Effects of low-dose methotrexate with MMI in patients with Graves’ disease: results of a randomized clinical trial

Abstract Context Supplemental methotrexate (MTX) may affect the clinical course of Graves’ disease (GD). Objective Evaluate efficacy of add-on MTX on medical treatment in GD. Design Prospective, open-label, randomized supplementation controlled trial. Setting Academic endocrine outpatient clinic. Patients One hundred and fifty-three untreated hyperthyroid patients with GD. Intervention Patients received MTX 10 mg/d with methimazole (MMI) or MMI only. MTX and MMI were discontinued at months 12-18 in euthyroid patients. Main Outcome Measures Discontinuation rate at months 18 in each group. Results In the MTX with MMI group, the discontinuation rate was higher than the MMI group at months 15-18 (50.0 vs. 33.3%, P=0.043, 95% CI 1.020 to 3.922; and 55.6 vs 38.9%, P=0.045, 95%CI 1.011 to 3.815, respectively). The decrease in TRAb levels in the MTX with MMI group was significant from baseline to months 6 compared to the MMI alone group [MTX+MMI 67.22% (43.12-80.32), MMI 54.85% (33.18-73.76), P= 0.039) and became more significant from months 9 [MTX+MMI 77.79% (62.27-88.18), MMI 69.55% (50.50-83.22), P= 0.035] to months 18 (P < 0.01 in 15–18 months). A statistically significant difference between the levels of TRAb in the MTX with MMI group and the MMI group at 9-18 months. There were no significant differences in the levels of FT3, FT4 and TSH between two groups. No serious drug-related adverse events were observed in both groups(P=0.771). Conclusions Supplemental MTX with MMI resulted in higher discontinuation rate and improvement in decreased TRAb levels to homeostatic levels faster than methimazole treatment alone at months 12-18.