Sympathetic Blockade in Hyperthyroidism

The antithyroid drugs propylthiouracil and methimazole are commonly used in the treatment of hyperthyroidism. The incidence of overall toxic drug reactions to these antithyroid drugs have been reported to vary from 6% to 9%1-3; however, the incidence of serious side effects, including agranulocytosis, is approximately 0.3% to 0.6% in a large series.4Subsequent management of the hyperthyroidism in those patients who develop drug toxic reaction becomes a problem, especially in the younger age group where alternative forms of treatment are limited. During the past few years sympathetic blocking drugs, including guanethidine sulfate5and propranolol hydrochloride,6-9have been advocated as ancillary agents in the treatment of hyperthyroidism. The use of propranolol as a means of preparing hyperthyroid patients for thyroidectomy has also been suggested.10This report details the course of three hyperthyroid patients who developed toxic reactions to antithyroid drugs and in whom thyroidectomy was successfully