS SUCH AS NAUSEA AND PHOTOPHOBIA.