Gamunex-C (immune globulin [human]) can cause mild to serious side effects. More common side effects include headache. If Gamunex-C’s side effects become bothersome for you or your child, ask the doctor about coping tips or other treatment options.

Gamunex-C is prescribed to treat:

Keep reading to learn about the common, mild, and serious side effects Gamunex-C can cause. To learn more about this medication, including its uses, dosage, and cost, read this Gamunex-C overview.

Gamunex-C has boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Boxed warnings for Gamunex-C” section.

Gamunex-C can cause certain side effects, some more common than others. These side effects may be temporary, lasting a few days to weeks. Talk with your doctor or your child’s doctor if side effects do not go away, get worse, or become too difficult to tolerate.

When treating primary humoral immunodeficiency (PI)

The following table lists some, but not all, of Gamunex-C’s more commonly reported side effects in people receiving it for PI.

Side effectIn people receiving it by intravenous (IV) infusionIn people receiving it by subcutaneous infusion
headache ✓ ✓
nausea ✓ ✓
diarrhea ✓ ✓
sinusitis (inflammation in the sinuses) ✓ ✓
increased cough ✓
rhinitis (inflammation of the nasal cavity) ✓
reaction where the drug was infused ✓
fatigue (low energy) ✓
upper respiratory tract infection ✓
joint pain ✓

For more information about some of these side effects, see the “Tips for managing side effects” section.

When treating idiopathic thrombocytopenic purpura (ITP)

More common side effects in people receiving Gamunex-C for ITP include:

For more information about some of these side effects, see the “Tips for managing side effects” section.

When treating chronic inflammatory demyelinating polyneuropathy (CIDP)

More common side effects in people receiving Gamunex-C for CIDP include:

For more information about some of these side effects, see the “Tips for managing side effects” section.

Mild side effects have been reported with Gamunex-C. They include those listed here and others noted in the drug’s prescribing information.

  • stuffy or runny nose
  • cough
  • headache or migraine
  • fever
  • nausea
  • diarrhea
  • pain, including in the joints, legs, or arms
  • pharyngitis (sore throat)
  • fatigue (low energy)
  • reaction where the drug was infused, such as pain, swelling, or skin discoloration
  • sinusitis (inflammation in the sinuses)

In most cases, these side effects should be temporary, and some can be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor, your child’s doctor, or a pharmacist. Do not stop Gamunex-C treatment unless the doctor recommends it.

For more information about some of these side effects, see the “Tips for managing side effects” section.

Gamunex-C may cause serious side effects. They include those listed here and others noted in Gamunex-C’s prescribing information.

For more information about some of these side effects, see the “Boxed warnings for Gamunex-C” section.

If you or your child develops serious side effects during treatment with Gamunex-C, call the doctor right away. If the side effects seem life threatening or you think it’s a medical emergency, immediately call 911. Or call your local emergency number.

Gamunex-C is prescribed to treat:

Side effects in children receiving Gamunex-C are similar to those reported in adults. (See the common, mild, and serious side effects sections earlier in this article.) But the following list notes some exceptions in children’s treatment compared with adults’ treatment:

  • For children and adults receiving Gamunex-C to treat PI: Vomiting was reported more commonly in children than in adults receiving Gamunex-C by IV infusion.
  • For children and adults receiving Gamunex-C to treat ITP: Fever was reported more commonly in children than in adults receiving Gamunex-C.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing the experience helps make medication safer for everyone. It gives doctors and researchers more information about how the drug works in real life. If you or your child develops a side effect during treatment with Gamunex-C, you can tell the FDA about it. Visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, Gamunex-C can cause an allergic reaction. In general, symptoms of an allergic reaction can be mild or serious.

What might help

If you or your child has mild symptoms of an allergic reaction, such as a mild rash, call your doctor or your child’s doctor right away. They may suggest a treatment to manage the symptoms. They can also determine whether you or your child should continue Gamunex-C treatment.

If you or your child has symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911. Or call your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

Your doctor or your child’s doctor can confirm whether you or your child has had a serious allergic reaction to Gamunex-C. If they confirm this, they may switch you or your child to a different treatment.

Gamunex-C has boxed warnings. A boxed warning is the most serious warning from the FDA.

Risk of blood clots

Treatment with immune globulin medications can cause a blood clot as a side effect. Gamunex-C is an immune globulin medication, but this side effect was rare in studies of the drug. Blood clots can be life threatening and sometimes fatal.

Blood clots can occur in anyone treated with Gamunex-C. But some risk factors increase this risk as a side effect of Gamunex-C treatment, including:

  • past blood clot
  • being age 65 years or older
  • immobility for long periods of time
  • shortness of breath
  • chest pain or chest discomfort that worsens with deep breathing
  • pain, discolored skin, or swelling in the affected area of the leg or arm
  • weakness or numbness on one side of the body

The healthcare professional giving the infusions can help lower the risk of a blood clot. They’ll do so by infusing Gamunex-C at the lowest dose and slowest rate needed for treating the condition. Before infusing each dose, they’ll also make sure you or your child is well hydrated.

What you can do

If you infuse Gamunex-C subcutaneously at home, follow the doctor’s instructions closely. They’ll provide guidelines that can help decrease the risk of blood clots.

If you think you or your child has symptoms of a blood clot that seem serious or life threatening, seek emergency medical attention. Call 911 or your local emergency number immediately.

Risk of worsened kidney function and acute kidney failure

Treatment with immune globulin medications can cause worsened kidney function. Gamunex-C is an immune globulin medication, but this side effect was rare in studies of the drug. These medications, including Gamunex-C, can also cause acute kidney failure as a side effect.

Worsened kidney function and acute kidney failure can happen to anyone treated with Gamunex-C. But some risk factors increase this risk as a side effect of Gamunex-C treatment, including:

Symptoms of kidney-related side effects caused by Gamunex-C include:

  • swelling in the ankles, feet, or legs
  • urinating a lower amount than usual
  • nausea
  • confusion
  • feeling weak or tired

The healthcare professional giving the infusions can help lower the risk of kidney-related side effects. They’ll do so by infusing Gamunex-C at the slowest rate possible. They’ll also test kidney function before and periodically throughout treatment with Gamunex-C. Before infusing each dose, they’ll also make sure you or your child is well hydrated.

What you can do

If you infuse Gamunex-C subcutaneously at home, follow the doctor’s instructions closely. They’ll provide guidelines that can help decrease the risk of worsened kidney function and acute kidney failure.

If you think you or your child has symptoms of worsening kidney function, let the doctor know right away. They can determine whether you or your child should stop using Gamunex-C and treat the kidney-related side effect.

You may be able to take certain actions that help make certain Gamunex-C side effects more manageable. If you have ongoing, worsening, or bothersome side effects, talk with the doctor or pharmacist. They can suggest tips for managing them or recommend other available treatment options for you or your child’s condition.

Nausea

Nausea was a common side effect reported in studies of Gamunex-C. It was reported in people receiving it for all FDA-approved uses.

Steps you can take to manage symptoms associated with this side effect include:

  • eating small amounts of plain foods every 1 or 2 hours, such as:
    • crackers, pretzels, toast, or ginger biscuits
    • chicken broth or chicken soup
    • applesauce or small amounts of banana
    • starchy foods, such as rice, potatoes, or noodles
  • drinking small amounts of liquid slowly (Be sure to stay hydrated.)
    • ginger or herbal tea
    • water, clear drinks, or clear juices
    • sparkling water or clear soda
    • sports beverages with electrolytes
  • avoiding foods that are:
    • spicy
    • very sweet
    • strong smelling
    • fatty, greasy, or fried

Abdominal pain

Abdominal pain was a common side effect reported in studies of Gamunex-C, especially in people receiving it for ITP.

Steps you can take to manage symptoms associated with this side effect include:

  • taking an over-the-counter (OTC) medication for stomach pain, bloating, or cramping, such as an antacid or antispasmodic (A pharmacist can guide you on the right medication for your symptoms.)
  • drinking teas, such as:
    • chamomile tea
    • ginger tea
    • lemon tea
    • peppermint tea
  • staying hydrated, especially drinking water
  • avoiding heavy meals and foods that might trigger pain
  • avoiding lying down for 30 minutes after eating

If the abdominal pain doesn’t go away or worsens after trying some of these tips, call the doctor. They may be able to prescribe medication that will help ease the pain.

Joint pain

Joint pain was a common side effect reported in studies of Gamunex-C, especially in people receiving it for PI and CIDP.

Steps you can take to manage symptoms associated with this side effect include:

  • using an OTC topical pain reliever
  • taking an OTC nonsteroidal anti-inflammatory drug (NSAID) to reduce swelling, inflammation, and pain
  • staying active but exercising moderately
  • stretching before exercising
  • getting a massage
  • taking a warm bath
  • getting enough rest

Your pharmacist can help you select a topical pain reliever and an NSAID.

If these tips don’t provide relief or the joint pain worsens, let the doctor know. They may be able to prescribe medication to reduce the pain or make other recommendations.

Consider the following important information before starting treatment with Gamunex-C.

Gamunex-C has boxed warnings. A boxed warning is the most serious warning from the FDA. For details, see the “Boxed warnings for Gamunex-C” section.

Other precautions

Before starting treatment with Gamunex-C, discuss your health history or your child’s health history with the doctor. Gamunex-C may not be the right medication if you or your child has certain medical conditions or other health factors. Be sure to talk with the doctor if any of the following apply:

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.