THU669 Time To Achieve Euthyroidism In Graves Disease Using Methimazole In An Urban Population

Disclosure: S.S. Habbsa: None. E. Yunasan: None. A. Krishnan: None. K.M. Munir: None. Context: Previous studies of treatment response in Graves disease have shown that that the mean time to reach euthyroidism with methimazole (MMI) was several weeks to months. In 1987 Okamura et al. concluded that the average period was 6-7 weeks with MMI 30mg daily. Nakamura et al. showed similar data in 2007 (5.8 +/- 4 weeks). These studies were performed in Japanese hospitals over 15 years ago. Limited data exists regarding treatment response times with different doses in a diverse urban population, which may vary with regards to typical dietary patterns, thyroid hormone metabolism and thionamide pharmacokinetics. Objective: The objective of this retrospective chart review was to determine the mean time to achieve euthyroidism with MMI in patients with newly diagnosed Graves disease in Baltimore City. Methods: Patients with Graves hyperthyroidism newly diagnosed in the last 5 years were identified from outpatient endocrine and primary care clinics within the University of Maryland Medical Center healthcare system. Time to achieve euthyroidism (from the start of thionamide therapy to date of euthyroid labs, defined as normal free T4 level) was assessed. Results: 128 patients with recently diagnosed Graves hyperthyroidism were identified (126 patients treated with MMI only and 2 with PTU only). 78% of subjects were female and the mean age at diagnosis was 47 years. The average daily dose of MMI ranged from 2.5mg to 60mg. On average, Free T4 decreased by 0.47 ng/dL per week. The mean time to achieve euthyroidism was 10.1 weeks (8.6, 11.6) overall, similar in males and females. On sub analysis, time to achieve euthyroidism was lower in younger males (age < 40 years) [6.6 weeks (3.9, 9.3)] and older females (age > 40 years) [8.3 (6.9, 9.7)]. Conclusion: The above data may inform expectations for treatment response for newly diagnosed Graves disease, specifically in an urban population on a Westernized diet. Patient forums have shown increasing interest in therapeutic alternatives to thionamides, including specialized diets. This data may help to determine whether other proposed therapies for initial treatment of Graves hyperthyroidism are more or less efficacious. Presentation: Thursday, June 15, 2023