Used primarily in the treatment of tuberculosis, especially multidrug-resistant tuberculosis (MDR-TB). It is part of second-line antituberculosis therapy when first-line drugs are ineffective or not tolerated. Prothionamide works by inhibiting mycolic acid synthesis in the bacterial cell wall, thereby disrupting the structural integrity of Mycobacterium tuberculosis. It is typically administered in combination with other antitubercular agents to prevent the development of resistance. Due to its potential for hepatotoxicity and other side effects, regular monitoring is required during treatment. Its use may also extend to treating certain nontuberculous mycobacterial infections under specific clinical circumstances.