Neurologic complications of FK 506.

Abstract

FK 506 is used increasingly to prevent rejection in organ transplantation. Both experimental1-3 and clinical4,5 studies suggest that FK 506 is a more potent immunosuppressive agent than cyclosporine (CyA), and there are indications that FK 506 may also be less toxic.6 The advent of any new agent such as FK 506 promises more effective immunosuppression, but also gives rise to the need for further study of potential toxic side effects. Indeed, a report by Reyes et al7 of two patients who developed speech dysfunction while on FK 506 suggests that this agent may under certain circumstances produce adverse effects on the nervous system. Thus, more information is needed about potential nervous system disturbances that may occur in association with the clinical use of FK 506 in transplant patients. We carried out this study to identify the spectrum and frequency of neurologic disturbances that may occur in transplant patients receiving FK 506.