N-acetylcysteine and mortality in hospitalized pulmonary tuberculosis infection

<b>Background:</b> N-Acetylcysteine (NAC) is associated with antimycobacterial activity in pulmonary tuberculosis (PTB). However, no study has shown the association between NAC and mortality in a hospitalized patient with PTB. <b>Methods:</b> A retrospective cohort study was conducted by reviewing all hospitalized PTB infection medical records from January 2013 to June 2018 at Khon Kaen Hospital, Thailand. The exposure of our interest was NAC regardless of doses and durations. Our primary outcome was 90-day all-cause mortality after admission and the secondary outcomes were cardiac arrest, acute respiratory failure (ARF) after admission, duration of ventilator use and duration of intensive care unit (ICU) stay. <b>Results:</b> There were 4,698 patients in our study period, 472 exposed to NAC and 4,226 did not expose to NAC during admission. We found that NAC was significantly associated with a reduction of 90-day all-cause mortality (adjusted hazard ratio (AHR), 0.74; 95% CI, 0.65 to 0.83). For the secondary outcomes, we found that NAC was significantly associated with increased duration of ventilator use (relative risk (RR), 1.02; 95% CI, 1.01 to 1.03), but cardiac arrest (adjusted relative risk, 0.69; 95% CI, 0.43 to 1.12), ARF after admission (AHR, 0.85; 95% CI, 0.66 to 1.09), duration of ICU stay (RR, 1.01; 95% CI, 0.99 to 1.03) were not significantly different between the two groups. <b>Conclusion:</b> NAC was significantly associated with a reduction of all-cause mortality within 90 days after admission in patients with PTB.