Tratamiento con radioyodo del bocio difuso hipertiroídeo: influencia del pretratamiento con propiltiuracilo / Treatment of diffuse hyperthyroid goiter with radioiodine: influence of propylthiouracil pretreatment

Background: To stabilize Graves disease and deplete the preformed hormone, the use of antithyroid drugs prior 131I therapy has been suggested, specially in those patients with severe thyrotoxicosis and in the elderly. However, PTU may reduce the effectiveness of 131I. Aim: To study the effects of PTU pretreatment before 131I administration. Subjets and methods: A retrospective analysis of the medical records of patients with Graves disease treated with 131I from 1989 to 1997 was made. Of 244 patients with adequate follow-up for at least 12 months after 131I treatment, 142 had not been pretreated and 102 had received PTU prior to 131I therapy. Pretreated patients were distributed according to the number of days that PTU was discontinued before reciving 131I, forming four groups (a=5d, b=6-14 d, c=15-30 d and d=31-60 d). Radioiodine was delivered according to our protocol of 120 µCi per gram of thyroid tissue, as estimated by clinical examination. Therapy was considered successful when laboratory evidence of euthyroidism or hypothyroidism after one year of treatment was obtained and as a failure when undetectable TSH values persisted after 12 months of treatment with 131I. Results: All groups were comparable as to age, gender, goiter size, and 24 h radioiodine uptake. Control of hyperthyroidism was achieved in 76 percent of the non pretreated group. A similar percentage was observed in groups (b), (c) and (d). However, the disease was controlled in only 50 percent of group (a) patients (p <0.003). Conclusions: The therapeutic efficacy of 131I is significantly reduced when the PTU is stopped for only a few days prior to the use of radioiodine. We postulate that PTU has to be discontinued for at least 10 days before radioiodine administration

Tratamiento del hipertiroidismo por enfermedad de Basedow-Graves: visión retrospectiva al cabo de 30 años / Treatment of Basedow-Graves hyperthyroidism: retrospective analysis after 30 years

Background: It is still debated which is the best treatment for Basedow-Graves' hyperthyroidism (BGH). We reviewed 195 patients treated and followed-up during the past 30 years: 88 treated with propylthiouracil (PTU), 70 with 131I and 37 thyroidectomized Aim: to analyze the efficacy of each therapy in terms of achieving euthyroidism and the search of possible indexes for success. Surgery attained euthyroidism in 70.2 percent but has disadvantages; 131I accounted for the highest hypothyroid rate (72.1percent) irrespective of the dose administered; PTU alone was successful in only 26.4 percent but combined with T4, success rose to 62.5 percent (p < 0.025). Suppression test and/or TRAb measurements after 6 mo PTU therapy were used to decide if therapy continued or was changed to other form of treatment. Using this criteria, 87.5 percent of pts with positive results achieved longstanding euthyroidism. Pretreatment predictive indexes were goiter size, T4 levels and 24 h/RAI uptake. Conclusions: As 131I induces hypothyroidism in over 2/3 of pts and surgery besides its cost is not devoid of serious complications, we advocate for the use of PTU as first line therapy; combined treatment (PTU + T4) seems promising. If after 6 mo on PTU, TRAb or Suppression test do not improve, we recommend 131I or surgery