[Calcium channel blockers and prevention of migraine]

Calcium antagonists have been proposed for the prophylactic treatment of migraine because of their putative vasodilating antispasmodic effect and of their action against the cellular consequences of brain hypoxia. Published reports of controlled double-blind studies of calcium antagonists for the prophylactic treatment of migraine are reviewed herein. The effectiveness of verapamil, diltiazem, and nifedipine in this indication cannot be considered as firmly demonstrated, when problems with trial design and the amount of available data are taken into account. Nimodipine failed to demonstrate significant effectiveness in migraine with or without an aura. In contrast, the ability of a diphenylpiperazine, flunarizine, to decrease the incidence of migraine attacks in patients with common or classical migraine has been firmly demonstrated, although there is less evidence of this agent's effectiveness on the duration and severity of attacks. The percentage of patients who respond to flunarizine seems comparable to the percentages of propranolol or pizotifen responders. However, flunarizine is associated with unpleasant (weight gain) or severe (extrapyramidal or depressive symptoms) adverse effects which limit its place to that of a second-line drug. Lastly, the analysis of these studies failed to disclose a correlation between calcium movements across the cell membrane and effectiveness for the prevention of migraine attacks. Flunarizine's effect in migraine probably involves monoamine mechanisms which bear no relation to calcium.