The efficiency and safety of methimazole and propylthiouracil in hyperthyroidism A meta-analysis of randomized controlled trials

Purpose: The aim of this study was to evaluate the efficiency and safety of methimazole (MMI) and propylthiouracil (PTU) in the treatment of hyperthyroidism. Methods: Articles were searched through the PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, and QVIP. The primary outcomes were clinical efficacy and thyroid hormone levels in MMI and PTU groups. The secondary outcomes were liver function indexes and adverse reactions in MMI and PTU groups. Results were expressed as weighted mean difference (WMD) or odds ratio (OR) with 95% confidence intervals (CIs). The Begg test was applied to assess the publication bias. Results: Totally, 16 randomized controlled trials were retained in this meta-analysis with 973 patients receiving MMI and 933 receiving PTU. The levels of triiodothyronine (T-3) (WMD = -1.321, 95% CI: -2.271 to -0.372, P = .006), thyroxine (T-4) (WMD = -37.311, 95% CI: -61.012 to -13.610, P = .002), Free T3 (FT3) (WMD = -1.388, 95% CI: -2.543 to -0.233, P = .019), Free T-4 (FT4) (WMD = -3.613, 95% CI: -5.972 to -1.255, P = .003), and the risk of liver function damage (OR = 0.208, 95% CI: 0.146-0.296, P < .001) in the MMI group were lower than those in the PTU group. The thyroid-stimulating hormone level (WMD = 0.787, 95% CI: 0.380-1.194, P < .001) and the risk of hypothyroidism (OR = 2.738, 95% CI: 1.444-5.193, P = .002) were higher in the MMI group than those in the PTU group. Conclusions: Although MMI might have higher risk of hypothyroidism than PTU, the efficacy of MMI may be better than PTU in patients with hyperthyroidism regarding reducing T-3, T-4, FT3, and FT4 levels, decreasing the risk of liver function damage and increasing the level of thyroid-stimulating hormone. Register number: osf.io/ds637 ( https://osf.io/search/).