High-Dose Isoniazid Lacks EARLY Bactericidal Activity against Isoniazid-resistant Tuberculosis Mediated by katG Mutations: A Randomized Phase II Clinical Trial.
Am J Respir Crit Care Med
; 210(3): 343-351, 2024 08 01.
Article
em En
| MEDLINE
| ID: mdl-38564365
ABSTRACT
Rationale Observational studies suggest that high-dose isoniazid may be efficacious in treating multidrug-resistant tuberculosis. However, its activity against Mycobacterium tuberculosis (M.tb) with katG mutations (which typically confer high-level resistance) is not established. Objectives:
To characterize the early bactericidal activity (EBA) of high-dose isoniazid in patients with tuberculosis caused by katG-mutated M.tb.Methods:
A5312 was a phase IIA randomized, open-label trial. Participants with tuberculosis caused by katG-mutated M.tb were randomized to receive 15 or 20 mg/kg isoniazid daily for 7 days. Daily sputum samples were collected for quantitative culture. Intensive pharmacokinetic sampling was performed on Day 6. Data were pooled across all A5312 participants for analysis (drug-sensitive, inhA-mutated, and katG-mutated M.tb). EBA was determined using nonlinear mixed-effects modeling. Measurements and MainResults:
Of 80 treated participants, 21 had katG-mutated M.tb. Isoniazid pharmacokinetics were best described by a two-compartment model with an effect of NAT2 acetylator phenotype on clearance. Model-derived maximum concentration and area under the concentration-time curve in the 15 and 20 mg/kg groups were 15.0 and 22.1 mg/L and 57.6 and 76.8 mg â h/L, respectively. Isoniazid bacterial kill was described using an effect compartment and a sigmoidal maximum efficacy relationship. Isoniazid potency against katG-mutated M.tb was approximately 10-fold lower than in inhA-mutated M.tb. The highest dose of 20 mg/kg did not demonstrate measurable EBA, except against a subset of slow NAT2 acetylators (who experienced the highest concentrations). There were no grade 3 or higher drug-related adverse events.Conclusions:
This study found negligible bactericidal activity of high-dose isoniazid (15-20 mg/kg) in the majority of participants with tuberculosis caused by katG-mutated M.tb. Clinical trial registered with www.clinicaltrials.gov (NCT01936831).Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
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Tuberculose Resistente a Múltiplos Medicamentos
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Isoniazida
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Mutação
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Mycobacterium tuberculosis
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Antituberculosos
Limite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Am J Respir Crit Care Med
Assunto da revista:
TERAPIA INTENSIVA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
África do Sul