INFASURF PRESERVATIVE FREE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for INFASURF PRESERVATIVE FREE (INFASURF PRESERVATIVE FREE).
Infasurf (calfactant) is a natural bovine lung extract containing phospholipids (primarily dipalmitoylphosphatidylcholine, DPPC) and surfactant-associated proteins B and C. It reduces alveolar surface tension, preventing end-expiratory collapse and stabilizing alveoli, thereby improving lung compliance and gas exchange.
| Metabolism | Not metabolized; cleared from the lungs via alveolar macrophage uptake and degradation. |
| Excretion | Primarily cleared by alveolar macrophages and lung surfactant turnover; minimal renal or biliary excretion (<1%). |
| Half-life | Terminal half-life in preterm infants: 10-17 hours; clearance correlates with lung maturation and surfactant recycling. |
| Protein binding | Not significantly bound to plasma proteins; acts locally in alveoli. |
| Volume of Distribution | Apparent Vd: 0.3-0.6 L/kg (reflects distribution within lung fluid and surfactant pool; low due to local administration). |
| Bioavailability | Intratracheal: 100% (administered directly to airways); not applicable by other routes. |
| Onset of Action | Intratracheal: improved oxygenation within minutes; maximal effect on ventilation-perfusion matching by 15-30 minutes. |
| Duration of Action | Duration of respiratory improvement: 8-12 hours, with repeated dosing often needed (every 12 hours) based on clinical response. |
Not applicable; Infasurf Preservative Free is an intratracheal suspension indicated only for neonatal respiratory distress syndrome (RDS).
| Dosage form | SUSPENSION |
| Renal impairment | No dose adjustment required; drug is administered intratracheally and systemic absorption is negligible. |
| Liver impairment | No dose adjustment required; drug is administered intratracheally and systemic absorption is negligible. |
| Pediatric use | Neonates: 3 mL/kg birth weight (105 mg phospholipids/kg) intratracheally as a single dose; may repeat every 12 hours up to 3 total doses if still intubated and requiring FIO2 >0.30. |
| Geriatric use | Not indicated in geriatric population. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for INFASURF PRESERVATIVE FREE (INFASURF PRESERVATIVE FREE).
| Breastfeeding | Not indicated for use during lactation; no data on excretion in breast milk. M/P ratio not applicable. |
| Teratogenic Risk | No known teratogenic risk; animal studies show no fetal harm. Infasurf is administered intratracheally directly to neonates, not systemically during pregnancy. |
| Fetal Monitoring | Not applicable to maternal use; only administered to neonates. No maternal monitoring required. |
■ FDA Black Box Warning
None
| Common Effects | Application site reactions burning irritation itching and redness |
| Serious Effects |
["Hypersensitivity to bovine surfactant proteins or any component of the formulation."]
| Precautions | ["Rapid administration may cause airway obstruction, bradycardia, hypotension, or oxygen desaturation.","Transient episodes of bradycardia and decreased oxygen saturation have occurred during dosing.","Use only under direct supervision of clinicians experienced in neonatal resuscitation and airway management.","May require additional doses due to variable response."] |
| Food/Dietary | Not applicable. Infasurf is administered intratracheally and is not absorbed systemically. No food or drug interactions occur as it acts locally in the lungs. |
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| Fertility Effects | No data on fertility effects; not systemically absorbed, unlikely to impact fertility. |
| Clinical Pearls | Infasurf Preservative Free (calfactant) is a natural surfactant for intratracheal administration only. Administer via endotracheal tube into the distal trachea. Dosing is based on birth weight: 3 mL/kg (105 mg phospholipids/kg). Can repeat up to 3 doses every 12 hours. Monitor for transient hypoxia, bradycardia, and airway obstruction during administration. Pre-warm vial to room temperature and gently swirl (do not shake). Use within 4 hours of opening. Not for IV use. Rapid improvement in oxygenation (FiO2, a/A ratio) expected within minutes. |
| Patient Advice | Infasurf is given directly into the lungs through a breathing tube to treat breathing problems in premature infants. · Your baby will be monitored closely during and after the dose for any changes in heart rate or oxygen levels. · This medication helps the lungs stay open by replacing missing surfactant, which is needed for normal breathing. · Multiple doses may be given if breathing difficulties persist. · Do not stop or change the dose without consulting the neonatologist. · There are no food interactions as this medication is given via endotracheal tube. |