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Synagis Side Effects

Generic name: palivizumab

Medically reviewed by Last updated on Feb 28, 2024.

Note: This document contains side effect information about palivizumab. Some dosage forms listed on this page may not apply to the brand name Synagis.

Applies to palivizumab: intramuscular solution.

Serious side effects of Synagis

Along with its needed effects, palivizumab (the active ingredient contained in Synagis) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking palivizumab:

More common

Incidence not known

Other side effects of Synagis

Some side effects of palivizumab may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

For Healthcare Professionals

Applies to palivizumab: intramuscular powder for injection, intramuscular solution.


Frequency not reported: Arrhythmia (during studies of congenital heart disease patients)[Ref]


Common (1% to 10%): Nausea, vomiting, diarrhea[Ref]


Frequency not reported: Anaphylaxis, anaphylactic shock (sometimes fatal)

Postmarketing reports: Angioedema[Ref]


Common (1% to 10%): Injection site reactions[Ref]


Very common (10% or more): Pyrexia[Ref]


Very common (10% or more): Rash

Uncommon (0.1% to 1%): Urticaria

Frequency not reported: Pruritus[Ref]


The most serious adverse reactions are anaphylaxis and other acute hypersensitivity reactions.[Ref]


Uncommon (0.1% to 1%): Thrombocytopenia (mild), eosinophilia (mild)

Postmarketing reports: Severe thrombocytopenia (platelet count less than 50,000/microliter)[Ref]

Nervous system

Uncommon (0.1% to 1%): Convulsions[Ref]


Frequency not reported: Cyanosis during studies of congenital heart disease patients

Postmarketing reports: Dyspnea, asthma, bronchospasm[Ref]

Frequently asked questions


1. (2001) "Product Information. Synagis (palivizumab)." Ross Product Division Pharmaceuticals

2. Boeckh M, Berrey MM, Bowden RA, Crawford SW, Balsley J, Corey L (2001) "Phase 1 evaluation of the respiratory syncytial virus-specific monoclonal antibody palivizumab in recipients of hematopoietic stem cell transplants." J Infect Dis, 184, p. 350-4

3. Cerner Multum, Inc. "UK Summary of Product Characteristics."

4. Pharmaceutical Society of Australia (2006) APPGuide online. Australian prescription products guide online.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.