biostudies-literatureUnknown7(3)Ranganathan UDCDC<h4>Objectives</h4>To evaluate the effect of high-dose isoniazid in patients with isoniazid-resistant TB by its bactericidal activity after 1 or more weeks of treatment.<h4>Subjects and methods</h4>Using the rapid direct method of phenotypic drug susceptibility testing, we screened persons with positive sputum microscopy results and genotypic drug resistance for isoniazid resistance. Those with no growth at a critical concentration of 2.0 mg/L were invited to participate in a trial of high-dose isoniazid monotherapy lasting 6 days. After 3 days of no treatment, patients received isoniazid 15 mg/kg and were followed with serial quantitative sputum cultures from Days 0 to 6.<h4>Results</h4>We enrolled 15 patients after a median of 2 weeks standard first-line treatment. Their median bacillaryJAC-antimicrobial resistancedlaf072https://www.ebi.ac.uk/biostudies/studies/S-EPMC12096161biostudies-literatureHigh-dose isoniazid for TB with low-to-moderate isoniazid resistance after 1 week of treatment.PMC12096161Sridhar RNair DSwaminathan SEisenach KDRanganathan UDDevaleenal Daniel BRadhika GMaheswaran KLavanya JDevika KKumar SRaviKumar DMangalambal GBalaji SSrinivasan RBaskaran MSangamithirai DTripathy SSmith-Jeffcoat SECegielski JPfalseHigh-dose isoniazid for TB with low-to-moderate isoniazid resistance after 1 week of treatment.<h4>Objectives</h4>To evaluate the effect of high-dose isoniazid in patients with isoniazid-resistant TB by its bactericidal activity after 1 or more weeks of treatment.<h4>Subjects and methods</h4>Using the rapid direct method of phenotypic drug susceptibility testing, we screened persons with positive sputum microscopy results and genotypic drug resistance for isoniazid resistance. Those with no growth at a critical concentration of 2.0 mg/L were invited to participate in a trial of high-dose isoniazid monotherapy lasting 6 days. After 3 days of no treatment, patients received isoniazid 15 mg/kg and were followed with serial quantitative sputum cultures from Days 0 to 6.<h4>Results</h4>We enrolled 15 patients after a median of 2 weeks standard first-line treatment. Their median bacillary2025-01-01T00:00:00Z2025 Jun2026-06-03T02:43:07.225Z2026-04-23T03:11:41.47ZS-EPMC120961614040673610.1093/jacamr/dlaf072