Abnormal thyroid function tests in children on ethionamide treatment [Short communication]

Ethionamide (ETH) treatment may cause hypothyroidism. Clinical data, serum thyroid stimulating hormone (TSH) and free thyroxine (fT4) levels were retrospectively assessed in 137 children receiving anti-tuberculosis treatment including ETH. Abnormal thyroid function tests (TFTs) were recorded in 79 (58%) children: elevated serum TSH and suppressed fT4 (n = 30), isolated elevated serum TSH (n = 20), isolated low serum fT4 (n = 28) and isolated low TSH (n = 1). The risk for biochemical hypothyroidism was higher for children on regimens including para-aminosalicylic acid and in human immunodeficiency virus infected children. TFT abnormalities are frequent in children on ETH and are mainly due to primary hypothyroidism or euthyroid sick syndrome.