Palivizumab (Synagis) is a monoclonal antibody used for the prophylaxis of RSV (Respiratory Syncytial Virus) infection.

• Palivizumab (Synagis) use in the prophylaxis of Respiratory syncytial virus prophylaxis:

  •  In pediatric patients with a history of premature birth (≤35 weeks gestational age) and who are ≤6 months at the beginning of RSV season, prevention of serious lower respiratory tract disease caused by a respiratory syncytial virus (RSV).
  • Pediatric patients with bronchopulmonary dysplasia (BPD) that required medical evaluation & treatment within the previous 6 months & who are ≤24 months at the beginning of RSV season; or pediatric patients with hemodynamically significant congenital heart disease (CHD) & who are ≤24 months at the beginning of RSV season.

  • During RSV season, The American Academy of Pediatrics (AAP 2014) recommends RSV prophylaxis with palivizumab for:

    • Infants born at ≤28 weeks six days gestational age & <12 months at the start of RSV season
    • Infants <12 months of age with chronic lung disease (CLD) of prematurity
    • Infants ≤12 months of age with hemodynamically significant CHD
    • Infants and children <24 months of age with CLD of prematurity necessitating medical therapy (eg, supplemental oxygen, bronchodilator, diuretic, or chronic steroid therapy) within six months prior to the beginning of RSV season

  • AAP also suggests that palivizumab prophylaxis may be contemplated in the following circumstances:

    • Infants <12 months of age with congenital airway abnormality or neuromuscular disorder that decreases the ability to control airway secretions
    • Infants <12 months of age with cystic fibrosis with clinical evidence of CLD and/or nutritional compromise
    • Children <24 months with cystic fibrosis with severe lung disease (the previous hospitalization for pulmonary exacerbation in the first year of life or abnormalities on chest radiography or chest computed tomography that persists when stable) or weight for length less than the 10th percentile
    • Infants and children <24 months who are profoundly immunocompromised
    • During RSV season, infants and children <24 months undergoing cardiac transplantation

  • Limitations of use:

    • For the treatment of RSV disease, Safety and efficacy have not been established.

Palivizumab (Synagis) Dose in Adults

Not indicated in adults.

Palivizumab (Synagis) Dose in Children

Palivizumab (Synagis) Dose in the prevention of RSV:

• Infants and Children <24 months:

  • IM:

    • Throughout RSV season, 15 milligram/kilogram once monthly.
    • Prior to the commencement of RSV season, the first dose administered.

  • Note:

    • AAP recommends max 5 doses per season.
    • Monthly prophylaxis should be discontinued for the remainder of that season if hospitalization occurs for breakthrough RSV infection. (AAP, 2014).

Palivizumab (Synagis) Dose in the treatment of Cardiopulmonary bypass patients:

• Even if <1 month from the previous dose, administer a 15 milligram/kilogram dose as soon as possible after cardiopulmonary bypass procedure or at the conclusion of extracorporeal membrane oxygenation.
• After cardiopulmonary bypass, a 58 percent decrease in palivizumab serum concentrations has been noted.

Palivizumab (Synagis) Dose in the treatment of RSV, treatment in patients at high-risk for severe disease:

• Limited data available:

• Infants, Children, and Adolescents:

  • IV:

  • 15 milligram/kilogram as a single dose.
  • Used in combination with ribavirin therapy, in most patients.
  • In 2 patients with disease progression, a single repeat dose at 3-5 days after the initial dose was reported.
  • Dosing based on experience in 85 patients the majority of which are pediatric patients & mostly ≤2 years of age.

Not for adults use.

Palivizumab (Synagis) Dose in Children:

• Infants and Children <24 months:

  • In the manufacturer's labeling, there are no dosage adjustments provided.

Palivizumab (Synagis) Dose in Liver Disease:

• Infants and Children <24 months:

  • In the manufacturer's labeling, there are no dosage adjustments provided.

Common Side Effects of Palivizumab (Synagis):

• Dermatologic:

  • Skin rash

• Miscellaneous:

  • Fever

Less Common Side Effects of Palivizumab (Synagis):

• Immunologic:

  • Antibody development

Contraindications to Palivizumab (Synagis):

• Previous hypersensitivity reactions to palivizumab and any component of the formulation.

• Canadian labeling:

  • Hypersensitivity to humanized monoclonal antibodies

Warnings and precautions

• Anaphylactoid reactions and hypersensitivity reactions

  • Some fatalities have been reported after anaphylactic shock and Anaphylaxis following initial or re-exposure.
  • Other severe hypersensitivity reactions have been reported.
  • If a severe hypersensitivity reaction occurs, discontinue treatment.
  • If anaphylaxis occurs or any other serious hypersensitivity reaction, administer appropriate medication (e.g. epinephrine) as well as provide support care.
  • If mild hypersensitivity occurs, it is important to use clinical judgment when deciding whether to re-administer the medication.

• Bleeding disorders:

  • Patients with bleeding disorders, including thrombocytopenia, should be cautious.
  • Bleeding/hematoma can occur after intramuscular injections.

Monitoring Parameters:

Monitor for anaphylaxis or acute hypersensitivity reactions.

How to administer Palivizumab (Synagis)?

IM:

• Preferably in the anterolateral aspect of the thigh, administer undiluted solution IM.
• Because of the risk of damage to the sciatic nerve, the gluteal muscle should not be used routinely as an injection site.
• As a divided dose, injection volume over 1 mL should be given.
• Do not dilute the product.
• Do not shake or vigorously agitate the vial.

IV:

• In pediatric patients, in clinical trials ≤2 years, palivizumab has been administered IVP over 2-5 minutes or IV infusion through a 0.2 micron filter at a rate not to exceed 1-2 mL per minute at a final concentration of 10-20 milligram per mL.

Mechanism of action of Palivizumab (Synagis):

• RSV is neutralizing and fusion inhibitory.
• These activities are used to stop RSV replication in clinical and laboratory studies.

Bioavailability:

• Infants and Children <24 months without CHD: 70%

Half-life elimination:

• Infants and Children <24 months without CHD:  Twenty days
• Clearance:
• Infants and Children <24 months of age without CHD: ~11 mL per day

International Brands of Palivizumab:

• Synagis
• Abbosynagis

Palivizumab Brand Names in Pakistan:

No Brands Available in Pakistan.