Calcium channel blockers and stroke.

The most frequent indication for Calcium Channel Blockers (CCBs) is their use as antihypertensive agents for primary or secondary stroke prevention. Hypertension contributes to virtually all mechanisms of stroke, of atherothrombotic, lacunar, cardioembolic and intraparenchymal hemorrhage types. In comparison with the rather univocal mechanisms underlying coronary artery or peripheral artery disease, the variable mechanisms of stroke are the main reason explaining not only the different impact of vascular risk factors, but also the different effects of drugs given for prevention. In an acute stroke setting, lowering blood pressure is potentially harmful, especially if it is carried out using short-acting dihydropyridine derivatives. Some CCBs, such as nicardipine, are preferred in certain conditions (including acute thrombolysis). In stroke, CCBs may also play a role as neuroprotectants. Then twofold effect--against vessel wall changes and as neuroprotectants (after ischemia or degenerative insults)--make this class of drugs of interest for their possible application in the setting of dementias, particularly that of vascular dementia. Some CCBs have been tested and are of benefit when used for preventing or treating cerebral vasospasm after subarachnoid hemorrhage. CCBs must be considered effective in preventing stroke in hypertensive patients. In comparison with other antihypertensive agents, their effects are similar to or even better than those exerted by other drugs. This may be due to the fact that stroke includes different types, with differing underlying pathophysiological mechanisms. The anti-atherosclerotic properties of CCBs may be useful in preventing the atherothrombotic type of stroke at the large pre-cerebral artery level. Dihydropyridinic derivatives may play a selective role in relation to small-vessel disease of the brain, which leads to multiple stroke-associated conditions, including lacunar infarct, intra-cerebral hemorrhage and subcortical vascular dementia. Oral nimodipine is recommended in the prevention/treatment of cerebral vasospasm following subarachnoid hemorrhage (SAH). CCBs, particularly nimodipine, may be of some benefit in vascular or mixed degenerative and vascular dementia or, taking into account subtypes, more selectively in subcortical vascular dementia. In this setting, CCBs may contribute toward reducing the risk of recurrent stroke in patients who are usually at high risk of recurrence.