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

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.

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.

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).

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