Learning Center/Pharmacology/Dornase Alfa

Dornase Alfa

Pulmozyme

mucolyticinhaled (SVN)Onset: Days to weeks for significant mucociliary clearance improvementDuration: Sustained with daily use

Mechanism of Action

Recombinant human DNase I enzyme. Cleaves extracellular DNA (from neutrophil breakdown) that contributes to the viscosity of CF sputum. Reduces sputum viscoelasticity without affecting mucin or disulfide bonds.

Dosing

Adult

SVN: 2.5 mg (1 ampule) once daily via recommended nebulizer systems

Pediatric

≥5 years: 2.5 mg once daily. Some patients may benefit from BID dosing

Indications

Cystic fibrosis (management of thick secretions)
May be used in non-CF bronchiectasis (off-label)

Contraindications

Hypersensitivity to dornase alfa or Chinese Hamster Ovary cell products

Side Effects

Voice alteration (most common)
Pharyngitis
Laryngitis
Rash
Chest pain
Rhinitis

Monitoring Parameters

FEV1 and spirometry
Frequency of CF exacerbations
Voice changes

Drug Interactions

No significant drug interactions

Clinical Pearls

Specific to CF — targets extracellular DNA (not mucin like acetylcysteine)
Must use recommended nebulizer systems: PARI LC Plus or Hudson T Up-Draft II
Store in refrigerator (2–8°C); protect from light
Administer after airway clearance techniques for best results
Reduces CF pulmonary exacerbations by ~22%
Not effective in non-CF asthma or COPD

Mnemonic

💡 Pulmozyme Pulverizes DNA (extracellular) in CF mucus

NBRC High-Yield

Specific to cystic fibrosis — cleaves extracellular DNA in sputum
Distinct mechanism from acetylcysteine (cleaves disulfide bonds)
2.5 mg SVN once daily; requires specific nebulizer systems
Does not cause bronchospasm (unlike acetylcysteine)
Store refrigerated; protect from light

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