REVIEW OF CARDIOVASCULAR EFFECTS OF FLUOXETINE, A SELECTIVE SEROTONINE REUPTAKE INHIBITOR, COMPARED TO TRICYCLIC ANTIDEPRESSANTS

Fluoxetine is an antidepressant drug, a potent and specific inhibitor of serotonin reuptake (SSRI). Evidence suggests that being compared wi th tricyclic antidepressants, fluoxetine may cause significantly fewer anticholinergic, antihistaminergic and cardiotoxic side effects in th e treatment of major depressive disorders. Chronic treatment with fluo xetine was not reported to affect the electrocardiogram (ECG). There i s no clinical evidence of conduction delay and very little evidence of orthostatic hypotension. In the overdosed patients fewer cardiac symp toms were reported than with tricyclic antidepressants. However, dysrh ythmia (atrial fibrillation and bradycardia) and syncope associated wi th fluoxetine treatment and overdose were reported. Although such repo rts have not been common, they do raise concerns. Thus we investigated the direct cardiovascular effects of the fluoxetine in isolated heart preparations and vessels of rats and rabbits. From 10(-6)M to 10(-4)M concentrations fluoxetine showed cardiodepressant and vasodilatory ef fects. These effects were similar to those of previously reported on t ricyclic compounds. This review is a brief summary of possible cardiov ascular effects of fluoxetine and other new SSRls antidepressants from the literature based on experience of clinical studies and our experi ments with fluoxetine on isolated rat and rabbit cardiac preparations and vessels. Possible explanations of the lower incidence of cardiovas cular complications with fluoxetine in humans and cardiodepressant eff ects in vitro are discussed.