Nimodipine (brand - Nimotop®) is a calcium channel blocker which may be helpful in reducing both cluster and migraine headaches. Research studies in Europe have been encouraging. In the United States, the FDA has approved this drug for treating post aneurysm hemorrhage (bleeding). It is very expensive and for this reason is used infrequently. It may be helpful to headache patients resistant to other treatment.
Side effects can include stomach and bowel complaints, irritability, light-headedness, fatigue and menstrual discomfort. Your physician should monitor you while you are taking this medication.