A Role for Catecholamines in the Pathogenesis of Neuroleptic Malignant Syndrome

The authors present a case report in which an agitated response to antidepressants preceded the neuroleptic malignant syndrome (NMS). In a review of 64 cases of NMS in the literature, they found that 80% were described as agitated prior to the development of the syndrome. Polypharmacy was common. A review of the literature on theories of pathogenesis involving sympathetic amines other than dopamine is presented to explain this phenomena. It is suggested that these toxic reactions to medication can be interpreted as resulting from a relative NE/DA excess, in which antidepressants increase the numerator, while neuroleptics functionally decrease the denominator. It is recommended that where an agitated response to antidepressants is observed, neuroleptics should be used only with considerable caution.