Hyperthyroidism is a common endocrine disease. Although thionamide antithyroid drugs are the cornerstone of hyperthyroidism treatment, some patients cannot tolerate this drug class because of its serious side effects including agranulocytosis, hepatotoxicity, and vasculitis. Therefore, nonthionamide antithyroid drugs (NTADs) still have an important role in controlling hyperthyroidism in clinical practice. Furthermore, some situations such as thyroid storm or preoperative preparation require a rapid decrease in thyroid hormone by combination treatment with multiple classes of antithyroid drugs. NTADs include iodine-containing compounds, lithium carbonate, perchlorate, glucocorticoid, and cholestyramine. In this narrative review, we summarize the mechanisms of action, indications, dosages, and side effects of currently used NTADs for the treatment of hyperthyroidism. In addition, we also describe the state-of-the-art in future drugs under development including rituximab, small-molecule ligands (SMLs), and monoclonal antibodies with a thyroid-stimulating hormone receptor (TSHR) antagonist effect.

Background: Thyroid cancer is among the fastest growing malignancies; almost fifty-percent of these rapidly increasing incidence tumors are less than or equal to 1cm in size, termed papillary thyroid microcarcinoma (PTMC). The management of PTMC remains a controversy due to differing natural history of these patients. Epithelial cell adhesion molecule (EpCAM) is comprised of an extracellular domain (EpEx), a single transmembrane domain and an intracellular domain (Ep-ICD). Our group reported nuclear Ep-ICD correlated with poor prognosis in thyroid cancer (Ralhan et al., BMC Cancer 2010,10:331). Here in, we hypothesized nuclear and cytoplasmic accumulation of Ep-ICD and loss of membranous EpEx may aid in distinguishing metastatic from non-metastatic PTMC, which is an important current clinical challenge. To test our hypothesis, Ep-ICD and EpEx expression levels were analyzed in PTMC and the staining was correlated with metastatic potential of these carcinomas. Methods: Thirty-six PTMC patients (tumor size 0.5 - 1cm; metastatic 8 cases and non-metastatic 28 cases) who underwent total thyroidectomy were selected. The metastatic group consisted of patients who developed lymph node or distant metastasis at diagnosis or during follow up. The patients’ tissues were stained for Ep-ICD and EpEx using domain specific antibodies by immunohistochemistry and evaluated. Results: PTMC patients with metastasis had higher scores for nuclear and cytoplasmic Ep-ICD immunostaining than the patients without metastasis (1.96 ± 0.86 vs. 1.22 ± 0.45; p = 0.007 and 5.37 ± 0.33 vs. 4.72 ± 1.07; p = 0.016, respectively). Concomitantly, the former had lower scores for membrane EpEx than the non-metastatic group (4.64 ± 1.08 vs. 5.64 ± 1.51; p = 0.026). An index of aggressiveness, Ep-ICD subcellular localization index (ESLI), was defined as sum of the IHC scores for accumulation of nuclear and cytoplasmic Ep-ICD and loss of membranous EpEx; ESLI = [Ep − ICD_nuc + Ep − ICD_cyt + loss of membranous EpEx]. Notably, ESLI correlated significantly with lymph node metastasis in PTMC (p = 0.008). Conclusion: Nuclear and cytoplasmic Ep-ICD expression and loss of membranous EpEx were found to correlate positively with metastasis in PTMC patients. In addition, ESLI had the potential to identify metastatic behavior in PTMC which could serve as a valuable tool for solving a current dilemma in clinical practice.

Purpose: To evaluate metformin’s benefit on the incidence and survival of hepatocellular carcinoma (HCC) in cirrhosis with type 2 diabetes mellitus (T2DM) patients. Patients and Methods: We conducted a retrospective study from 2006 to 2019. The patients were assigned to metformin exposure if they administered metformin at least 3 months after diagnosis of cirrhosis. The outcomes were incidence and survival of HCC in T2DM with cirrhosis treated with metformin compared with those who were not treated with metformin. For the incidence of HCC, the follow-up time was 5 years after cirrhosis was diagnosed. For the survival of HCC, we censored for vital status in June 2019. Results: Of 1061 patients, the patients were divided into 719 patients with metformin exposure and 342 in metformin non-exposure. In metformin exposure, 125 patients (17.4%) developed HCC. In metformin non-exposure, 128 patients (37.4%) developed HCC. Metformin exposure had a significantly lower risk of developing HCC in multivariate analysis HR 0.48 (0.36– 0.61); P< 0.001. For the survival of HCC, 327 patients were recruited. One-hundred and sixty-two patients were in metformin exposure and 165 patients were in metformin non-exposure. Sixty patients (37%) in metformin exposure died, while 84 patients (50.9%) in metformin non-exposure died. The median survival of metformin exposure and metformin non-exposure were 6.9 years and 3.88 years, respectively; P=0.003. In univariate analysis, the metformin exposure was significantly associated with better survival than in the non-exposure group, HR 0.63 (0.45– 0.88); P=0.006. No significant difference was observed in multivariate analysis between two groups, HR 1.07 (0.74– 1.54); P=0.72. Conclusion: Metformin exposure was associated with a lower incidence of HCC in cirrhosis with T2DM patients and seemed to extend survival. Continuing metformin in patients with cirrhosis with T2DM should be considered if there was no contraindication.

Background. Previous studies used unequal or high daily dosages of methimazole (MMI) to compare the efficacy of once daily dose regimen (OD-MMI) with that of divided daily doses regimen (DD-MMI) in inducing euthyroidism. Objectives. To compare the efficacy of OD-MMI to that of DD-MMI using low daily dosage of MMI in inducing euthyroidism. Methods. Fifty patients with clinically nonsevere Graves’ hyperthyroidism were randomized to be treated with 15 mg/day OD-MMI or 15 mg/day DD-MMI. Results. 21 cases (84%) in OD-MMI and 23 cases (92%) in DD-MMI were eligible for analyses. During the treatment, there was no difference in baseline characteristics, serum FT3 and FT4 reductions, and cumulative rate of achieving euthyroidism (4.8% versus 4.3%, 28.6% versus 34.8%, 71.4% versus 82.6%, and 85.7% versus 87.0% at 2, 4, 8, and 12 weeks, resp.) between both regimens. Hypothyroidism developed in DD-MMI significantly more than in OD-MMI (17.4% versus 0%, p<0.05). Conclusions. Treatment with MMI at a low daily dosage of 15 mg/day OD-MMI is as effective as DD-MMI in the reduction of serum thyroid hormone levels and induction of euthyroidism. The OD-MMI regimen is preferable to the DD-MMI regimen in the treatment of clinically nonsevere Graves’ hyperthyroidism. This trial is registered with Thai Clinical Trials Registry: TCTR20170529001.