Disturbances of thyroid function tests by drugs.

Commonly prescribed drugs can variously cause changes in measuring serum T3 and T4 concentrations. Thus spuriously normal thyroid hormone levels may result in moderate hypo- or hyperthyroidism, or the influence of pharmacological substances may lead to a false diagnosis of thyroid disease in euthyroid subjects. On the other hand numerous pharmacological agents, especially those interacting with neurotransmitters, may influence TSH secretion, too. While generally such drug-induced abnormal thyroid tests do not correspond to clinical features of thyroid dysfunction, iodine containing drugs, especially amiodarone, may result in overt thyroid disease.