Cardiovascular adverse effects of antipsychotic drugs

Minor cardiovascular adverse effects from antipsychotic drugs are extremely common. They include effects such as postural hypotension and tachycardia due to anticholinergic or alpha(1)-adrenoceptor blockade, and may occur in the majority of patients at therapeutic dosages. There are a number of phar macological effects that are of uncertain clinical significance, such as bl ockade of calmodulin, sodium and calcium channels and alpha(2)-adrenoceptor s in the central nervous system. The most serious consequences of treatment , arrhythmias and sudden death, are probably uncommon and are most likely t o be caused primarily by blockade of cardiac potassium channels such as HER G. Incomplete evidence suggests that arrhythmias and sudden death are a par ticular problem with certain drugs (thioridazine and droperidol), high risk populations (elderly, pre-existing cardiovascular disease, inherited disor ders of cardiac ion channels or of antipsychotic drug metabolism) or people taking interacting drugs (such as drugs that prolong the QT interval, e.g. bicyclic antidepressants, drugs that inhibit antipsychotic drug metabolism , or diuretics). Clozapine may be unique in also causing death from myocard itis and cardiomyopathy. Much further research is required to more clearly identify high risk drugs and the populations that are at risk of sudden dea th, as well as the mechanisms involved and the extent of the risk.