ethionamide

Ethionamide is a small molecule antibiotic used as a second-line agent for the treatment of active tuberculosis (TB), particularly in cases resistant to first-line drugs such as isoniazid or rifampin. It is also rarely used against infections with Mycobacterium leprae and other nontuberculous mycobacteria. Ethionamide acts as a prodrug that requires activation by the mycobacterial enzyme EthA; once activated it forms an adduct with NAD+ and inhibits InhA (enoyl-acyl carrier protein reductase), thereby disrupting the synthesis of mycolic acids—essential components of the bacterial cell wall. This mechanism is similar to that of isoniazid but involves distinct activation pathways. Ethionamide may be bacteriostatic or bactericidal depending on drug concentration and organism susceptibility[3][5][6]. It must be administered in combination with other antituberculosis agents due to rapid development of resistance when used alone[1][2].

Brand names

TrecatorTrecator-SC

Other names

ethionamide13142-ethylisothionicotinamideamidazinethioamideiridocin