Block-and-replace regimen versus titration of antithyroid drugs: a recent meta-analysis.

Introduction: Drug therapy for Graves' disease (GD) is the first-line treatment in Europe. The use of a specific regimen for the administration of anti-thyroid drugs (ATDs) is still controversial. The objective was to compare block-and-replace therapy (BRT) with a titration (T) regimen in terms of incidence of overt hypothyroidism and development of Graves' orbitopathy (GO) over 18 months of treatment.

Material and methods: Two databases (PubMed, Cochrane Library) and reference lists were searched. Prospective and retrospective observational cohort studies were included. Data collection and analysis were performed independently by 2 authors.

Results: Two studies with 716 GD patients (40.36% treated with BRT, 59.64% with T regimen) were included. No statistically significant differences were observed between the ATDs regimens used in terms of incidence of overt hypothyroidism during 18 months of treatment [Mantel-Haenszel (M-H) odds ratio (OR): 1.54, 95% confidence interval (CI): 0.75-3.16, p-value = 0.24]. GD patients who followed BRT were less likely to achieve control of thyroid function than patients on T regimen (M-H OR: 0.55, 95% CI: 0.34-0.88, p = 0.01). One study reported fewer thyroid function tests (TFT) during BRT than during the T regimen. The other study included patients without GO at baseline and reported a lower incidence of GO during BRT than in the T regimen (9.1% versus 17.8%), with no statistical difference between the 2 regimens (M-H OR: 0.47, 95% CI: 0.19-1.14, p = 0.10).

Conclusion: BRT may be more useful than the T regimen for patients with complicated GD or for those who required fewer TFTs.