Hello, You re right, it is not a vitamin tablet. Flunarizine is a calcium channel blocker and an antihistamine commonly prescribed for the prevention of migraine, occlusive peripheral vascular disease, vertigo of central and peripheral origin and other conditions. A migraine can cause severe throbbing pain or a pulsating sensation, usually on just one side of the head. It s often accompanied by nausea, vomiting, and extreme sensitivity to light and sound. His doctor seems to have prescribed this drug to prevent the migraine. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Mohammed Taher Ali