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Mucolytic / Antioxidant — COPD / Bronchiectasis

N-Acetylcysteine (Nebulised / Oral)

Brand names: Fluimucil, Parvolex (IV — different indication)

N-acetylcysteine is a mucolytic used in respiratory care, given orally or by nebuliser to reduce sputum viscosity in conditions with tenacious secretions. This entry covers its respiratory mucolytic use rather than its intravenous use in paracetamol overdose.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It splits disulphide bonds in mucus glycoproteins, lowering sputum viscosity and aiding clearance, and also contributes free thiol groups that act as an antioxidant.

Prescribing in practice

  • Nebulised N-acetylcysteine can provoke bronchospasm, so administer with bronchodilator cover and observe, particularly in asthma or hyperreactive airways.
  • Be ready for increased volume of liquefied secretions and ensure the patient can clear them, with suction available if cough is impaired.
  • It has a sulphurous odour and may be poorly tolerated; use a non-reactive nebuliser as directed.

Monitoring

Monitor respiratory status, secretion clearance and for wheeze or bronchospasm during and after nebulised administration.

Counselling the patient

  • The treatment loosens phlegm, so expect to cough more secretions up.
  • Tell staff if you feel wheezy or tight-chested during the nebuliser.
  • The medicine has a distinctive sulphur-like smell, which is expected.

Evidence & guidelines

Established practice and the SPC support N-acetylcysteine as a mucolytic to reduce secretion viscosity in selected respiratory conditions.

Reference: BRONCHUS Trial (Decramer et al. Lancet 2005); GOLD 2024; NICE NG115; SPC Fluimucil; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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