TOXIC REACTIONS TO THIOURACIL

Abstract

The introduction of thiouracil in the treatment of thyrotoxicosis has occasioned renewed interest in the nonsurgical therapy of the disease. In 1941 Kennedy and Purves 1 observed that rapeseed and allyl thiourea were potent goitrogens. Subsequently the MacKenzies and McCollum 2 and Astwood 3 showed that thiourea and thiourea derivatives, especially 2-thiouracil, produced morphologic thyroid hyperplasia associated with inhibition of hormone production. Astwood 4 first employed thiouracil in the treatment of patients with toxic goiter. This chemical compound is 2-thiouracil with the structural formula of NHCSNHCOCHCH. He found that the drug pro duced complete remission of symptoms and return of the basal metabolic rate to normal in most cases. These findings were confirmed by Williams and Bissell. 5 Our own experience is in accord with these reports. Early observations quickly showed the toxicity of thiouracil. Astwood, 6 reporting the first 30 cases of hyperthyroidism treated with the drug, noted 1