Isoniazid
antibiotic for treatment of tuberculosis
Isoniazid, also known as isonicotinic acid hydrazide (INH), is an antibiotic used for the treatment of tuberculosis. For active tuberculosis, it is often used together with rifampicin, pyrazinamide, and either streptomycin or ethambutol. It may also be used for atypical types of mycobacteria, such as M. avium, M. kansasii, and M. xenopi. It is usually taken by mouth, but may be used by injection into muscle.
Isoniazid is a prodrug that, when activated by catalase-peroxidase KatG, generates adducts and radicals that inhibit the formation of the mycobacterial cell wall. Side effects in those treated with isoniazid include vitamin B6 deficiency, liver toxicity, peripheral neuropathy, and a reduction in blood cell production. Mutations in the ahpC, inhA, kasA, katG, genes of M. tuberculosis may result in isoniazid resistance.
Although first synthesized in 1912, the anti-tuberculosis activity of isoniazid was not discovered until the 1940s. It is on the World Health Organization's List of Essential Medicines and is available as a generic medication.
Medical uses
Tuberculosis
The primary use of isoniazid is as first-line treatment for latent and active infection of Mycobacterium tuberculosis, the causative agent of tuberculosis (TB).
The public source identifies “Isoniazid” as antibiotic for treatment of tuberculosis. This brief keeps that definition visible, then builds a research path around Isoniazid, antibiotic and treatment.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 5, 2026. The linked authority identifier is Q423169. The Library of Congress control number is sh87001831. None of the 1 selected statements returned an explicit reference. The first chronological checks are 1912.
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This entry incorporates text from “Isoniazid” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.