Gamunex-C
Gamunex-C is an immunoglobulin (antibody) infusion known as intravenous immunoglobulin (IVIG). It treats certain immune-related conditions, including primary immunodeficiency (PI) and chronic inflammatory demyelinating polyneuropathy (CIDP). Gamunex-C is typically infused through the vein, but can also be infused under the skin for PI. How often you receive a dose differs depending on your condition, but can range from weekly to every 4 weeks. Gamunex-C can raise your risk of serious side effects, including blood clots and kidney problems.
What is Gamunex-C?
What is Gamunex-C used for?
- Primary humoral immunodeficiency or PI in adults and children ages 2 years and older
- Prevent bleeds during surgery in adults and children with immune thrombocytopenia (ITP)
- Chronic inflammatory demyelinating polyneuropathy (CIDP) in adults
How Gamunex-C works
Gamunex-C is a type of intravenous immune globulin (IVIG). It contains immunoglobulin G (IgG), which is one type of antibody that your immune system naturally makes to help you fight off things that make you sick, like viruses, bacteria, and fungi.
People with primary immunodeficiency (PI) don't have enough IgG in their bodies. This raises the risk of serious infections. Gamunex-C is used to temporarily replace the missing IgG so that people with PI are less likely to get sick.
People with immune thrombocytopenia (ITP) or chronic inflammatory demyelinating polyneuropathy (CIDP) have immune systems that attack their platelets or nerves by mistake. How Gamunex-C helps these conditions isn't well-understood. But this medication is thought to work by calming the immune system.
Drug facts
| Common Brands | Gamunex C |
|---|---|
| Drug Class | Immune globulin |
| Controlled Substance Classification | Not a controlled medication |
| Generic Status | No lower-cost generic available |
| Availability | Prescription only |
Side effects of Gamunex-C
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Infusion site reactions
- Cough
- Stuffy nose
- Headache
- Nausea
- Fever
- Diarrhea
- Stomach pain
- Joint pain
- Inflammation of sinuses
- Rash
Less Common Side Effects
- Asthma
- Feeling tired
- Upper respiratory tract infection
- Sore throat
- Depression
- Vomiting
- High blood pressure
- Chills
- Bruising
Gamunex-C serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Kidney problems: tiredness, trouble sleeping, dry and itchy skin, low appetite, low urine output, foamy urine, bloody urine, muscle cramps
- Blood clots: lungs (cough, difficulty breathing, chest pain), legs (redness, pain, tenderness, swelling of the skin), heart attack (chest pain, pain in the arms or shoulders, pain in the neck or jaw), stroke (difficulty speaking, numbness on one side of the body, confusion)
- Serious allergic reaction (anaphylaxis): difficulty breathing, hives, itching, fast heartbeat, tightness in the throat, nausea, stomach pain, dizziness, lightheadedness, swelling in the face or tongue
- Swelling and inflammation of the brain: severe headache, neck stiffness, sleepiness, fever, sensitivity to light, painful eye movements, nausea, vomiting
- Hemolytic anemia (low red blood cell count): tiredness, dizziness, weakness, high heart rate, yellowing of the skin or eyes, dark-colored urine
- Lung problems (TRALI): difficulty breathing, fluid in lungs (wheezing or rattling while breathing), low blood oxygen levels (headaches, feeling confused, or chest pain), fever
The following Gamunex-C side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Blood clot—pain, swelling, or warmth in the leg, shortness of breath, chest pain
- Fever, neck pain or stiffness, sensitivity to light, headache, nausea, vomiting, confusion, which may be signs of meningitis
- Hemolytic anemia—unusual weakness or fatigue, dizziness, headache, trouble breathing, dark urine, yellowing skin or eyes
- Kidney injury—decrease in the amount of urine, swelling of the ankles, hands, or feet
- Low sodium level—muscle weakness, fatigue, dizziness, headache, confusion
- Shortness of breath or trouble breathing, cough, unusual weakness or fatigue, blue skin or lips
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
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Pros and cons of Gamunex-C
Pros
- Works well to treat PI, ITP, and CIDP
- Can safely be given to children with certain conditions
- Can be given SC (under the skin) at home for PI, if prescriber approves
Cons
- IV infusion lasts a few hours
- Has a lot of potential risks, such as kidney and lung problems
- People age 65 years and older have a higher risk of serious side effects
Pharmacist tips for Gamunex-C
- Make sure to mark your appointments on your calendar for when you need to receive Gamunex-C or get any blood tests done. If you accidentally miss a dose, talk with your prescriber right away about rescheduling your appointment.
- Watch the instructional video to help you prepare for what to expect from Gamunex-C infusions. If you're going to an infusion center, make sure to dress comfortably and bring something to help you pass the time, such as a book or some music, because the infusions can take several hours depending on your needs.
- Gamunex-C raises your risk for blood clots. Get medical help right away if you experience symptoms of blood clot, including cough, difficulty breathing, chest pain, headache, trouble speaking, or weakness on one side of your body.
- Gamunex-C can cause serious kidney problems. Contact your prescriber right away if you experience symptoms of kidney problems, such as tiredness, trouble sleeping, dry and itchy skin, difficulty making urine.
- Before getting any vaccines, let your prescriber know you're receiving or have recently received Gamunex-C because it can interfere with how your body responds to live vaccines (e.g., measles, mumps, and rubella (MMR) vaccine).
More tips for Gamunex-C subcutaneous infusion at home (PI only):
- Gamunex-C vials can be stored in the refrigerator for 3 years from the date it was manufactured. They can also be stored at room temperature for up to 6 months. Store vials in the original packaging away from light.
- Before giving a dose, take the vials out of the refrigerator and let them warm up to room temperature, which will be about 1 hour. Don't shake the vials.
- Gamunex-C can be infused in the side of your arms, stomach, lower back, or thighs. Your prescriber might recommend to use multiple infusion sites at the same time. Make sure they're at least 2 inches apart from each other.
- Keep a record of your infusions by removing the label that has the vial's information and placing it in a journal. Bring this journal each time when you see your prescriber.
Risks and warnings for Gamunex-C
Gamunex-C can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Kidney failure
- Risk factors: Age greater than 65 years | Kidney problems | Type 2 diabetes | Sepsis | Having high amounts of certain proteins in blood (Paraproteinemia) | Not having enough fluids | Taking medications that can cause kidney problems
Gamunex-C can cause severe and life-threatening kidney problems. The risk is higher for certain people, like older adults and people who are dehydrated. Your prescriber will order labs to check your kidney health as needed before and during treatment Gamunex-C. If your kidney health worsens during treatment, your prescriber might slow down or stop your infusion. Contact your prescriber if you develop any signs or symptoms of kidney failure, including tiredness, trouble sleeping, dry and itchy skin, low appetite, and muscle cramps.
Blood clots
- Risk factors: Older age | Not moving much or on bed rest | History of blood clots | Having other medical conditions that raise your risk of clots | Taking medications that contain estrogen | Central IV lines | High plasma viscosity (having thick plasma) | Heart problems
Gamunex-C can put you at greater risk of getting a blood clot, especially if you're already at risk of getting clots in various parts of your body. This is because this medication can make it more difficult for blood to flow. Your prescriber will monitor you closely while you receive Gamunex-C. Symptoms of a blood clot might be different depending on the location of the clot, but they can include chest pain, difficulty breathing, swelling or warmth in the legs, and weakness of the face, legs, or arms. Call 911 if you have any of the symptoms above because this is a medical emergency. Your prescriber might adjust your dose of Gamunex-C or might have you stop taking it.
High protein levels and low sodium levels
Gamunex-C can cause serious side effects, such as high protein levels in your blood and low blood sodium levels. Your prescriber will measure your labs to assess your risk for these serious side effects and will adjust your dose of Gamunex-C as necessary.
Serious allergic reactions
Serious allergic reactions to Gamunex-C are possible, including life-threatening reactions like anaphylaxis (closing of the throat). If you notice dizziness, a choking sensation, sweating, dizziness, nausea, swelling around your eyes, swelling of the lips or tongue, or difficulty breathing after using Gamunex-C, get medical attention right away.
Swelling in the brain
- Risk factors: Doses of 2 grams/kg or higher | Receiving Gamunex-C too quickly
Although rare, Gamunex-C can cause swelling and inflammation of the brain (called aseptic meningitis). You can experience symptoms as early as several hours to 2 days after receiving Gamunex-C, but these symptoms typically go away within several days after you stop this medication. Contact your prescriber if you experience severe headache, neck stiffness, sleepiness, fever, sensitivity to light, painful eye movements, nausea, or vomiting.
Hemolytic anemia (low red blood cells)
- Risk factors: Doses of 2 grams/kg or higher | Non-O blood group | History of anemia | History of lung or heart problems
Gamunex-C can cause hemolytic anemia, which is when your red blood cells are broken down. Your prescriber will monitor your blood cell counts before and during treatment. Contact your healthcare team if you experience symptoms such as tiredness, dizziness, and weakness.
Serious lung problem
Gamunex-C can cause a condition called transfusion-related acute lung injury (also known as TRALI). TRALI is a condition where fluid is backed up in your lungs after receiving Gamunex-C. This problem typically happen within 1 to 6 hours after you receive Gamunex-C. Let your prescriber know right away if you experience symptoms such as severe breathing problems, fluid in the lungs, low blood oxygen levels, and fever.
Risk of infection
- Risk factors: Medical conditions that lower your immune system | Taking medications that can lower your immune system
Because Gamunex-C is made from human blood products, there's a risk that it might contain viruses that can make you sick. But your risk of infection is pretty low since donors of these blood products are screened. Also, there are high manufacturing standards put into place to make sure the viruses are killed or removed. To prevent serious infections in the rare case that your doses of Gamunex-C are affected, let your prescriber know right away if you start to feel sick or have symptoms such as feeling confused and anxious, or having trouble maintaining your balance.
Gamunex-C dosage
Vial| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 10ml of 10% | 4 vials | $594.54 | $148.64 |
| 25ml of 10% | 1 vial | $373.93 | $373.93 |
| 50ml of 10% | 1 vial | $741.61 | $741.61 |
| 100ml of 10% | 1 vial | $1,476.97 | $1,476.97 |
| 200ml of 10% | 2 vials | $5,889.13 | $2,944.57 |
| 400ml of 10% | 1 vial | $5,889.13 | $5,889.13 |
Typical dosage for Gamunex-C
Your prescriber will determine your dose of Gamunex-C based on body weight.
-
Primary immunodeficiency (PI)
- Ages 2 years and older:
- Infusion into the veins (intravenous or IV): The typical dose is 300 mg/kg to 600 mg/kg IV once every 3 to 4 weeks. Your prescriber might give you another dose if you're at risk of measles exposure (e.g., traveling) or if you were exposed to measles.
- Infusion under the skin (subcutaneous or SC): Your prescriber will determine your dose based on your previous dose of IVIG. It's typically infused under the skin weekly.
- Ages 2 years and older:
-
Idiopathic thrombocytopenic purpura (ITP)
- Adults and children: The typical dose is 2 grams/kg infused IV, split into smaller doses and given over 2 to 5 days.
-
Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Adults: The typical starting dose is 2 grams/kg, split into smaller doses and infused IV over 2 to 4 days. The typical maintenance dose is 1 gram/kg infused over 1 to 2 days, once every 3 weeks.
Your prescriber will adjust your Gamunex-C dose based on if it's helping your condition and if you're having side effects. If your condition improves before you finish the treatment course, it's possible you might not need to receive the remaining doses.
How much does Gamunex-C cost?
$373.93
Gamunex-C contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Gamunex-C will not be safe for you to take.
- Severe allergy to human immune globulin
- People with low immunoglobulin A who also have IgA antibodies
What are alternatives to Gamunex-C?
Conditions where your immune system is missing or not working like it should:
Medical conditions that happen when your immune system is missing components or not working like it should:
