HYPERTHYROIDISM AND THIOURACIL

Abstract

The risks of the 2 procedures[long dash]medical and surgical[long dash]remain to be evaluated by more cases treated over a longer period of time. In the series of 50 cases treated with thiouracil at the University Hospital, no serious complications were encountered during a period extending from 1-10 mos. No case of drug intolerance, idiosyncrasy, or refractoriness was found. Thus far leukopenia has been the only serious effect and this might represent an early step in the development of agranulocytosis. The depressant effect of the drug on the hematopoietic system must be anticipated throughout the course of treatment. No case failed to respond to the drug, but some responded more satisfactorily than others. In general, the higher the initial BMR, the more dramatic was the response. The effect of vits., sedation, and rest enhance the efficiency of thiouracil but have little intrinsic curative properties. No case has required operation. The patient coming to operation is treated in the same manner as one with simple colloid goiter, with the exception that measures are taken to control the greater vascularity encountered in a thyroid treated with thiouracil. Postoperatively, Na sulfadiazine is given paren-terally if there is any atelectasis, significant elevation of temperature, or sign of incipient thyroid storm. There have been no postoperative complications referable to treatment with thiouracil. Microscopic sections of thyroid glands treated with thiouracil have exhibited varying degrees of hyperplasia and colloid content. It is believed that the thiouracil effect is brought about by depression of normal enzyme reactions of tissues in general but especially of the pituitary (leading to suppression of synthesis of thyroid stimulating hormone) and of the thyroid (leading to inhibition of iodine uptake). Less hyperplasia and more colloid have been noted in sections of two glands treated with thiouracil and thyroxin. Sections of two glands treated with thiouracil and I were in every way similar to thyroids treated with thiouracil alone. Over half of the 50 cases have received from 1 gr. of desiccated thyroid to 1/80 gr. of thyroxin daily, the dose being dependent on the degree of exophthalmos present. In no case did the thiouracil effect appear to be inhibited by giving thyroid substance. There is a trend toward a state of normal endocrine balance on thiouracil therapy alone, but the restoration is brought about more quickly, more completely, and with less frequent unpleasant side reactions when thyroid substance is given in combination with thiouracil. Four cases which have been observed for the past 8 months have required no medication of any sort for the past 3 months and as yet appear to be in a state of normal physiologic equilibrium with basal metabolic rates in the range of [plus or minus] 12 per cent. Those patients who have relapsed because treatment was discontinued too soon or because of intercurrent infection or emotional stress, have reacted in the same manner as have patients who have developed recurrent hyperthyroidism following thyroidectomy. Such patients have responded as satisfactorily to the second round of medication with thiouracil and thyroxin as they did at the beginning of treatment. Because of the cyclic nature of Graves'' disease the remissions obtained by any treatment must not be confused with "cures" except in that small group of patients who have fallen victims to the malady because of a definite etiologic factor which can be removed.