Clinical efficacy, safety evaluation, and mechanism of acetylcysteine in improving first-line anti-tuberculosis treatment of newly diagnosed pulmonary TB: an open-label, randomized, single-center trial

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• Picked for Pulmonary and Respiratory Medicine (top studies of the week, 25 October 2026): Adjunctive N‑acetylcysteine improves TB treatment outcomes

Abstract

OBJECTIVE: To investigate the clinical efficacy, safety and mechanism of N-acetylcysteine combined with conventional antituberculosis drugs in the treatment of newly diagnosed pulmonary tuberculosis. METHODS: A total of 90 newly diagnosed pulmonary tuberculosis patients were randomly assigned to a Control group (n = 30), Aerosol NAC group (n = 30), or Oral NAC group (n = 30). The Control group received standard HRZE therapy, whereas the Aerosol NAC and Oral NAC groups received additional nebulized N-acetylcysteine (300 mg twice daily) or oral N-acetylcysteine (600 mg once daily), respectively. Clinical efficacy, sputum conversion, St. George's Respiratory Questionnaire (SGRQ) scores, liver function indices, oxidative stress biomarkers, inflammatory markers, and adverse events were assessed over 3 months. Data were analyzed using one-way ANOVA, repeated-measures ANOVA, Chi-square tests, and Bonferroni-adjusted post hoc analyses. RESULTS: Treatment successful response rates were significantly higher in the Aerosol NAC group (96.67%) and Oral NAC group (93.33%) than in the Control group (70.00%) (p < 0.05). At 3 months, sputum conversion rates reached 93.33 and 96.67% in the Aerosol NAC and Oral NAC groups, respectively, compared with 73.33% in the Control group (p < 0.05). Both NAC groups demonstrated significantly lower SGRQ scores, improved liver function parameters (AST, ALT, TBIL, and GGT), higher antioxidant enzyme levels (SOD and GSH-Px), lower MDA concentrations, and reduced inflammatory markers (IFN-γ, PCT, and IL-4) compared with the Control group (all p < 0.05). The incidence of adverse reactions was lower in both NAC groups (10.0%) than in the Control group (40.0%) (p < 0.05). CONCLUSION: Adjunctive N-acetylcysteine, administered either by aerosol inhalation or orally, significantly improved treatment outcomes, accelerated sputum conversion, reduced oxidative stress and inflammation, protected liver function, and decreased adverse events in patients with newly diagnosed pulmonary tuberculosis.

Abstract as published, via PubMed.