Activation of these receptors located on intracranial blood vessels, including those on arteriovenous anastomoses, leads to vasoconstriction and thus relief of migraine. Another possibility is that activation of these receptors on sensory nerve endings in trigeminal system causes inhibition of pro-inflammatory neuropeptide release. Well absorbed from GI tract. Unchanged drug and metabolites are primarily eliminated in urine.
Excretion is decreased in moderate liver or renal impairment.
Use for prophylaxis of migraine or for management of hemiplegic or basilar migraine. Use with caution during lactation and with diseases that may alter the absorption, metabolism, or excretion of drugs, such as impaired renal or hepatic function. Most common side effects follow. Paresthesia, dizziness, drowsiness, malaise, fatigue. Vertigo, tremors, cognitive function disorders, sleep disorders, disorders of equilibrium, anxiety, depression, detachment.