Retrospective evaluation of the diagnosis and treatment methods of thyroid disorders induced by amiodarone

Objective: Amiodarone is an antiarrhythmic drug widely used in the treatment of cardiac arrhythmias, which can cause side effects on the thyroid, such as hypothyroidism and hyperthyroidism. This study aims to identify potential risk factors for predicting the side effects amiodarone may have on the thyroid, to determine tools that can be used in diagnosis and classification, and to retrospectively review treatment methods. Method: Data from a total of 301 patients, with a mean age of 65.67±12.91 years, of whom 105 (34.9%) were women, who started amiodarone therapy under the Department of Cardiology at Akdeniz University Faculty of Medicine and used amiodarone for at least 3 months, were reviewed. Findings: Hypothyroidism was detected in 71 (23.6%) and hyperthyroidism in 80 (26.6%) of the patients included in the study. In all groups, sT4 levels increased while sT3 levels decreased 3 months after starting amiodarone treatment. In patients who developed hypothyroidism, TSH levels increased significantly 3 months after treatment, whereas in those who developed hyperthyroidism, TSH levels decreased significantly. The proportion of male patients was found to be significantly higher (72.5%) among those who developed hyperthyroidism, whereas the gender distribution was similar in patients who developed hypothyroidism. The thyroid volume of patients who developed hyperthyroidism was found to be significantly higher (27.72±19.48 cc) compared to the other two groups. The mean duration of side effects in patients with hyperthyroidism [13.5 (7-24.5) months] was significantly longer than in those with hypothyroidism [5 (3-16) months]. Type 1 AIT was detected in 63.7% and Type 2 AIT in 36.3% of the patients who developed hyperthyroidism. Conclusion: It is difficult to predict thyroid dysfunctions that may be caused by amiodarone. Therefore, every patient starting amiodarone therapy should be 56 evaluated for risk factors of thyroid dysfunction and closely monitored. Since hyperthyroidism and hypothyroidism can trigger cardiac arrhythmias, they should be diagnosed early, classified quickly and accurately, and the treatment process should be planned promptly. If amiodarone is indispensable for managing cardiac arrhythmias, patients should also be evaluated for potential ablative treatment options. Key Words: Amiodarone, Hyperthyroidism, Hypothyroidism, Cardiac Arrhythmias, Thyrotoxicosis