Generic & Brand Names
Generic: Acetylcysteine (N-Acetylcysteine, NAC)
Common Brands: Fluimucil®, Mucomyst®, NAC®
Drug Class
Mucolytic Antioxidant Antidote Mechanism of Action
Acetylcysteine breaks disulfide bonds in mucoproteins, reducing mucus viscosity and facilitating expectoration. It replenishes intracellular glutathione stores, providing antioxidant effects. It acts as an antidote in paracetamol (acetaminophen) poisoning by detoxifying toxic metabolites.
Indications
- Productive cough with thick sputum
- Acute and chronic bronchitis
- Chronic obstructive pulmonary disease (COPD)
- Bronchiectasis
- Paracetamol (acetaminophen) overdose
- Cystic fibrosis (adjunct)
Dosage (General)
- Oral (mucolytic): 200 mg 2–3 times daily (adults)
- Children: 10–15 mg/kg/day in divided doses
- Paracetamol poisoning: As per standard NAC protocol
Ensure adequate hydration.
Side Effects
- Nausea
- Vomiting
- Diarrhea
- Bronchospasm (rare, inhalation)
- Rash, urticaria
- Anaphylactoid reactions (IV use)
Contraindications & Precautions
- Hypersensitivity to acetylcysteine
- Asthma (use with caution)
- Peptic ulcer disease
Drug Interactions
- Activated charcoal may reduce oral NAC absorption
- No significant interaction with bronchodilators
Pregnancy & Lactation
Considered safe when clinically indicated. Use only if benefits outweigh potential risks.
Key Notes
- Effective antidote for paracetamol poisoning
- Unpleasant sulfur odor common
- Do not combine routinely with antitussives
References
- British National Formulary (BNF). Mucolytics – Acetylcysteine.
- British National Formulary for Children (BNFc). Expectorants and mucolytics.
- Kliegman RM, St. Geme JW. Nelson Textbook of Pediatrics, 22nd ed. Elsevier.
- Katzung BG, Trevor AJ. Basic & Clinical Pharmacology, 15th ed. McGraw-Hill.