Treatment of Hyperthyroidism With Propylthiouracil

T H E current differences of opinion regarding the best form of treatment for hyperthyroidism are a reflection of the fact that of the several effective methods which are available, none is devoid of significant disadvantages. Experience with the use of antithyroid compounds is sufficient to show that this is a highly effective form of treatment, but extensive clinical trials have been carried out only with one such drug, thiouracil. The disadvantage attending the use of this compound relates almost exclusively to its side effects,1 the drug fever syndrome or some variant of it and agranulocytosis. The former reaction usually precludes the continued use of the drug; the latter is of such severity as sometimes to cause death. These reactions together with milder ones less certainly related to the medication have been encountered in about one of every 10 patients treated with thiouracil. With the aim of finding more satisfactory agents for clinical use many hundred compounds have been tested in animals. To date, the most active substance encountered has been propylthiouracil, and it has therefore been