About pyrazinamideniacinamide derivative, antitubercular.mechanism of action of pyrazinamidepyrazinamide is a bactericidal or bacteriostatic drug depending on the drug concentration at the infection site and the susceptibility of organism. pyrazinamide is a prodrug and it undergoes hydrolysis and forms the active metabolite pyrazinoic acid. it disrupted membrane energetic and inhibited membrane transport function at acid ph in mycobacterium tuberculosis. the anti-mycobacterial activity appears to depend on conversion of the drug to pyrazinoic acid. susceptible strains of m. tuberculosis produce pyrazinamidase, an enzyme that deaminates pyrazinamide to pyrazinoic acid, and the vitro susceptibility of a given strain of the organism appears to correspond to its pyrazinamidase activity. experimental evidence suggests that pyrazinamide diffuses into m. tuberculosis in a passive manner, is converted into pyrazinoic acid by pyrazinamidase and because of an inefficient efflux system