BACKGROUND: Interruption of efferent sympathetic fibers is the mainstay of therapy in reflex sympathetic dystrophies(RSD) and be accomplished by temporary or permanent anesthetic blockade of sympathetic ganglia, surgical lesions of the sympathetic trunk, intravenous injecton of guanethidine or reserpine, or by systemic administration of adrenergic blocking drugs. In this study, the effects and the side effects of intravenous regional bretylium for the treatment of RSD were studied. METHODS: Seven patients have been administered with 2.0 mg/kg bretylium in 0.25% lidocaine with 100U of heparin three times weekly. A standard intravenous regional technique was used with 250~300 mmHg tourniquet pressure for 30 minutes. Blood pressure and pulse rate were monitored before injection, 1 minute and 5 minutes after injection, immediately before deflation of tourniquet, 1 minute, 5 minutes and 30 minutes after deflation of tourniquet. Pain and temperature evaluations were made before injection and at 1 week after every injection. RESULTS: The increase in skin temperature and decrease in pain score of the affected limb were noted after the use of bretylium in 5 patients out of 7 patients. These clinical effects probably resulted from bretylium,s ability to accumulate in adrenergic nerves and block norepinephrine release. One patient had hypotension immediately after tourniquet deflation. CONCLUSIONS: Intravenous regional bretylium provides significant pain relief for treatment of RSD.