Mucolytic (recombinant DNase enzyme) Pregnancy: There are no adequate and well-controlled studies in pregnant women. In animal reproduction studies in rats and rabbits no evidence of fetal harm was observed at doses up to approximately 600 times the maximum recommended human dose.

Dornase alfa (recombinant human DNase)

Brand names: Pulmozyme

Dornase alfa is a nebulised recombinant human deoxyribonuclease used to improve mucociliary clearance and lung function in cystic fibrosis. It is given by inhalation via an appropriate nebuliser, usually once daily.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 2.5 mg (one single-dose ampule; 2.5 mg/2.5 mL, 1 mg/mL)

Route: Inhalation, via a recommended jet nebuliser connected to an air compressor system (e.g. Hudson T Up-draft II, Marquest Acorn II, PARI LC Plus, PARI BABY, Durable Sidestream) or via a vibrating mesh nebuliser (e.g. eRapid Nebulizer System, Innospire Go, Pulmogine, AireHealth, Intelligent Mesh)

Frequency: Once daily in most cystic fibrosis patients; some patients may benefit from twice daily administration

Paediatric use is established: use in patients 5 to 17 years is supported by a randomised placebo-controlled trial in 303 clinically stable CF patients; use in patients under 5 years is supported by extrapolation of efficacy data from patients 5 years and older together with safety data in 65 paediatric patients aged 3 months to less than 5 years who received 2.5 mg daily by inhalation for 2 weeks — i.e. the label describes the same fixed 2.5 mg once-daily dose, not a per-kilogram dose. Squeeze each ampule before use to check for leaks; discard if the solution is cloudy or discoloured; once opened the entire contents must be used or discarded. Do not dilute or mix with other drugs in the nebuliser. The eRapid Nebulizer System should only be used by adults and paediatric patients who can use a mouthpiece, not by younger patients who need a mask. The Warnings and Precautions section of this label states 'None.' No UK SPC (eMC) record was retrieved in this bundle — the dose above is from US prescribing information (Pulmozyme) and must be verified against UK labelling.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to dornase alfa, Chinese Hamster Ovary cell products, or any component of the product

Side effects

Voice alteration
Pharyngitis and laryngitis
Rash
Chest pain and dyspnoea
Conjunctivitis, rhinitis, fever and a decrease in FVC of 10% or more

Interactions

Available data indicate there are no clinically important drug-drug interactions with dornase alfa

Clinical monograph

How it works

It cleaves the extracellular DNA released from degraded neutrophils that accumulates in purulent cystic fibrosis sputum, markedly reducing its viscosity. Thinner secretions are easier to expectorate.

Prescribing in practice

It must only be given by inhalation through a recommended nebuliser and must never be diluted or mixed with other solutions in the chamber, to preserve activity and avoid contamination.
Voice changes (hoarseness), pharyngitis, and transient lung-function dips can occur but rarely require discontinuation.
It is not interchangeable with oral mucolytics and is reserved for cystic fibrosis.

Monitoring

Monitor lung function and symptomatic response, and review correct nebuliser use and device maintenance.

Counselling the patient

Use only your recommended nebuliser and do not mix it with any other medicine.
A temporary hoarse voice or sore throat may occur and usually settles.
Clean and maintain the nebuliser regularly to keep it working properly.

Evidence & guidelines

Dornase alfa is established in UK cystic fibrosis care for improving lung function and reducing exacerbations as part of airway clearance.

Reference: SmPC Pulmozyme; CF Trust Standards of Care 2024; Fuchs et al. NEJM 1994; 331:637; NICE NG78 (CF management); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Pathways