Nirsevimab

Nirsevimab is a prescription medication indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants born during or entering their first RSV season and in children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.

• Nirsevimab is available under the following different brand names: Beyfortus, Nirsevimab-alip

Common side effects of Nirsevimab include:

• none

Serious side effects of Nirsevimab include:

• none

Rare side effects of Nirsevimab include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, light-headedness, or passing out

This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Pediatric dosage

IM injection, solution

• 50 mg/0.5 mL prefilled syringe
• 100 mg/mL prefilled syringe

Respiratory Syncytial Virus prevention

• Neonates and infants (first RSV season)
  • Dosage for neonates and infants born during or entering their first RSV season is based on body weight
  • Weighing less than 5 kg: 50 mg IM × 1 dose
  • Weighing 5 kg or more: 100 mg IM × 1 dose
• Children who remain at an increased risk for severe RSV disease (second RSV season)
• Children aged 24 months and younger: 200 mg IM × 1 dose (ie, two 100-mg IM injections)
• Children undergoing cardiac surgery with cardiopulmonary bypass
• Additional dose recommended as soon as the child is stable after surgery to ensure adequate nirsevimab serum levels
• First RSV season
  • Surgery scheduled in 90 days or earlier after receiving nirsevimab: Base additional dose on body weight at the time of additional dose; refer to above weight-based dosing
  • More than 90 days since receiving nirsevimab: Additional dose of 50 mg regardless of body weight
• Second RSV season
  • Surgery scheduled in 90 days or earlier after receiving nirsevimab: Additional dose of 200 mg, regardless of body weight
  • More than 90 days since receiving nirsevimab: Additional dose of 100 mg, regardless of body weight

Dosage Considerations – Should be Given as Follows:

• See "Dosages"

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, healthcare provider, or pharmacist first.

• Nirsevimab has no noted severe interactions with any other drugs.
• Nirsevimab has no noted serious interactions with any other drugs.
• Nirsevimab has no noted moderate interactions with any other drugs.
• Nirsevimab has no noted minor interactions with any other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions, concerns.

Contraindications

• History of serious hypersensitivity reactions, including anaphylaxis, to nirsevimab or its excipients

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Nirsevimab?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Nirsevimab?”

Cautions

• Hypersensitivity
  • Serious hypersensitivity reactions, including anaphylaxis, observed with other human immunoglobulin G1 monoclonal antibodies
  • If signs and symptoms of clinically significant hypersensitivity reaction or anaphylaxis occur, initiate appropriate medications and/or supportive therapy
• Bleeding disorders
  • As with any other IM injections, use caution if administered to infants and children with thrombocytopenia or any coagulation disorder or to individuals on anticoagulation therapy
• RSV diagnostic assays
  • Does not interfere with reverse transcription–polymerase chain reaction (RT-PCR) or rapid antigen detection RSV diagnostic assays that use commercially available antibodies targeting antigenic site I, II, or IV on the RSV fusion (F) protein
  • For immunological assay results that are negative when clinical observations are consistent with RSV infection, it is recommended to confirm using an RT-PCR–based assay

Pregnancy and Lactation

• Controlled studies in pregnant women show no evidence of fetal risk
• Lactation
  • Unknown