n-acetylcysteine increases glutathione N-Acetyl-Cysteine supplementation lowers high homocysteine plasma levels and synthesis in the trans-sulfuration pathway: Beneficial effects on several cardiovascular and neurodegenerative diseases Chemical formula of N-acetylcysteine and

Secondary endpoints Secondary endpoints include the following: Time to 10% relative decline in FVC% predicted, first respiratory hospitalization, lung transplantation, or death from any cause Time to death from any cause Time to first respiratory hospitalization Time to 10% relative decline in FVC Time to lung transplantation Time to 10% relative decline in FVC% predicted Time to first all-cause hospitalization Annualized rate of respiratory hospitalizations Annualized rate of non-elective, all-cause hospitalizations Proportion of participants undergoing lung transplantation during follow-up Change in FVC % predicted from randomization to 12 and 24 months Change in FVC from randomization to 12 and 24 months Change in DLCO uncorrected, from randomization to 12 and 24 months Change in patient-reported outcomes scores from randomization to 12 and 24 months (Leicester Cough Questionnaire, EuroQoL EQ-5D, UCSD-SOB, K-BILD, SGRQ scores) Proportion of participants with and number of treatment- emergent adverse events, serious adverse events, adverse events leading to discontinuation, unanticipated problems Exploratory endpoints Exploratory endpoints are related to home spirometry and include the following: Time to 10% relative decline in home spirometry FVC Time to 10% relative decline in home spirometry FVC % predicted Change in home spirometry FVC % predicted from randomization to 12 and 24 months Change in home spirometry FVC from randomization to 12 and 24 months Comparison between a 10% relative decline captured by home spirometry with the relative change in FVC captured by the next on-site FVC measurement Data and safety monitoring board Safety and oversight will be under the direction of a Data and Safety Monitoring Board (DSMB) that is appointed by the NHLBI

Koskenkorva-Frank TS, Weiss G, Koppenol WH, Burckhardt S (2013) The complex interplay of iron metabolism, reactive oxygen species, and reactive nitrogen species: insights into the potential of various iron therapies to induce oxidative and nitrosative stress

4 Source Data Extended Data Fig

Jill Enfield, CT Leah was great

Runny nose: Excess mucus production or a runny nose may occur in response to the spray