Development of Multidrug Resistance during Standardized Treatment in a Patient with Drug-Sensitive Tuberculosis / 대한내과학회지

ABSTRACT

Standard short-course chemotherapy (SSC) is recommended for new patients with pulmonary tuberculosis (TB). This approach has been regarded as among the most effective tools for preventing the development of resistance to anti-TB drugs. We report on the development of multidrug-resistance during SSC in a patient with drug-susceptible TB. Isoniazid, rifampin, pyrazinamide, and ethambutol were started, and negative culture conversion was obtained. Ethambutol was discontinued after 5 weeks of treatment due to visual dysfunction, and pyrazinamide was discontinued after a 2-month phase of intensive treatment. However, M. tuberculosis was cultivated from sputum collected after 9 weeks of treatment. Drug-susceptibility testing revealed resistance to isoniazid, rifampin, ethambutol, and rifabutin. Given that the patient took medication regularly, this observation suggests the possibility that some patients acquire drug resistance during SCC.