The thionamide DRUGS, i. e. carbimazole and its metabolite methimazole (MMI), and propylthiouracil (PTU) have extensively been used in the management of various forms of hyperthyroidism over the past eight decades. This review aims to summarize different aspects of these outstanding medications. Thionamides have shown their own acceptable efficacy and even safety profiles in treatment of hyperthyroidism, especially GD in both children and adults and also during pregnancy and lactation. Of the ANTITHYROID DRUGS (ATDs) available, MMI is the preferred choice in most situations taking into account its better efficacy and less adverse effects accompanied by once-daily dose prescription because of a long half-life and similar cost. Considering the more severe teratogenic effects of MMI, PTU would be the selected ATD for treatment of hyperthyroidism during pre-pregnancy months and the first 16 weeks of gestation. Recent studies have confirmed the efficacy and safety of long-term MMI therapy with low maintenance doses for GD and toxic multinodular goiter. Despite the long-term history of ATD use, there is still ongoing debate regarding their pharmacology and diverse mechanisms of action, viz. their immunomodulatory effects, and mechanisms and susceptibility factors to their adverse reactions.

Introduction: The aim of this article is to review current information documented on ANTITHYROID drug induced vasculitis.Materials and Methods: MEDLINE was searched for studies between 1960 and 2009 with the key words "ANTITHYROID DRUGS and vasculitis", "ANTITHYROID DRUGS and diffuse alveolar hemorrhage", and "ANTITHYROID DRUGS and glumerolonephritis".Results: Ninety-two articles met the selection criteria. The data obtained showed that 15 to 46% of patients treated with propylthiouracil (PTU) developed anti-neutrophil cytoplasmic antibody (ANCA), in contrast to 0 to 3% of the patients treated with methimazole (MMI), the former being the most often reported for causing vasculitis, a disease seen most commonly in association with Graves' disease. Signs of PTU-induced vasculitis include fever, malaise, anemia, lymphadenopathy, skin lesions, arthralgia, hematuria/proteinuria, diffuse alveolar hemorrhage (DAH), pleural effusion, and crescentic glomerulonephritis. Once PTU-induced vasculitis is determined, the simple withdrawal of PTU usually causes resolution of the symptoms within 1-4 weeks. Overall prognosis of ANTITHYROID drug-induced vasculitis is much better than that of primary vasculitis.Conclusion: ANTITHYROID medications such as PTU can induce (ANCA) -associated vasculitis. Its pathogenesis might be multifactorial. Diagnosis is based on the relationship between clinical vasculitis, and the ANTITHYROID DRUGS prescribed, and the excluding of any other medical states that mimic vasculitis. After the diagnosis, ANTITHYROID DRUGS should be discontinued immediately, and the prognosis is usually good.

Introduction: None of the current available long-term therapies for thyrotoxicosis is ideal, and the choice for each patient must be made individually. The purpose of the present study is to compare the two choices of treatment, the radioiodine and ANTITHYROID drug therapy. Materials and Methods: The study population were thyrotoxic patients treated in Shaheed Beheshti Hospital of Babol between April 1997 to May 2000. Diagnosis of thyrotoxicosis was based on the clinical features and assessment of serum TSH, T4 and T3 levels. Patients with thyroiditis and patients non compliant to regular treatment were excluded. Standard ANTITHYROID drug therapy was started for all patients and continued until the occurence of remission, then tapered off and discontinued. Patients unresponsive to at least six months of drug therapy or patients with disease recurrence after, at least, a three month remission period, were treated with 8-15 mci, of radioiodine and continuation of ANTITHYROID therapy until reaching a euthyroid state. All patients were followed during the treatment period and for at least one year after the beginning of remission. Results: 30 patients (20 females, 10 males) with a mean age of 46±11 years and 44 patients (22 females, 22 males) with a mean age of 37±14 were treated by radioiodine and ANTITHYROID DRUGS. The disease duration in the two age groups was 14±33 and 10.5±15 months respectively (p=NS), and causes of thyrotoxicosis in the two groups were: Graves’ disease in 63% and 79.5%, toxic multinodular goiter in 27% and 11.5% (p<0.05), toxic nodular goiter in 10 and 9% of patients. After a mean follow-up of 19.7±21 months, 60% of patients achieved remission by radiodine and 40% became hypothyroid, whereas 45% of patients achieved remission by ANTITHYROID DRUGS and 55% remained hyperthyroid for as long as 28±19 months. The duration of ANTITHYROID drug therapy in each group was 3.3±4.8 and 13.3±8.3 months, respectively. No drug reaction or recurrence was observed during the remission period of 17.5±19 and 21±18 months. Conclusion: On a short term basis, the outcome of thyrotoxicosis for remission is similar either by radioiodine or ANTITHYROID drug therapy, but development of hypothyroidism in the former and persistance of hyperthyroid state in the latter, gives radioiodine therapy priority.

Background: Patients with Graves’ disease exhibit a considerable rate of relapse after treatment with ANTITHYROID DRUGS and require ablative therapy. Objective: The purpose of this study was to evaluate variables which can be used as prognostic factors in predicting the outcome of Graves’ disease after treatment with ANTITHYROID DRUGS. Methods: Age, sex, duration of ANTITHYROID drug therapy, pretreatment T3 and T4 values, T3 to T4 ratio, size of thyroid gland before and after treatment, and the effect of salt iodination were determined in 439 patients at an endocrine clinic in southern Iran during a 15- year period. The patients included 338 (77%) females and 101(23%) males with a mean age of 34.1±11.2 years. Results: Overall, the relapse rate was 62%. The relapse rates were 58% and 76% in females and males, respectively (P=0.001). The mean age was 35.0±11.6 years in the relapse group (n=275) and 32.6±11.3 in the remission group (n=164) (P=0.03). T4 was 20.4±6.3 and 18.1±5.4 mg/dl in the relapse and remission groups, respectively (P=0.000). In the relapse group, T3 was 443.0±189.5 ng/dl and in the remission group, it was 373.4±182 ng/dl (P=0.009). T3 to T4 ratio was higher in the relapse group (21.8±8.3 vs 18.6±7.0 ng/mg, P<0.005). Larger pre- and post-treatment thyroid size were associated with higher relapse rate (P<0.05 and P=0.001, respectively). Logistic regression analysis showed that male sex, old age, higher pretreatment T4, T3, and T3 to T4 ratio, and larger pre- and post-treatment thyroid size were associated with higher relapse rates. Iodinated salt consumption and duration of treatment beyond 12 months had no effect on the relapse rate.Conclusion: Patients with male gender, older age, higher pretreatment T3, T4 higher T3/T4 ratio, and larger thyroid size before and after treatment have higher risk of relapse.

Background and aim: Three methods are commonly used in hyperthyroidism treatment including drug therapy, radioiodine therapy and surgical operation. Selection of each method is somewhat optional. Radio iodine therapy is indicated when ANTITHYROID DRUGS fail to treat the patient or hyperthyroidism recurs after surgical operation. Radioactive iodine (I131)may have some adverse consequences on salivary glands followed by a decrease or cease in salivary secretion which in turn lead to an increase in dental caries rate. The purpose of this study was to compare the average of CSI and PI and also xerosthemia in patients treated with I131and ANTITHYROID DRUGS.Materials and Methods: Seventy-six patients, after definite hyperthyroidism, diagnosis, were selected and divided into two groups consisting of 30 and 46 patients, depending on treatment plan. Patients of one group were treated using I131radioactive where as for another group ANTITHYROID DRUGS were prescribed.Caries severity index (CSI) and dental plaque index (PI) were measured and compared for all patients before and after treatment. Moreover, patients were studied on xerosthemia and the effects of treatment plan. Data were analyzed using paired samples, independent samples and chi square tests.Results: The findings of this study showed significant differences in CSI and PI rates. before and after 6-8 months I131treatment (p-value=0.016), however, these differences among patients treated by ANTITHYROID DRUGS, were not significant.Conclusion: Xerosthernia was observed more among those treated by I131radioactive. Furthermore, CSI and PI showed significant differences before and after treatment but these effects were not seen while using ANTITHYROID DRUGS.

This study was done to compare the clinical course of hyperthyroid patients with and without anti-thyroid DRUGS immediately post radioactive iodine treatment.Materials and Methods: Patients with mild to moderate hyperthyroidism, aged 18 to 60 years, were divided into 2 groups, those who received RAI plus anti-thyroid (ATD) (propylthiouracil 100 mg q8H) (group A) and those who received RAI only (group B). Fixed doses of 8 mCi 131I were given and symptoms were scored daily for 3 weeks, using 3-severe, 2-moderate, I-mild scores. Descriptive analysis using mean and standard deviation was used to determine the demographic profiles and Mann Whitney Hest for independent samples was utilized to compare the symptoms between the two groups. All statistical tests were pegged at .05 alpha level and p-values less than .05 were considered significant.Results: There were 3 males and 5 females in group A (n=8, mean age: 38±12.82yrs) and 2 males and 6 females in group B, (n=8, mean age: 41.37±15.14yrs). TSH was suppressed in bothgroups and the mean FT4 for group A was 13.87±16.51 pmol/L, and for group B was 28.51±15.86 pmol/L. There was no significant difference in age, FT4 and TSH. Mean scores were as follows: (Group A vs. Group B), week one: 1.36 vs. 1.55 (p=0.01); week two: 1.08 vs. 0.94 (p= 0.110), and week three: 0.71 vs. 0.92 (p= 0.006). A highly significant decrease in symptoms was noted in week three. Conclusion: Analysis of our data showed that patients given ATD immediately post RAI Experienced lesser symptoms of thyrotoxicosis during the first and third week after RAI treatment, favoring treatment with ATD.

Background: Propylthiouracil (PTU) administration is associated with several cases of hepatotoxicity, especially in children. The mechanism (s) of PTU-induced hepatotoxicity is obscure. In the current study, we aimed to assess the effect of PTU on hepatocytes mitochondria in different experimental models.Methods: Mice were treated with PTU (10, 20, 40, 80, and 100 mg/kg, i.p) then, the liver mitochondria were isolated and evaluated. Moreover, liver mitochondria were isolated from normal mice and incubated with increasing concentrations of PTU (10 mM-1 mM). Mitochondrial dehydrogenases activity, mitochondrial membrane potential, mitochondrial swelling, and mitochondrial adenosine triphosphate (ATP) content were monitored.Results: PTU hepatotoxicity was biochemically evident in mice by increased serum biomarkers of liver injury. PTU also caused a decrease in mitochondrial dehydrogenases activity, increased mitochondrial swelling, depleted mitochondrial ATP, and caused mitochondrial depolarization both in vitro and in vivo.Conclusion: Our data suggest mitochondrial dysfunction as a mechanism for PTU-induced hepatotoxicity.

Background and purpose: ANTITHYROID DRUGS (ATD) are the preferred treatment for hyperthyroidism and identification of factors associated with lack of response or recurrence are highly important. The present study was done to evaluate the therapeutic outcomes of hyperthyroid patients attending Sari Academic Endocrine Clinic 2006-2016. Materials and methods: This descriptive study included all hyperthyroid patients. All therapeutic results were recorded and analyzed. Results: In this study, 329 records were studied and 104 patients met the study inclusion criteria. Graves' disease (GD) and toxic adenoma were reported in 94% and 6%, respectively. Among the patients with GD, 30. 5% (21. 7-40. 3%) did not respond to initial ATD treatment and 20% had recurrent GD despite appropriate initial response. Overall, ANTITHYROID DRUGS failure occurred in 50. 5% (40. 45-60. 55%) of the patients. Lower age, lower body mass index (BMI), high thyroid weight, and higher baseline thyroid hormone levels were associated with ATD failure (P <0. 05). Patients with toxic adenomas and patients who did not respond to ATD or those who experienced relapse of hyperthyroidism received radioactive iodine or underwent surgery. Hypothyroidism occurred in 13. 1% of patients with ATD alone, in 66. 7% of those with surgery, and in 79. 4% of the patients who received radioactive iodine (P= 0. 0001). Conclusion: A significant proportion of hyperthyroid patients experience drug failure. Age, BMI, thyroid weight, and basal levels of thyroid hormones are associated with drug treatment failure. Prevalence of hypothyroidism after treatment with radioactive iodine is higher than the drug treatment alone or surgery groups.