The recent guideline update found that there is an insuffi-
cient data regarding the efficacy of verapamil and nimodipine
for migraine prevention, although 1 trial demonstrated
evidence that verapamil was similar to propranolol for
migraine prevention.20,23 Verapamil is usually started at a
dose of 80 mg daily and is slowly titrated to effective doses,
usually in the range of 320-640 mg daily. Another calcium
channel blocker, flunarizine has shown some promise, but is
not currently available in the United States.20 Nimodipine
and nifedipine have demonstrated mixed results, but the use
of these medications can be seen in clinical practice.13
Calcium channel blockers may be more effective for migraine
with aura rather than migraine without aura.20 Side effects of
calcium channel blockers include constipation, ankle swelling,
fatigue, and heart block.