• Twenty-five patients who had a variety of painful conditions in the extremities with some of the characteristics of causalgia were treated with two drugs, hexamethonium and Dibenzyline, commonly classified as sympathetic blocking agents. The hexamethonium was given intravenously; if it relieved the pain, it was followed by Dibenzyline given by mouth.
Six of the patients were completely and permanently relieved of the pain in this way. In 13 there was complete relief during the period of medication but some recurrence of pain thereafter.
Those patients who were not helped by this medication likewise had poor results from later surgical sympathetic blocking or sympathectomy.
These drugs are therefore useful as giving either permanent relief of causalgia or temporary alleviation with valuable prognostic indications.