Ethionamide is a second-line antitubercular drug primarily used in the treatment of multidrug-resistant tuberculosis. It belongs to the thioamide class of antimycobacterial agents and is effective against Mycobacterium tuberculosis. The drug plays an important role when first-line antitubercular medications fail due to resistance. Ethionamide works by inhibiting the synthesis of mycolic acids, which are essential components of the mycobacterial cell wall. By disrupting cell wall formation, it weakens the bacteria and leads to their destruction. Its mechanism of action is similar to that of isoniazid, although it is used mainly as an alternative agent .The drug was developed in the 1950s during efforts to discover new treatments for tuberculosis. It was introduced into clinical practice as drug-resistant strains of tuberculosis began to emerge. Over time, Ethionamide became an important part of combination therapy regimens for managing resistant tuberculosis cases.
