February 9, 2016


Varizig Side Effects Center

Pharmacy Editor: Melissa Conrad Stöppler, MD

VariZIG [Varicella Zoster Immune Globulin (Human)] is used to reduce, prevent, or decrease the severity of chicken pox (varicella zoster virus) infections in high-risk people. People most at-risk include children and adults with weak immune systems, pregnant women, and infants . The most common side effects from the use of VariZIG are injection site pain, chills, fever, headaches, vomiting, nausea, joint pain and rash. These symptoms are usually mild.

VariZIG is an injection and is available as in single use 6 mL glass vials. A patient may be administered up to 5 vials depending on body weight. VariZIG may be administered either intravenously or intramuscularly. VariZIG should not be used in patients with a history of allergic reactions to blood products or patients deficient in a blood protein called IgA. VariZIG is not known to interact with other drugs. VariZIG should be given to pregnant women only if clearly needed. It is not known whether VariZIG exits the body through human milk. Because many drugs are excreted in human milk, caution should be exercised when VariZIG is administered to a nursing mother.

Our VariZIG [Varicella Zoster Immune Globulin (Human)] Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is Prescribing information?

The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.

Varizig FDA Prescribing Information: Side Effects
(Adverse Reactions)


The most common adverse drug reactions observed in clinical trials for all subjects and patients are the following:

  • injection site pain (2%)
  • headache (2%).

Less common adverse drug reactions reported include the following:

  • chills,
  • fatigue,
  • rash and
  • nausea.

The following serious adverse reaction is described elsewhere [SEE WARNINGS AND PRECAUTIONS, Clinical Trial Experience]:

Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Three hundred and seventy seven high risk individuals received VARIZIG intramuscularly in two clinical trials which included pregnant women, infants and immunocompromised pediatric and adult patients. The highest incidence of adverse reactions occurred in pregnant women (n=90), including injection site pain (9%), headache (4%), chills (2%) and fatigue (2%). All other adverse reactions occurred in 1% or less of clinical trial subjects within each high risk group. A single incidence of serum sickness (approximately one in 400 patients treated with VARIZIG) was observed in an immunocompromised adolescent patient.

There were six reported adverse events related to the coagulation system (one deep vein thrombosis) in 372 subjects in the open-label, Expanded Access Protocol (EAP); the study was not designed to differentiate between adverse events attributed to the underlying medical condition and adverse reactions to VARIZIG.

Read the entire FDA prescribing information for Varizig (Varicella Zoster Immune Globulin (Human) for Injection)

Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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