DRUG TREATMENT FOR THYROTOXICOSIS MICL JOURNALpatients who do not desire surgery and cannot have radioiodine, and is used with many other patients for varying reasons. We would suggest that the procedure outlined above, while simplifying the management of such cases, diminishes the risk of goitrogenesis and of worsening of the eye signs without impairing the therapeutic effects. t We should expect the procedure to be similarly suitable for preparing the thyrotoxic patient for operation, provided iodide is given in addition over the last two weeks. We are at present investigating the latter method. Summary A preliminary report is-made of the practicability of treating thyrotoxicosis with both methylthiouracil and thyroxine to simplify the control of dosage. The results were apparently as satisfactory as the published results obtained with antithyroid drugs alone.A basic standard dosage was used (enough methylthiouracil to control all but exceptional thyrotoxicosis and the minimal normal thyroxine requirements-that is, methylthiouracil, 50 mg., and L-thyroxine, 1 mg., thrice daily); this standard dosage, unaltered, suffices for the maintenance treatment of most patients, provided signs of goitre enlargement are sought and when seen are countered by giving additional thyroxine. If the adequacy of the control of thyrotoxicosis is doubted the methylthiouracil dose can be increased.Among the first 32 cases completing a course of nine or more months of such treatment, in 18 (56%) the thyrotoxicosis was still fully re:mitted one year later, in no case had the eye signs significantly worsened, and in all except one the goitre size had decreased.We are indebted to Glaxo Laboratories Ltd., who supplied the pills for this trial.