title: Transient hypothyroidism after iodine-131 treatment of thyrotoxicosis.
abstract: Thirty consecutive patients with thyrotoxicosis were followed up at monthly intervals for 6 months after treatment with iodine-131. Serum total T4, serum total T3, and serum TSH response to TRH were measured at each review. Biochemical evidence of hypothyroidism (low T4 raised basal TSH) developed in 18 patients 1-4 months after treatment. In 5 of these patients, symptoms and signs of hypothyroidism remained absent or minimal and spontaneous recovery of thyroid function occurred during the ensuing 2 months. If biochemical hypothyroidism occurs during the first 6 months after radioiodine therapy, it is recommended that T4 replacement be withheld for 2 months unless the severity of symptoms demands treatment.
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy*; D007037:Hypothyroidism / Q000097:blood / Q000139:chemically induced*; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D007457:Iodine Radioisotopes; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine