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Mucolytic — Cystic Fibrosis Pregnancy: Limited data — use only if clearly indicated; CF in pregnancy requires specialist multidisciplinary input

Dornase Alfa (rhDNase)

Brand names: Pulmozyme

Adult dose

Dose: 2.5 mg once daily (nebulised)
Route: Nebulised (jet nebuliser — specific compatible models only; not ultrasonic)
Frequency: Once daily (some patients benefit from twice daily)
Max: 2.5 mg twice daily
Recombinant human DNase — cleaves extracellular DNA in CF sputum (from neutrophil breakdown) reducing viscosity. Improves mucociliary clearance and reduces exacerbations. Must be used with compatible jet nebuliser (Pari LC Plus, VENTSTREAM). Administer after physiotherapy.

Paediatric dose

Dose: 2.5 mg once daily mg/kg
Route: Nebulised
Frequency: Once daily
Max: 2.5 mg twice daily
BNFc: licensed from 5 years of age. Same dose as adults. Physiotherapy before nebulisation enhances efficacy.

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Paediatric weight-based calculator

BNFc: licensed from 5 years of age. Same dose as adults. Physiotherapy before nebulisation enhances efficacy.

Clinical pearls

  • Reduces sputum viscosity by cleaving extracellular DNA released from neutrophils — highly concentrated in CF sputum; DNA increases viscosity 600-fold
  • Administer AFTER chest physiotherapy — loosened mucus can then be cleared by dornase-mediated viscosity reduction
  • Compatible nebuliser essential: Pari LC Plus or VENTSTREAM — ultrasonic nebulisers and some jet nebulisers inactivate dornase alfa; always check compatibility
  • Store in refrigerator (2–8°C) — do not expose to room temperature for extended periods; protect from light
  • NICE recommends dornase alfa for CF patients ≥5 years with FVC >40% predicted — strong evidence for reducing exacerbations and improving FEV1
  • Now used in combination with CFTR modulators (Kaftrio) — complementary mechanisms; mucus clearance benefit remains even with improved CFTR function

Contraindications

  • Hypersensitivity to dornase alfa or Chinese hamster ovary cell products

Side effects

  • Pharyngitis
  • Voice alteration/hoarseness
  • Laryngitis
  • Chest pain
  • Dyspnoea
  • Rash (rare)
  • Conjunctivitis

Interactions

  • No clinically significant drug interactions

Monitoring

  • FEV1 / FVC (spirometry) every 3 months
  • Exacerbation frequency
  • Sputum microbiology
  • Nebuliser device maintenance

Reference: BNFc; BNF 90; BNFc; Fuchs et al. NEJM 1994 (dornase alfa in CF); NICE TA117; SPC Pulmozyme; CF Trust Standards of Care. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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