Three euthyroid patients with Hashimoto's
thyroiditis developed
hypothyroidism after the administration of
rifampin. We studied 67 patients with
tuberculosis. All of them were treated with
rifampin. Of the 67 patients, 42 had negative tests for anti-thyroid
antibodies (ATA) and 25 had positive tests for ATA. The diagnosis of Hashimoto's
thyroiditis was made on the basis of positive tests for ATA. After the administration of
rifampin, TSH levels were not significantly altered in all of the former 42 ATA-negative patients and in 22 of the latter 25 ATA-positives, but TSH levels increased in the other three (Patients 1, 2 and 3) of the latter 25 ATA-positives. Three euthyroid Hashimoto's patients (Patients 1, 2 and 3) developed
hypothyroidism after the administration of
rifampin. This
rifampin-induced
hypothyroidism resolved in each, once
rifampin was discontinued. A) Patient 1: a 62-yr-old man with
lymphoma had
pulmonary tuberculosis. After the administration of
rifampin, serum TSH increased to 170 mU/l; B) Patient 2: a peritoneal-biopsy specimen containing Langhans' giant cells led to a diagnosis of
tuberculous peritonitis in a 66-yr-old woman with
ascites. After the administration of
rifampin, TSH increased to 12.4 mU/l; C) Patient 3: a 56-yr-old woman with a
liver abscess and
lymphadenopathy underwent lymph-node biopsy that showed Mycobacterium tuberculosis with caseating
granulomas. After the administration of
rifampin, TSH increased to 21.3 mU/l. After its administration, Patients 1, 2 and 3 developed
hypothyroidism, and received T4. When
rifampin was discontinued, the
hypothyroidism resolved. After the course of
rifampin-
therapy had been completed, T4 was discontinued. At-risk patients who receive
rifampin may become hypothyroid.