title: The early development of transient and permanent hypothyroidism following radioiodine therapy for hyperthyroid Graves' disease.
abstract: The outcome in 110 patients first treated with radioiodine (mean dose 6.56 mCi) for hyperthyroid Graves' disease in 1980 was reviewed. In 23% of the patients the disease had not been controlled by the initial dose after 3 months, and 17% were given one or two more doses. Within 2 years 65% of the patients required replacement thyroxine therapy. Although about half of the patients were biochemically hypothyroid 3 months after the last dose of iodine 131, this condition was transient in a third of them; five of these patients even became hyperthyroid again. Patients with transient, as opposed to permanent, hypothyroidism at 3 months tended to be clinically euthyroid but to have residual palpable thyroid tissue and only a modest reduction in the serum thyroxine level. It is therefore recommended that patients not overtly hypothyroid 3 months after treatment with 131I be observed still longer before thyroxine replacement therapy is instituted.
mesh_terms: D000328:Adult; D005260:Female; D006111:Graves Disease / Q000628:therapy; D006801:Humans; D007037:Hypothyroidism / Q000209:etiology* / Q000628:therapy; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D013974:Thyroxine / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D007457:Iodine Radioisotopes; D013974:Thyroxine