"What is Idiopathic Thrombocytopenic Purpura (ITP)?
Idiopathic thrombocytopenic purpura (ITP) is a bleeding condition in which the blood doesn't clot as it should. This is due to a low number of blood cell fragments called platelets (P"...
Severe hypersensitivity reactions may occur with IGIV products, including GAMUNEX-C. In case of hypersensitivity, discontinue GAMUNEX-C infusion immediately and institute appropriate treatment. Medications such as epinephrine should be available for immediate treatment of acute hypersensitivity reaction.
GAMUNEX-C contains trace amounts of IgA (average 46 micrograms/mL). Patients with known antibodies to IgA may have a greater risk of developing potentially severe hyper sensitivity and anaphylactic reactions. It is contraindicated in IgA deficient patients with antibodies against IgA and history of hypersensitivity reaction. (see CONTRAINDICATIONS)
Assure that patients are not volume depleted prior to the initiation of the infusion of GAMUNEX-C. Periodic monitoring of renal function and urine output is particularly important in patients judged to have a potential increased risk for developing acute renal failure. Assess renal function, including measurement of blood urea nitrogen (BUN)/serum creatinine, prior to the initial infusion of GAMUNEX-C and again at appropriate intervals thereafter. If renal function deteriorates, consider discontinuation of GAMUNEX-C. (see PATIENT INFORMATION) For patients judged to be at risk for developing renal dysfunction, including patients with any degree of pre-existing renal insufficiency, diabetes mellitus, age greater than 65, volume depletion, sepsis, paraproteinemia, or patients receiving known nephrotoxic drugs, administer GAMUNEX-C at the minimum infusion rate practicable [less than 8 mg IG/kg/min (0.08 mL/kg/min)]. (see DOSAGE AND ADMINISTRATION)
Hyperproteinemia, Increased Serum Viscosity, and Hyponatremia
Hyperproteinemia, increased serum viscosity and hyponatremia may occur in patients receiving IGIV treatment, including GAMUNEX-C. It is clinically critical to distinguish true hyponatremia from a pseudohyponatremia that is associated with concomitant decreased calculated serum osmolality or elevated osmolar gap, because treatment aimed at decreasing serum free water in patients with pseudohyponatremia may lead to volume depletion, a further increase in serum viscosity and a possible predisposition to thromboembolic events. 
Thrombotic events have been reported following IGIV treatment and may occur in patients receiving IGIV treatment, including GAMUNEX-C. [9-11] Patients at risk may 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 or 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. For patients judged to be at risk of developing thrombotic events, administer GAMUNEX-C at the minimum rate of infusion practicable. (see DOSAGE AND ADMINISTRATION)
Aseptic Meningitis Syndrome (AMS)
AMS may occur infrequently with IGIV treatment, including GAMUNEX-C. Discontinuation of IGIV treatment has resulted in remission of AMS within several days without sequelae. The syndrome usually begins within several hours to two days following IGIV treatment. AMS is characterized by the following symptoms and signs: severe headache, nuchal rigidity, drowsiness, fever, photophobia, painful eye movements, nausea and vomiting. Cerebrospinal fluid (CSF) studies are frequently positive with pleocytosis up to several thousand cells per cu mm, predominantly from the granulocytic series, and with elevated protein levels up to several hundred mg/dL, but negative culture results. Conduct a thorough neurological examination on patients exhibiting such symptoms and signs including CSF studies, to rule out other causes of meningitis. AMS may occur more frequently in association with high doses (2 g/kg) and/or rapid infusion of IGIV.
IGIV products, including GAMUNEX-C, may contain blood group antibodies which may act as hemolysins and induce in vivo coating of red blood cells (RBCs) with immunoglobulin, causing a positive direct antiglobulin reaction and, rarely, hemolysis. [12-14] Delayed hemolytic anemia can develop subsequent to IGIV therapy due to enhanced RBC sequestration, and acute hemolysis consistent with intravascular hemolysis, has been reported. Monitor patients for clinical signs and symptoms of hemolysis.  (see PATIENT INFORMATION) If signs and/or symptoms of hemolysis are present after GAMUNEX-C infusion, perform appropriate confirmatory laboratory testing.
Transfusion-related Acute Lung Injury (TRALI)
Noncardiogenic pulmonary edema may occur in patients following treatment with IGIV products, including GAMUNEX-C.  TRALI is characterized by severe respiratory distress, pulmonary edema, hypoxemia, normal left ventricular function, and fever. Symptoms typically occur within 1 to 6 hours after treatment.
Monitor patients for pulmonary adverse reactions. (see PATIENT INFORMATION) If TRALI is suspected, perform appropriate tests for the presence of anti-neutrophil and anti-HLA antibodies in both the product and patient serum. TRALI may be managed using oxygen therapy with adequate ventilatory support.
The high dose regimen (1 g/kg 1-2 days) is not recommended for individuals with expanded fluid volumes or where fluid volume may be a concern.
Transmissible Infectious Agents
Because GAMUNEX-C is made from human blood, it may carry a risk of transmitting infectious agents, e.g., viruses, and theoretically, the Creutzfeldt- Jakob disease (CJD) agent. No cases of transmission of viral diseases or CJD have ever been identified for GAMUNEX-C. ALL infections suspected by a physician possibly to have been transmitted by this product should be reported by the physician or other healthcare provider to Grifols Therapeutics Inc. [1-800-520-2807]
After infusion of IgG, the transitory rise of the various passively transferred antibodies in the patient's blood may yield positive serological testing results, with the potential for misleading interpretation.
Passive transmission of antibodies to erythrocyte antigens (e.g., A, B, and D) may cause a positive direct or indirect antiglobulin (Coombs') test. Patients with known renal dysfunction or renal failure, including patients with pre-existing renal insufficiency, diabetes mellitus, age greater than 65, volume depletion, sepsis, paraproteinemia, or those receiving nephrotoxic agents, should be clinically assessed and monitored (BUN, creatinine), as appropriate, during therapy with GAMUNEX-C.
Consider baseline assessment of blood viscosity in patients at risk for hypervisocosity, including those with cryoglobulins, fasting chylomicronemia/ markedly high triacylglycerols (triglycerides), or monoclonal gammopathies.
Patient Counseling Information
(see BOXED WARNING and WARNINGS AND PRECAUTIONS Sections)
Inform patients to immediately report the following signs and symptoms to their healthcare provider:
- Decreased urine output, sudden weight gain, fluid retention/edema, and/or shortness of breath (see WARNINGS AND PRECAUTIONS)
- Acute chest pain, shortness of breath, leg pain, and swelling of the legs/feet (see WARNINGS AND PRECAUTIONS)
- Severe headache, neck stiffness, drowsiness, fever, sensitivity to light, painful eye movements, nausea, and vomiting (see WARNINGS AND PRECAUTIONS)
- Increased heart rate, fatigue, yellowing of the skin or eyes, and dark-colored urine (see WARNINGS AND PRECAUTIONS)
- Trouble breathing, chest pain, blue lips or extremities, and fever (see WARNINGS AND PRECAUTIONS)
Inform patients that GAMUNEX-C is made from human plasma and may contain infectious agents that can cause disease. While the risk GAMUNEXC can transmit an infectious agent has been reduced by screening plasma donors for prior exposure, testing donated plasma, and by inactivating or removing certain viruses during manufacturing, patients should report any symptoms that concern them. (see WARNINGS AND PRECAUTIONS) Inform patients that GAMUNEX-C can interfere with their immune response to live viral vaccines such as measles, mumps and rubella. Inform patients to notify their healthcare professional of this potential interaction when they are receiving vaccinations. (see DRUG INTERACTIONS)
Home Treatment for Primary Humoral Immunodeficiency with Subcutaneous Infusion
Provide the patient with instructions on subcutaneous infusion for home treatment, if the physician believes that home administration is appropriate for the patient. Include the type of equipment to be used along with its maintenance, proper infusion techniques, selection of appropriate infusion sites (e.g., abdomen, thighs, upper arms, and/or lateral hip), maintenance of a treatment diary, and measures to be taken in case of adverse reactions in the patient instructions.
Use In Specific Populations
Pregnancy Category C. Animal reproduction studies have not been conducted with GAMUNEX-C. It is not known whether GAMUNEX-C can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. GAMUNEX-C should be given to a pregnant woman only if clearly needed. Immunoglobulins cross the placenta from maternal circulation increasingly after 30 weeks of gestation. [18-19]
Use of GAMUNEX-C has not been evaluated in nursing mothers.
Treatment of Primary Humoral Immunodeficiency
GAMUNEX-C was evaluated in 18 pediatric subjects (age range 0-16 years). Twenty-one percent of PI subjects exposed to GAMUNEX-C were children. Pharmacokinetics, safety and efficacy were similar to those in adults with the exception that vomiting was more frequently reported in pediatrics (3 of 18 subjects). No pediatric-specific dose requirements were necessary to achieve serum IgG levels.
SC GAMUNEX-C was evaluated in only three pediatric subjects (age range 13-15) with PI. This number of pediatric subjects was too small for separate evaluation of pharmaco kinetics and safety to determine whether they respond differently from adults. (see Clinical Studies) Efficacy and safety in pediatric patients using the SC route of administration have not been established.
Treatment of Idiopathic Thrombocytopenic Purpura
For treatment of ITP, GAMUNEX-C must be administered by the intravenous route.
GAMUNEX-C was evaluated in 12 pediatric subjects with acute ITP. Twenty-five percent of the acute ITP subjects exposed to GAMUNEX-C were children. Pharmacokinetics, safety and efficacy were similar to those in adults with the exception that fever was more frequently reported in pediatrics (6 of 12 subjects). No pediatric-specific dose requirements were necessary to achieve serum IgG levels. One subject, a 10-year-old boy, died suddenly from myocarditis 50 days after his second infusion of GAMUNEX-C. The death was judged to be unrelated to GAMUNEX-C.
Treatment of Chronic Inflammatory Demyelinating Polyneuropathy
The safety and effectiveness of GAMUNEX-C has not been established in pediatric subjects with CIDP.
Use caution when administering GAMUNEX-C to patients age 65 and over who are judged to be at increased risk for developing thromboembolic events or renal insufficiency. (see BOXED WARNING, WARNINGS AND PRECAUTIONS) Do not exceed recommended doses, and administer GAMUNEX-C at the minimum infusion rate practicable. Clinical studies of GAMUNEX-C did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.
8. Steinberger BA, Ford SM, Coleman TA. Intravenous Immunoglobulin Therapy Results in Post-infusional Hyperproteinemia, Increased Serum Viscosity, and Pseudohyponatremia. Am J Hematol 73:97-100 (2003).
9. Dalakas MC. High-dose intravenous Immunoglobulin and serum viscosity: risk of precipitating thromboembolic events. Neurology, 44:223-226.
10. Woodruff RK, Grigg AP, Firkin FC, Smith IL. Fatal thrombotic events during treatment of autoimmune thrombocytopenia with intravenous immunoglobulin in elderly patients. Lancet 1986;2:217-218.
11. Wolberg AS, Kon RH, Monroe DM, Hjoffman M. Coagulation factor XI is a contaminant in intravenous immunoglobulin preparations. Am J Hematol 2000; 65,30-34.
12. Copelan EA, Stohm PL, Kennedy MS, Tutschka PJ. Hemolysis following intravenous immune globulin therapy. Transfusion 1986;26:410-412.
13. Thomas MJ, Misbah SA, Chapel HM, Jones M, Elrington G, Newsom-Davis J. Hemolysis after high-dose intravenous Ig. Blood 1993;15:3789.
14 Wilson JR, Bhoopalam N, Fisher M. Hemolytic anemia associated with intravenous immunoglobulin. Muscle & Nerve 1997; 20:1142-1145.
15. Kessary-Shoham H, Levy Y, Shoenfeld Y, Lorber M, Gershon H. In vivo administration of intravenous immunoglobulin (IVIg) can lead to enhanced erythrocyte sequestration. J Autoimmune 1999; 13:129-135.
16. Rizk A, Gorson KC, Kenney L, Weinstein R. Transfusion-related acute lung injury after the infusion of IVIG. Transfusion 2001:41:264-268.
17. Pierce LR, Jain N. Risks associated with the use of intravenous immunoglobulin. Trans Med Rev 2003; 17,241-251.
18. Hammarstrom L, Smith CIE. Placental transfer of intravenous immunoglobulin. Lancet 1986: 1:681.
19. Sidiropoulos D, Herrmann U, Morell A, von Muralt G, Barandun S. Transplacental passage of intravenous immunoglobulin in the last trimester of pregnancy. J Pediatr 1986; 109:505-508.
Last reviewed on RxList: 1/14/2013
This monograph has been modified to include the generic and brand name in many instances.
Additional Gamunex-C Information
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