Mucolytic — Cystic Fibrosis Pregnancy: There are no adequate and well-controlled studies in pregnant women. Animal reproduction studies in rats and rabbits showed no evidence of fetal harm at doses up to approximately 600 times the maximum recommended human dose. The background risk of major birth defects and miscarriage for the cystic fibrosis population is unknown.

Dornase Alfa (rhDNase)

Brand names: Pulmozyme

Dornase alfa is a recombinant human deoxyribonuclease (rhDNase) given by nebulisation as a mucolytic in cystic fibrosis.

Adult dose

Dose: 2.5 mg (one single-dose ampoule)

Route: Inhalation via a recommended jet nebuliser connected to an air compressor with adequate air flow and equipped with a mouthpiece or suitable face mask, or via a recommended vibrating mesh nebuliser

Frequency: Once daily; some patients may benefit from twice daily administration

SOURCE NOTE: no UK SPC (eMC) record was fetched in this bundle — this draft is from the US prescribing information for PULMOZYME (Genentech, label date 2025-12-17, https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=71192c41-f7be-44b0-b232-1f74369239a0). Verify against the UK SPC before use. INDICATION CONTEXT: the labelled dose is stated as the recommended dosage 'in most cystic fibrosis patients'. STRENGTH: inhalation solution 2.5 mg/2.5 mL (1 mg/mL), clear colourless solution in single-dose ampoules. NEBULISERS: no data are currently available to support administration with nebuliser systems other than those listed in the label. Recommended jet nebulisers (with the stated compressors) are the Hudson T Up-draft II, Marquest Acorn II, PARI LC Plus, PARI BABY and Durable Sidestream; recommended vibrating mesh nebulisers are the eRapid Nebulizer System, Innospire Go, Pulmogine Vibrating Mesh Nebulizer and AireHealth Nebulizer Intelligent Mesh Nebulizer. The eRapid Nebulizer System should only be used by adults and paediatric patients who can use a mouthpiece, and not by younger patients who need a mask; patients unable to inhale or exhale orally throughout the entire nebulisation period may use the PARI BABY nebuliser. HANDLING: squeeze each ampoule prior to use to check for leaks; discard if the solution is cloudy or discoloured; once opened, the entire contents of the ampoule must be used or discarded. Do not dilute or mix with other drugs in the nebuliser — mixing could lead to adverse physicochemical and/or functional changes. PAEDIATRIC (flat dose, not per-kg — so not expressed as a mg/kg dose): safety and effectiveness in conjunction with standard cystic fibrosis therapies have been established in paediatric patients. Use in patients 5 to 17 years is supported by a randomised placebo-controlled trial of 303 clinically stable cystic fibrosis patients aged 5 to 17 years; use in patients less than 5 years is supported by extrapolation of efficacy data in patients 5 years and older, with additional 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. Verify any under-18 use against a children's formulary. GERIATRIC: clinical studies did not include sufficient numbers of subjects aged 65 or older to determine whether they respond differently. WARNINGS: US label section 5 Warnings and Precautions reads 'None'.

Dose independently re-sourced from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. 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
Conjunctivitis, rhinitis, decrease in FVC of 10% or more, fever and dyspnoea (the above are the reactions occurring in 3% or more of treated patients over placebo)

Interactions

Available data indicate there are no clinically important drug-drug interactions
Do not dilute or mix with other drugs in the nebuliser — this could lead to adverse physicochemical and/or functional changes in dornase alfa or the admixed compound

Clinical monograph

How it works

It cleaves extracellular DNA released from degenerating neutrophils in purulent airway secretions, reducing sputum viscosity and improving mucus clearance.

Prescribing in practice

It is administered by jet nebuliser and must not be diluted or mixed with other nebuliser solutions.
Benefit is assessed over a sustained trial period as response in lung function and exacerbation frequency develops gradually.
Voice alteration, pharyngitis and conjunctivitis are recognised and usually transient adverse effects.

Monitoring

Monitor lung function and exacerbation frequency to assess ongoing benefit.

Counselling the patient

Use only with a recommended nebuliser device and do not mix it with other solutions in the chamber.
Store in the refrigerator and protect from light.
A temporary change in voice or sore throat may occur and usually settles.

Evidence & guidelines

Dornase alfa is established in cystic fibrosis management, with trials demonstrating improved lung function and reduced respiratory exacerbations.

Reference: Fuchs et al. NEJM 1994 (dornase alfa in CF); NICE TA117; SPC Pulmozyme; CF Trust Standards of Care; 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.

Calculators

Pathways