Studies of Thyroid and Sympathetic Nervous System Interrelationships. II. Effects of Guanethidine on Manifestations of Hyperthyroidism1

Abstract

The effect of guanethidine on the manifestations of hyperthyroidism was evaluated in 27 patients. The average oral maintenance dose was 80 mg daily. Significant improvement in the cardiovascular, neuromuscular and metabolic manifestations was noted within the 1st week of treatment. No effect upon the thyroid gland hyperactivity per se or upon the concentration of circulating thyroid hormone was noted. The results provide further evidence of the physiologic interaction between the sympathetic catecholamines and the thyroid hormones. The use of sympatholy tic drugs can be recommended for prompt control of the symptoms and signs of thyrotoxicosis as an adjunct to therapy directed at control of the intrinsic hyperthyroid state. Guanethidine appears to be an effective and useful sympatholytic drug for this purpose.