Thrombotic events may occur during or following treatment with immune globulin products1, 2, 3. Patients at risk include those with a history of atherosclerosis, multiple cardiovascular risk factors, advanced age, impaired cardiac output, coagulation disorders, prolonged periods of immobilization, and/or known/suspected hyperviscosity. Consider baseline assessment of blood viscosity in patients at risk for hyperviscosity including those with cryoglobulins, fasting chylomicronemia/markedly high triacylglycerols (triglycerides), or monoclonal gammopathies.
Administer VARIZIG intramuscularly only. In patients who have severe thrombocytopenia or any coagulation disorder that would contraindicate intramuscular injections, only administer VARIZIG if the expected benefits outweigh the potential risks.
Severe hypersensitivity reactions may occur following VARIZIG administration. Administer VARIZIG in a setting with appropriate equipment, medication and personnel trained in the management of hypersensitivity, anaphylaxis and shock. In the case of hypersensitivity, discontinue administration of VARIZIG immediately and provide appropriate treatment.
VARIZIG contains trace amounts of IgA (less than 40 micrograms per milliliter). Patients with known antibodies to IgA have a greater risk of severe hypersensitivity and anaphylactic reactions. VARIZIG is contraindicated in IgA deficient patients with antibodies against IgA and history of hypersensitivity reactions [see CONTRAINDICATIONS].
Transmissible Infectious Agents
Because VARIZIG is made from human plasma, it may carry a risk of transmitting infectious agents, e.g., viruses, the variant Creutzfeldt-Jakob disease (vCJD) agent and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent. The plasma donors are screened for the presence of certain infectious agents and the manufacturing process for VARIZIG includes measures to inactivate and remove certain viruses [see DESCRIPTION]. Despite these measures, products derived from human plasma can still potentially transmit diseases. No cases of transmission of viral diseases, vCJD or CJD have been associated with the use of VARIZIG.
Report all infections thought by a physician to have been transmitted by VARIZIG to Cangene Corporation at 1-800-768-2304. Discuss the risks and benefits of this product with the patient before administering it to the patient [see PATIENT INFORMATION].
Use In Specific Populations
Pregnancy category C. Animal reproduction studies have not been conducted with VARIZIG. It also is not known whether VARIZIG can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. VARIZIG should be given to a pregnant woman only if clearly needed.
It is not known whether VARIZIG is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when VARIZIG is administered to a nursing mother.
The dosing recommendations in the treatment of pediatric patients are by body weight [see DOSAGE AND ADMINISTRATION].
The safety and effectiveness of VARIZIG have been evaluated for postexposure prophylaxis in the VARIZIG expanded access clinical trial in 374 pediatric patients, including immunocompromised pediatric patients:
- 94 preterm newborns and infants,
- 53 term newborns,
- 45 infants and toddlers,
- 176 children and,
- 43 adolescents.
In the EAP, follow up data were available for 110 VARIZIG treatments in infants (including newborns, pre-term infants, and infants < 1 year old). Three severe infections were reported, all three with pox count > 100, one of which also had pneumonia and another one also developed probable varicella encephalitis.
Clinical studies of VARIZIG administered intramuscularly for post-exposure prophylaxis did not include sufficient numbers of geriatric subjects (aged 65 and over) to determine whether they respond differently from younger subjects.
Use caution when administering VARIZIG to patients age 65 and over who are judged to be at increased risk of thrombotic events [see WARNINGS AND PRECAUTIONS]. Do not exceed recommended doses and administer VARIZIG intramuscularly only.
In the EAP, both adult (n=37) and pediatric immunocompromised subjects (n=235) were treated. Twelve immunocompromised subjects developed clinical varicella and none developed varicella pneumonitis; however at least five are reported to have received concomitant acyclovir and due to incomplete reporting, it is not known if others also received acyclovir.
1. Dalakas MC. High-dose intravenous immunoglobulin and serum viscosity: risk of precipitating thromboembolic events. Neurology. 1994; 44:223-6.
2. Woodruff RK, Grigg AP, Firkin FC, Smith IL. Fatal thrombotic events during treatment of autoimmune thrombocytopenia with intravenous immunoglobulin in elderly patients. Lancet. 1986; 2:217-8.
3. Wolberg AS, Kon RH, Monroe DM, Hoffman M. Coagulation factor XI is a contaminant in intravenous immunoglobulin preparations. Am J Hematol. 2000; 65:30-4.This monograph has been modified to include the generic and brand name in many instances.
Last reviewed on RxList: 3/14/2016
Additional VariZIG Information
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