Calfactant - Dosage, Uses, Side Effects, and Contraindications

Introduction

Calfactant, a natural lung surfactant, was approved by the U.S. Food and Drug Administration (FDA) for clinical use on October 26, 1999. It is used to treat respiratory distress syndrome (RDS) in newborns. RDS is a condition that primarily affects premature infants, where the lungs do not produce enough surfactant, which helps keep the air sacs in the lungs open and prevents them from collapsing.

Calfactant belongs to a class of drugs known as pulmonary surfactants. It is derived from calf lung extract and contains various surfactant proteins and phospholipids similar to those found in human surfactants. When administered directly into the lungs, Calfactant helps to improve lung function and prevent or reduce the severity of respiratory complications associated with RDS.

Drug Group

Calfactant belongs to the drug group known as pulmonary surfactants. Pulmonary surfactants are substances that mimic the natural surfactant produced in the lungs. They help to reduce surface tension within the alveoli (air sacs) and keep them open, allowing for easier breathing and improved lung function.

Available Doses and Dosage Forms:

The specific doses of Calfactant for respiratory distress syndrome in newborns may vary based on several factors, including the infant's weight, gestational age, and the severity of their condition.

• Initial Dose: The initial dose of Calfactant is typically administered soon after birth or as soon as respiratory distress is identified. The recommended initial dose is often based on the infant's weight, typically 100 to 200 milligrams per kilogram (mg/kg). This initial dose may be administered as a single dose or divided into multiple smaller doses.

• Maintenance Doses: After the initial dose, additional doses of Calfactant may be given if necessary by the healthcare provider. Maintenance doses are usually administered at specified intervals, such as every 12, 24, or 48 hours, depending on the infant's response to treatment. Maintenance doses are often lower than the initial dose and can range from 25 to 100 mg/kg.

For Patients:

What Is Respiratory Distress Syndrome?

Respiratory distress syndrome (RDS) in newborns, also known as neonatal respiratory distress syndrome or infant respiratory distress syndrome, is a condition that primarily affects premature infants. It occurs when the infant's lungs are not fully developed and do not produce enough surfactant, which is a substance that helps keep the air sacs in the lungs open and prevents them from collapsing.

Causes:

RDS is most commonly caused by the immaturity of the infant's lungs, particularly in babies born before 37 weeks of gestation. Surfactant, essential for proper lung function, is typically produced in sufficient quantities after this gestational age. Premature infants often have insufficient surfactant levels, resulting in respiratory difficulties.

Symptoms:

The signs and symptoms of RDS may include:

• Rapid, shallow breathing, or difficulty breathing.

• Grunting sounds during breathing.

• Flaring of the nostrils.

• Bluish tint to the skin (cyanosis).

• Rapid heart rate.

• Retractions, where the chest appears to sink in with each breath.

• Decreased activity and lethargy.

Treatment:

The primary goal of treatment for RDS is to support the infant's breathing and oxygenation. Treatment options may include:

• Synthetic or animal-derived surfactant is administered directly into the baby's lungs to improve lung function and reduce respiratory complications.

• The infant may require mechanical ventilation, continuous positive airway pressure (CPAP), or other breathing support.

• Supplemental oxygen may be provided to maintain appropriate oxygen levels in the blood.

• Maintaining the infant's body temperature is crucial, often through incubators or warmers.

• Infants with RDS are usually cared for in neonatal intensive care units (NICUs), where they receive close monitoring and supportive care, including nutritional support and infection prevention.

How Does Calfactant Work?

Surfactant is a natural substance produced by the lungs. It is vital in reducing surface tension within the lungs' alveoli (air sacs). This allows the alveoli to remain open during exhalation and facilitates the exchange of oxygen and carbon dioxide. In newborns with RDS, especially premature infants, the lungs often have insufficient surfactant due to immaturity. The lack of surfactant increases surface tension within the alveoli, making it difficult for the lungs to expand properly during breathing. This leads to respiratory difficulties and compromised lung function. When administered directly into the lungs of newborns with RDS, Calfactant functions as an exogenous surfactant replacement. Calfactant helps to restore the deficient surfactant levels in the lungs.

How Effective Is Calfactant?

The effectiveness of Calfactant is demonstrated through various clinical studies and real-world experience. Here are some key points regarding the drug's effectiveness:

• Improved Respiratory Function: This drug improves the infant's respiratory function, allowing for more effective oxygenation and ventilation.

• Reduced Need for Mechanical Ventilation: Calfactant has been associated with reducing the need for mechanical ventilation in newborns with RDS. Mechanical ventilation is a supportive measure that assists with breathing but can also carry risks and complications.

• Decreased Incidence of Complications: Adequate treatment with Calfactant has been shown to reduce the incidence of certain complications associated with RDS. These may include complications such as pneumothorax (collapsed lung), bronchopulmonary dysplasia (a chronic lung disease), and other respiratory morbidities.

• Enhanced Survival Rates: Using Calfactant with appropriate respiratory support and neonatal intensive care has improved survival rates for infants with RDS. Early and effective administration of Calfactant can positively impact the outcomes and prognosis for newborns with respiratory distress syndrome.

What Are the Things to Inform the Doctor Before Taking the Calfactant?

Before taking a Calfactant or any medication, informing the doctor or healthcare provider about relevant medical information is important. Here are some important things to communicate to the doctor before starting Calfactant therapy for respiratory distress syndrome in newborns:

• Inform the doctor about known allergies or hypersensitivity reactions to Calfactant or other medications, including surfactant preparations or other substances. This includes allergies to animal-derived products, as Calfactant is derived from calf lung extract.

• Provide a comprehensive medical history of the newborn, including any preexisting conditions, past surgeries, or other relevant medical information.

• Disclose all the medications the newborn has recently taken, including prescription, over-the-counter, and supplements. Some medications can interact with Calfactant, potentially affecting their effectiveness or causing adverse effects.

• Inform the doctor if the newborn has a bleeding disorder or any condition that affects blood clotting. Calfactant can interfere with blood clotting; caution may be necessary.

• Notify the doctor if the newborn has any ongoing infections or if there is a suspicion of infection. Sometimes, it may be necessary to address the infection before initiating Calfactant therapy.

• Inform the doctor about additional respiratory conditions or complications, such as congenital abnormalities or lung diseases, as they may impact the treatment plan and potential response to Calfactant.

• Inform the doctor about any other medical conditions or significant health concerns the newborn has, as they may influence the overall management and use of Calfactant.

• If the mother is pregnant or breastfeeding, it is important to inform the doctor, as this information may have implications for administering Calfactant or other aspects of the treatment plan.

How Is Calfactant Administered?

Calfactant is administered directly into the lungs through a procedure called endotracheal intubation.

• Preparation: The healthcare provider will prepare the Calfactant for administration. Calfactant is usually supplied as a suspension, and the vial or pre-filled syringe containing the Calfactant suspension will be prepared according to the manufacturer's instructions.

• Endotracheal Intubation: The newborn will undergo endotracheal intubation, which involves the insertion of a small tube called an endotracheal tube into the trachea (windpipe) through the mouth or nose. This tube is an airway and delivers the Calfactant directly into the lungs.

• Positioning: The newborn will be appropriately positioned to facilitate administering and distributing the Calfactant within the lungs.

• Administration of Calfactant: The prepared Calfactant suspension is administered directly into the endotracheal tube. This is typically done using a syringe or specialized device.

• Ventilation and Assessment: After administering the Calfactant, the healthcare provider may briefly interrupt ventilation to allow the medication to spread evenly within the lungs. The provider will then resume mechanical ventilation or other respiratory support as needed. The infant's vital signs, oxygenation, and respiratory function will be monitored throughout the process.

What Are the Side Effects of Calfactant?

Serious Side Effects:

• Bradycardia: A slow heart rate.

• Desaturation: A decrease in blood oxygen levels.

• Cyanosis: Bluish discoloration seen in skin or mucous membranes due to low oxygen levels.

• Airway Obstruction: Blockage or narrowing of the airway passages.

• Apnea: Temporary cessation of breathing.

Common Side Effects:

• Reflux of Calfactant into the endotracheal tube, which may require suctioning.

• Temporary decreases in oxygen levels.

• Low blood pressure.

• Bleeding in the lungs.

Dietary Considerations

The dietary considerations for newborns with RDS may include the following:

• Parenteral Nutrition: In some cases, newborns with severe RDS may be unable to tolerate oral feedings initially. They may receive nutrition through intravenous methods, such as parenteral nutrition, which provides essential nutrients directly into the bloodstream.

• Breast Milk or Formula Feeding: Breast milk is often considered the optimal source of nutrition for newborns, as it provides essential nutrients and antibodies. If breastfeeding is not possible or insufficient, an appropriate infant formula may be used.

• Feeding Strategies: This may include techniques such as gradual advancement of feedings, smaller, more frequent feedings, or other modifications as advised by the healthcare team.

• Nutritional Support: The healthcare team will closely monitor the newborn's growth, nutritional status, and fluid balance. They may recommend additional nutritional supplements or adjustments to meet the infant's specific nutritional needs during their recovery from RDS.

Missed Dose

If a caregiver or parent of a newborn suspects that a dose of Calfactant has been missed. In that case, it is important to immediately inform the healthcare provider or nurse responsible for the newborn's care. They will assess the situation and determine the appropriate course of action.

In most cases, if a dose of Calfactant is missed, the healthcare team will administer it as soon as possible. They may adjust the following dosing schedule to ensure the newborn receives the necessary treatment. It is crucial to follow the healthcare provider's guidance and only attempt to administer the medication with proper training and authorization.

Overdose

In the case of an overdose or accidental excessive administration of Calfactant for treating respiratory distress syndrome (RDS) in newborns, it is important to seek immediate medical attention and contact the healthcare provider or emergency services. Symptoms or signs of a potential overdose or excessive administration of Calfactant may include respiratory distress, changes in heart rate, oxygen saturation, blood pressure, and other signs of medication-related complications.

Storage

• Calfactant should be stored at controlled room temperature, typically between 20 degrees Celsius to 25 degrees Celsius (68 degrees Fahrenheit to 77 degrees Fahrenheit).

• Avoid extreme heat or cold exposure, and do not freeze the medication.

• It Should be protected from direct sunlight or intense artificial light.

• Store it in its original packaging or container to shield it from light exposure.

• Take precautions to prevent contamination. Ensure that the vials or pre-filled syringes remain sealed until the time of use.

• Follow proper aseptic techniques during the administration process to maintain sterility.

• Follow the manufacturer's instructions regarding handling and storing it. Be mindful of any specific storage recommendations the manufacturer provides on the product label or packaging.

For Doctors:

What Are the Pharmacological Aspects of Calfactant?

Pharmacodynamics: Calfactant is a natural lung surfactant that reduces surface tension in the alveoli (tiny air sacs in the lungs) where gas exchange occurs. The surfactant components of Calfactant, such as phospholipids and proteins, form a thin layer on the surface of the alveoli. This layer lowers the surface tension and prevents the alveoli's collapse during expiration.

By reducing surface tension, Calfactant improves lung compliance, which refers to the ability of the lungs to expand and recoil. This leads to increased lung capacity and improved ventilation. Furthermore, Calfactant helps stabilize the alveoli, preventing their collapse at the end of expiration and maintaining their structural integrity. Restoring proper surfactant levels and improving lung compliance and alveolar stability facilitate efficient gas exchange in the lungs. Oxygen can enter the bloodstream more easily, while carbon dioxide is efficiently removed during expiration. Overall, the pharmacodynamic effects of Calfactant involve reducing surface tension, improving lung compliance, stabilizing alveoli, and promoting optimal gas exchange. These actions help alleviate respiratory distress, improve lung function, and enhance oxygenation in newborns with RDS.

Pharmacokinetics:

The pharmacokinetics of Calfactant, used for treating respiratory distress syndrome (RDS) in newborns, refers to how the medication is absorbed, distributed, metabolized, and eliminated in the body. Here are some key pharmacokinetic aspects:

• Administration: It is administered directly into the lungs through an endotracheal tube or other appropriate methods. It is instilled as a liquid suspension, which spreads over the alveolar surface.

• Absorption: It spreads and coats the alveoli once administered into the lungs. The surfactant components of Calfactant interact with the lung tissue to provide the necessary surfactant replacement.

• Distribution: It remains localized within the lungs after administration. It forms a thin layer on the alveolar surface, reducing surface tension and improving lung function.

• Metabolism: It is not metabolized in the body. It acts locally within the lungs to restore the deficient surfactant and improve respiratory function.

• Elimination: Since Calfactant remains within the lungs, it is not extensively eliminated from the body. Over time, the natural clearance mechanisms in the lungs, such as mucociliary clearance and alveolar macrophage activity, may contribute to removing Calfactant from the alveolar surface.

Toxicity:

Calfactant is generally well-tolerated with a low risk of toxicity. Since it is administered directly into the lungs of newborns with respiratory distress syndrome (RDS), the systemic absorption of Calfactant is minimal, limiting the potential for systemic side effects or toxicity. However, as with any medication, adverse reactions or complications are possible. Some potential considerations regarding Calfactant use include:

• Pulmonary Complications: In rare cases, administering Calfactant may cause transient adverse events related to the respiratory system. These can include bradycardia (slow heart rate), desaturation (low oxygen levels), airway obstruction, and transient episodes of decreased oxygenation. These events are typically transient and resolved with supportive care.

• Infection Risk: The Calfactant administration requires proper aseptic technique to minimize the risk of infection. However, as with any invasive procedure, there is a small risk of infection associated with the administration process.

• Allergic Reactions: Although rare, hypersensitivity and allergic reactions have been reported using Calfactant.

What Are the Contraindications of Calfactant?

Here are some common contraindications associated with Calfactant:

• Calfactant should not be administered to individuals with known hypersensitivity or allergic reactions to Calfactant or its components. Hypersensitivity reactions can range from mild allergic reactions to severe anaphylaxis.

• Calfactant is specifically indicated for treating respiratory distress syndrome (RDS) in newborns. It is not intended for use in individuals with ARDS, a different respiratory condition typically affecting adults and characterized by lung inflammation and injury.

• Suppose the newborn has an active infection or sepsis. In that case, the administration of Calfactant may need to be delayed or avoided due to the potential risk of exacerbating the infection or complicating the sepsis management.

• If the newborn has a bleeding disorder or is at risk of bleeding complications, caution should be exercised when administering Calfactant to minimize the risk of bleeding.

Drug Interaction:

Here are some general considerations regarding drug interactions:

• Other Respiratory Medications: When administering Calfactant, caution should be exercised if other respiratory medications or treatments are used concurrently. It is important to consult with healthcare professionals to ensure compatibility and avoid potential interactions.

• Antibiotics or Antifungals: If the newborn receives antibiotics or antifungal medications, it is important to consider potential interactions with Calfactant. Certain antibiotics or antifungal agents may affect the efficacy or stability of the Calfactant, and adjustments in timing or administration may be necessary.

• Blood Thinners: Calfactant does not have direct interactions with blood thinners. However, suppose the newborn is on blood-thinning medications, such as Heparin or Warfarin. In that case, healthcare professionals should be informed to monitor for potential bleeding complications during or after Calfactant administration.

Warnings and Precautions:

• Administration by Healthcare Professionals: Calfactants should be administered by healthcare professionals experienced in neonatal resuscitation and skilled in the placement and management of an endotracheal tube.

• Pulmonary Hemorrhage: Calfactant administration may rarely cause pulmonary hemorrhage (lung bleeding). Precautions should be taken to minimize the risk, especially in newborns with a history of bleeding disorders or those at risk of bleeding complications.

• Monitoring and Resuscitation Equipment: Adequate monitoring and resuscitation equipment should be readily available during and after Calfactant administration. This ensures prompt intervention in case of any adverse events or complications.

• Hypersensitivity Reactions: Hypersensitivity reactions, including anaphylaxis, have been reported with Calfactant. Healthcare professionals should be vigilant for any signs of allergic reactions during or following administration.

• Infection Control: Appropriate infection control measures should be followed during the preparation and administration of Calfactant to reduce the risk of infection.