Endocrine Abstracts

Introduction

Antithyroid drugs are widely used in the therapy of hyperthyroidism. This review (update of Cochrane review: Antithyroid drug regimen for treating Graves' hyperthyroidism. In: The Cochrane Library, Issue 4, 2003; with 4 additional trials) assesses the effects of dose, regimen and duration of antithyroid drug therapy for Graves' hyperthyroidism.

Methods

The Cochrane Controlled Trials Register, MEDLINE, EMBASE, BIOSIS, CINAHL, HealthSTAR, the Current Controlled Trials and reference lists were searched. Data were extracted and the trial quality was assessed. Pooling of data for primary outcomes and selected exploratory analyses were undertaken.

Results

Twenty three randomised trials (3155 participants) were included. The four additional trials influenced the results of the two subgroups reported below. Twelve trials examined the effect of Block-Replace versus Titration regimen. The relapse rates were similar in both groups at 51% in the Block-Replace group and 54% in the Titration group (Peto OR = 0.86, 95% confidence interval (CI): 0.68-1.08). The number of participants reporting rashes was significantly higher in the Block-Replace group (10%, 63/616) as compared to the Titration group (5%, 31/622) (OR = 2.62, 95% CI: 1.20-5.75). The number of participants withdrawing due to side effects was also significantly higher in the Block-Replace group. (16%, 58/353) compared to 9%, 30/344 in the Titration group (Peto OR = 2.03, 95% CI: 1.30-3.18).

Four trials considered the continuation of thyroxine alone after completion of antithyroid medication. There was no significant difference in the relapse rates between the groups after 12 months follow-up with relapse rates being 31% (88/282) with thyroxine and 29% (82/284) with placebo (Peto OR = 1.15, 95% CI: 0.79-1.67).

Conclusions

The Titration regimen had fewer adverse effects than the Block-Replace regimen and was found to be equally efficacious. There does not appear to be any benefit in continued thyroxine treatment following antithyroid drug therapy.