title: [The effect of propylthiouracil on the efficacy of radioiodine (I-131) therapy in graves hyperthyroidism].
abstract: Aiming at evaluating the effect of antithyroid drugs on the efficacy of radioiodine treatment (RAI) we retrospectively analyzed 226 patients with Graves disease hyperthyroidism submitted to RAI between 1990 and 2001: 58 patients without any antithyroid drug (ATD) prior to RAI, 119 patients using propylthiouracil (PTU) and 49 patients using methimazole (MMI) prior to RAI. Clinical and laboratory parameters 1 year after RAI defined their clinical status (cured or not cured). High serum free T4 and 131-iodine uptake were negatively related with cure as well as lower RAI doses (mCi) and larger goiters (p< 0.05). The percentage of cured patients on PTU prior to RAI was 70.2% (84/119), while those on MMI was 85.7% (42/49), and 84.5% (49/58) of those without ATD prior to RAI (p= 0.034). On logistic regression analysis, free T4 > 4 ng/dl, large goiter, RAI dose < 10 mCi and PTU prior to RAI were related to lower cure rates. Compared to patients with no ATD prior to RAI, we concluded that the previous use of PTU implies in higher failure rates after RAI (OR= 3.13), an effect not observed in patients on MMI (OR= 1.28).
authors.affiliation: Serviço de Endocrinologia, Departamento de Ciências Médicas, Universidade Federal do Rio de Janeiro. marcusleitao@terra.com.br
authors.forename: Marcus V L
authors.initials: MV
authors.lastname: de Souza
authors.forename: Alexandru
authors.initials: A
authors.lastname: Buescu
authors.forename: Mario
authors.initials: M
authors.lastname: Vaisman
authors.forename: Honomar F
authors.initials: HF
authors.lastname: de Souza
authors.forename: Ronir Raggio
authors.initials: RR
authors.lastname: Luiz
mesh_terms: D000328:Adult; D013956:Antithyroid Agents / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006111:Graves Disease / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy / Q000532:radiotherapy; D007457:Iodine Radioisotopes / Q000008:administration & dosage*; D016015:Logistic Models; D008297:Male; D008713:Methimazole / Q000627:therapeutic use; D011441:Propylthiouracil / Q000627:therapeutic use*; D011837:Radiation-Protective Agents / Q000627:therapeutic use*; D011859:Radiography; D012189:Retrospective Studies; D013960:Thyroid Function Tests; D013963:Thyroid Hormones / Q000097:blood; D016896:Treatment Outcome
chemical_list: D013956:Antithyroid Agents; D007457:Iodine Radioisotopes; D011837:Radiation-Protective Agents; D013963:Thyroid Hormones; D008713:Methimazole; D011441:Propylthiouracil