Amiodarone-induced thyroid dysfunction--clinical picture. Study on 215 cases

The purpose of this study was to investigate the prevalence and the clinical-evolutionary implications of thyroid damage in patients treated with amiodarone in the Cardiology Clinic of the "Sf. Spiridon" University Hospital of Iasi.

The study included a group of 215 patients, 90 men and 125 women with ages between 35 and 87, hospitalized in the Cardiology Clinic between 2004 and 2014, who received amiodarone treatment, in most cases for the prophylaxis of various arrhythmias, both supra-ventricular and ventricular.

In 27.80% of the patients, the assessment of the thyroid function was imposed by the appearance of the clinical picture characteristic for hypo- and hyperthyroidism, and for 72.19% it was carried out as a routine examination. Amiodarone-induced hypothyroidism was clinically diagnosed in 20.85% of the patients. Hyperthyroidism occurring during treatment with Cordarone was found in 6.95% of the patients. The confirmation of the diagnosis of amiodarone-induced thyroid dysfunction was based on hormonal dosages (TSH, FT4 and even FT3 in some cases), on the endocrinological clinical consultation and on the imaging study--i.e. thyroid echography.

Amiodarone-induced thyroid dysfunction is relatively rare compared to the number of patients treated with this anti-arrhythmic drug (27.8%) from the group under study. Thyroid dysfunction, regardless of the type (with hypo or hyper-function), represents a negative element in the evolution of patients with pre-existing heart diseases, not only by aggravating the clinical picture of the basic illness, but also by the necessity of permanently reviewing the therapeutic scheme imposed also by the association of thyroid dysfunction medication, according to case.