Methimazole plus levothyroxine for treating hyperthyroidism in children: a systematic review and meta-analysis

Hyperthyroidism is a disease of excessive synthesis and secretion of thyroid hormones, and there is a lack of studies that have systematically evaluated the efficacy of the combination in treating hyperthyroidism. This study aimed to systematically evaluate the effectiveness and safety of methimazole combined with levothyroxine for treating hyperthyroidism in children.

We searched PubMed, CNKI, Wanfang Database, EMBASE, Web of Science, and other online electronic databases to find correlation studies of methimazole combined with levothyroxine in treating hyperthyroidism in children from 2010 to 2021. Meta-analysis was performed using Stata 16 software.

Finally, 15 relevant articles were included comprising 1,718 pediatric patients. Meta-analysis results indicated that compared with methimazole alone (control group), the experimental group administered methimazole + levothyroxine had no evident difference in the level of thyroid-stimulating hormone [standardized mean difference (SMD) =-0.34, 95% confidence interval (CI): -1.02, 0.35, P=0.33], but notably improved the efficacy of clinical treatment of hyperthyroidism in children [odds ratio (OR) =5.77, 95% CI: 2.62, 12.74, P<0.001]. Meanwhile, the experimental group had lower adverse reaction rates (OR =0.28, 95%CI: 0.19, 0.40, P<0.001), free triiodothyronine (FT3) level (SMD =-0.85, 95% CI: -1.57, 0.13, P=0.02), free tetraiodothyronine (FT4) level (SMD =-0.94, 95% CI: -1.59, -0.30, P=0.004) and reduced thyroid volume (SMD =-1.3, 95% CI: -1.67, 0.93, P<0.001).

Using methimazole + levothyroxine to treat hyperthyroidism in children can raise the levels of FT3 and FT4, reduce the thyroid volume, improve clinical efficacy, and lower the adverse reaction rate of patients.