N-Acetylcysteine (NAC)



N-Acetylcysteine or NAC for short is a drug primarily used to treat acetaminophen overdose. NAC functions to replenish glutathione levels, to prevent free radical injury by metabolites of acetaminophen. NAC is rarely used to liquefy mucus in individuals with cystic fibrosis or COPD.

Key Points

  • N-acetylcysteine (NAC)
    • Mechanism
      • Replenishes glutathione
        • Antioxidant that increases production of glutathione (GSH)
      • Breaks disulfide bonds in mucus
    • Indications
      • Acetaminophen-induced liver injury
        • Increased glutathione by NAC helps conjugate toxic NAPQI metabolites, reducing liver damage
      • Liquifies mucus (mucolytic) in lung
        • Used for obstructive airway diseases where mucous plugging plays a role (e.g. COPD, cystic fibrosis)
      • Prevention of radiocontrast nephropathy
        • Mechanism is unknown
    • Side Effects
      • GI upset (nausea/vomiting, constipation, diarrhea)