ABSTRACT
Isoniazid, isonicotinic acid hydrazide (INAH or INH), was discovered independently in 1952 at both Squibb and Roche Laboratories (Bernstein et al., 1952; Fox, 1953). Animal studies showed that isoniazid was a very potent antituberculosis drug, and subsequent clinical trials confirmed its high efficacy for the treatment of human tuberculosis (An Interim Report, 1952). Isoniazid inhibits mycolic acid synthesis and has potent early bactericidal activity against Mycobacterium tuberculosis. It is relatively nontoxic, inexpensive, and remains an important first-line drug for the treatment of tuberculosis.
