What causes CIDP?
The exact cause of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is unknown, but it is considered an autoimmune disorder
In a healthy person, the body’s immune system protects against disease by making antibodies to fight off infections caused by viruses and bacteria.1
In people with CIDP, the body’s immune system mistakes myelin as foreign and attacks it.1
In people with CIDP, many parts of the immune system (as shown here) attack and destroy the protective covering of the nerves of the arms and legs (peripheral nerves). Over time, this destruction leads to weakness, numbness, and tingling in the arms and legs.
Important Safety Information
GAMUNEX®-C (immune globulin injection [human], 10% caprylate/chromatography purified) is approved to treat primary humoral immunodeficiency disease (PIDD). If you have PIDD, you may take GAMUNEX-C under the skin (subcutaneously) or in a vein (intravenously). GAMUNEX-C is also approved to treat idiopathic thrombocytopenic purpura (ITP) and chronic inflammatory demyelinating polyneuropathy (CIDP). If you have ITP or CIDP, you may only take GAMUNEX-C intravenously.
If you take GAMUNEX-C or a similar immune globulin product, you could experience a serious and life-threatening blood clot (thromboembolism), which may include pain and/or swelling of an arm or leg with warmth over the affected area, discoloration of an arm or leg, unexplained shortness of breath, chest pain or discomfort that worsens on deep breathing, unexplained rapid pulse, numbness, or weakness on one side of the body. You are more likely to develop a blood clot if you have a history of hardening of the arteries (atherosclerosis), stroke, heart attack, or heart failure (low volume of blood pumped by the heart). You may also be more likely to get a blood clot if you are elderly, if you have a blood clotting disorder, if you are inactive for long periods of time (such as long bed rest), if you use estrogens, or if you have thickening of your blood. For patients at risk, GAMUNEX-C should be administered at the lowest dose and slowest infusion rate that is practical. However, blood clots may occur in the absence of any of the known risk factors. Patients should be well hydrated by drinking enough water before GAMUNEX-C is administered. Tell your doctor immediately if your medical history is similar to what is described here, and especially if you start having any of these symptoms while taking GAMUNEX-C.
If you take GAMUNEX-C or a similar immune globulin product intravenously, you could experience serious kidney disease and death. You may have symptoms of decreased urination, sudden weight gain, swelling in your legs (edema), or shortness of breath. You are more likely to develop serious kidney disease if you already have a kidney problem, have Type II diabetes mellitus, or are older than 65. You are more likely to develop serious kidney disease if you are dehydrated, have a blood infection (sepsis), have high protein content in your blood, or if you are receiving other medicines that are harmful to your kidneys. Tell your doctor immediately if your medical history is similar to what is described here, and especially if you start having any of these symptoms while taking GAMUNEX-C.
You are more likely to develop serious kidney disease if you take an intravenous immune globulin product that contains sugar (sucrose). GAMUNEX-C does not contain sugar. If your situation makes you more likely to experience serious kidney disease, you should take GAMUNEX-C at the lowest concentration available and the slowest infusion rate that is practical.
Do not take GAMUNEX-C if you have an allergy to immune globulin. Tell your doctor if you have had a serious reaction to other medicines that contain human immune globulin. Also tell your doctor if you have immunoglobulin A (IgA) deficiency. If you have a serious reaction while taking GAMUNEX-C, stop taking it immediately and tell your doctor.
Periodic monitoring of kidney function and urine output is particularly important in patients more likely to experience severe kidney disease.
You could experience other serious and life-threatening problems due to immune globulin. You could get a lung problem called transfusion-related acute lung injury, also known as TRALI, or have fluid in the lungs (pulmonary edema) that is not the result of heart failure. You could get a blood problem called hemolytic anemia (common symptoms include increased heart rate, fatigue, yellow skin or eyes, and dark-colored urine). You could get aseptic meningitis, a type of brain inflammation with symptoms of severe headache, stiff neck, fatigue, fever, sensitivity to light, painful eye movements, nausea, and vomiting.
If you have higher than normal body fluid volumes or if you have a condition where increasing body fluid volume may be a concern, a higher dose, such as 1g/kg for 1-2 days, is not recommended.
Because GAMUNEX-C is made from human blood, it may carry a risk of transmitting infectious agents such as viruses, and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent.
You may not take GAMUNEX-C subcutaneously if you have ITP. If you have ITP and take GAMUNEX-C subcutaneously, you could experience a very serious and life-threatening black and blue wound (hematoma, which is a pocket of blood within a tissue).
After you take GAMUNEX-C, your blood antibody levels may rise, which could cause some blood antibody tests to give false results.
The most common side effects in a clinical study with PIDD patients who got subcutaneous injections of GAMUNEX-C were redness, swelling and itching at the infusion site, headache, fatigue, pain (including pain in the back, joints arms, and legs), and fever. In clinical studies with PIDD patients who got GAMUNEX-C intravenously, the most common side effects were headache, cough, nausea, inflammation of the throat (which is the most common cause of sore throat), and rash and redness, swelling and itching at the injection site. In a clinical study with CIDP patients who got GAMUNEX-C intravenously, the most common side effects were headache, fever, chills, high blood pressure, rash, nausea, and physical weakness. In clinical trials with ITP patients who got GAMUNEX-C intravenously, the most common side effects were headache, vomiting, fever, nausea, back pain, and rash.
The most serious side effects in clinical studies were a blood clot to the lung (pulmonary embolism) in 1 patient with a history of this condition (in CIDP), a flare-up of an existing type of anemia (autoimmune pure red cell aplasia) in 1 patient (in PIDD), and heart inflammation (myocarditis) in 1 patient (in ITP).
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.
- Fauci AS, Braunwald E, Kasper DL, et al, eds. Harrison’s Principles of Internal Medicine. 17th ed. New York, NY: McGraw-Hill; 2008.