Minimum Dosage of Thiourea, Given Together With Iodine Medication, Necessary for the Production and Maintenance of a Remission in Hyperthyroidism 1

Abstract

It has been shown that thiourea in amounts smaller than those recommended for thiouracil can produce a satisfactory remission in hyperthyroidism (1). The thyroid-depressant effect is enhanced if thiourea is used in combination with strong solution of iodine (2, 3, 4). The administration of these two substances together results in a more rapid and more profound drop in the concentration of serum precipitable iodine than that observed with thiourea alone. Symptoms and signs of thyroid overactivity disappear along with or soon after the fall in serum precipitable iodine. Continued administration of thiourea, however, in the dosage initially used to produce a remission (280 to 210 mgm. daily) -ultimately results in hypothyroidism in a number of patients. Ingestion of desiccated thyroid is followed by disappearance of the hypothyroidism and the serum precipitable iodine concentration returns to normal.These facts suggest that the dosage initially employed was unnecessarily large. The present study arose from an attempt to avoid hypothyroidism by the use of the minimum effective dose of thiourea. To determine the magnitude of this, the effects of small doses of thiourea, 0.075 to 0.015 gram daily, together with iodine solution in inducing and maintaining a remission in hyperthyroidism have been studied. Results obtained with iodine medication alone, and those with amounts of thiourea greater than 0.075 gram are included for purposes of comparison. MATERIALS AND METHODSData are presented on 4 groups of hyperthyroid subjects, some with diffuse goiter and some with adenomata. With but few exceptions the patients were not hospitalized. The diagnosis of thyroid overactivity was based primarily upon the presence of a concentration of serum 'Aided by a grant from the Fluid Research Fund,

An Evaluation of Lithium as an Adjunct to Carbimazole Treatment in Acute Thyrotoxicosis

“…The carbimazole-Li and carbimazole-KI regimes appear equally effective in this respect. However, iodide has the disadvantage of delaying the subsequent administration of radioiodine therapy and there is also the risk of producing an exacerbation of the thyrotoxicosis (Winkler et al 1947) if the patient omits or discontinues the carbimazole. It is also our impression that the sedative effect of lithium is a further advantage in the treatment of severe thyrotoxi¬ cosis although a double blind trial would be necessary to confirm this.…”

The Use of Lithium in the Treatment of Thyrotoxicosis

“…7). The only therapeutic agents that inhibits release of thyroid hormone directly is inorganic iodine, but problemis created by its use include interference witlh a number of diagnostic nmeasurements of thyroid function, a significant incidence of poor response or even exacerbated thyrotoxicosis (8), and delay of 131J therapy. We therefore investigated Li' as a potential therapeutic agent in patients in whom a prompt decrease in thyroid hormone levels is required (1).…”

Thiourea and Thiourea Derivatives

“…After initial doses of 2 -3 g/d, dosages of 100 -200 mg/d were administered, and finally 25 -70 mg was recommended as the daily dose. Doses of 10 -15 mg/d were ineffective in 5 of 8 people [79]. Its use in therapy has been frequently associated with side effects, e.g., gastrointestinal disorders, pain in the muscles and joints, leukopenia, fever, and reddening of the skin.…”