[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: Marcus V L de Souza, Alexandru Buescu, Mario Vaisman, Honomar F de Souza, Ronir Raggio Luiz
• Journal: Arquivos brasileiros de endocrinologia e metabologia (Arq Bras Endocrinol Metabol) Vol. 50 Issue 6 Pg. 1088-95 (Dec 2006) ISSN: 0004-2730 [Print] Brazil
• Vernacular Title: Efeito do propiltiouracil sobre a eficácia da dose terapêutica de iodo radioativo (I-131) no hipertiroidismo por doença de graves.
• PMID: 17221116 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Antithyroid Agents
• Iodine Radioisotopes
• Radiation-Protective Agents
• Thyroid Hormones
• Methimazole
• Propylthiouracil

Topics

• Adult
• Antithyroid Agents (therapeutic use)
• Combined Modality Therapy
• Dose-Response Relationship, Radiation
• Female
• Graves Disease (diagnostic imaging, drug therapy)
• Humans
• Hyperthyroidism (drug therapy, radiotherapy)
• Iodine Radioisotopes (administration & dosage)
• Logistic Models
• Male
• Methimazole (therapeutic use)
• Propylthiouracil (therapeutic use)
• Radiation-Protective Agents (therapeutic use)
• Radiography
• Retrospective Studies
• Thyroid Function Tests
• Thyroid Hormones (blood)
• Treatment Outcome