[Two cases of multi-drug-resistant pulmonary tuberculosis with para-aminosalicylic acid (PAS)-induced hypothyroidism].

Two cases of multi-drug-resistant pulmonary tuberculosis with para-aminosalicylic acid (PAS)-induced hypothyroidism were reported. Case 1; a 73-year-old male, complaining of edema, was admitted to our hospital. He had been treated for his multi-drug-resistant pulmonary tuberculosis during the past 1 year with an antituberculous regimen consisting of ethambutol (EB), ethionamide (ETH) and PAS. A thyroid profile performed when he was admitted to our hospital showed several marked abnormalities: serum thyroid stimulating hormone (TSH) was elevated (69.4 microIU/ml: normal, 0.4-4.2 mIU/ml), free thyroxine level (T4) (0.01 ng/dl; normal, 0.70-1.60 ng/dl) and free triiodothyronine level (Ts) (0.60 pg/ml; normal, 2.3-4.1 pg/ml) were low. PAS was discontinued after he was admitted to our hospital, since PAS was believed to be the cause of the hypothyroidism. A thyroid profile that was repeated after the exclusion of PAS from treatment showed the following results: the TSH level was decreased (13.4 mIU/ml), the free T4 (0.93 ng/dl) were normal. During treatment with PAS, he had never received thyroid replacement therapy. Case 2; A 22-year-old female, complaining of hemosputum. She had been treated for her multi-drug-resistant pulmonary tuberculosis during the past 11 months with an antituberculous regimen consisting of EB, ETH and PAS. A thryoid profile performed when she was admitted to our hospital showed several marked abnormalities: elevated serum TSH (112.7 mIU/ml), and low T4 (2.0 micrograms/dl) and T3 (1.1 ng/ml). A thyroid profile that was repeated after the exclusion of PAS from treatment showed the following results: the TSH level was decreased (5.1 mIU/ml). Drug-induced hypothyroidism is an infrequent side effect of therapy with PAS, and only a few cases of PAS-induced hypothyroidism have been reported so far. In this report, we describe patients with hypothyroidism who were receiving therapy for multi-drug-resistant tuberculosis, tuberculosis namely, resistant to at least isoniazid (INH) and rifampicin (RFP), with a regimen that contained PAS.