The Clinical Significance of the Emergence of Drug-Resistant Organisms during the Therapy of Chronic Pulmonary Tuberculosis with Hydrazides of Isonicotinic Acid

Abstract

SOON after the discovery of the potent antituberculosis effect of the isoniazid drugs in laboratory animals in 1951, a number of reports appeared describing their value in patients with pulmonary tuberculosis.^{1 , 2} Emergence of drug-resistant tubercle bacilli, or indication of such a phenomenon, was not reported in those studies although observations soon became available demonstrating that increased bacterial resistance to the drugs may appear rapidly during therapy with either isoniazid or iproniazid alone.^{3 4 5 6 7 8 9} The relative frequency and consistency of this phenomenon during isoniazid therapy have recently been confirmed by large and carefully controlled studies.^{10 11 12 13} However, uncertainty still exists regarding the clinical . . .