Drug-induced thyroid disorders.

Disorders of thyroid hormone metabolism are commonly encountered in clinical practice. Apart from conditions affecting the thyroid gland, thyroid hormone homeostasis may be altered by medications used in varied clinical settings. Drugs may interfere at different steps in thyroid hormone synthesis or secretion leading to hypothyroidism or thyrotoxicosis or may cause changes in hormone binding leading to difficulties in the interpretation of thyroid function tests. These difficulties have been largely overcome by the development of improved diagnostic tools including radio-active uptake studies, estimation of thyroid auto-antibodies and highly sensitive hormone assays.