Gammagard Liquid is a brand-name infusion prescribed for certain rare immune conditions. Gammagard Liquid contains the active ingredient immune globulin (human).

Specifically, the Food and Drug Administration (FDA) has approved Gammagard Liquid to treat:

For details about these conditions, see the “Gammagard Liquid uses” section.

Drug details

You’ll find key information about Gammagard Liquid here:

  • Drug class: immune globulin (also known as an immunoglobulin and commonly called an antibody)
  • Drug forms: solution that’s given as an intravenous (IV) or subcutaneous infusion by a healthcare professional
  • Generic or biosimilar available? no
  • Prescription required? yes
  • Controlled substance? no
  • Accelerated approval? no

Gammagard Liquid has boxed warnings. A boxed warning is the most serious warning from the FDA. For details, see the “Gammagard Liquid precautions” section.

Gammagard Liquid is available only as a brand-name biologic medication. It’s not currently available in a biosimilar form. A biosimilar medication is a drug that’s similar to a brand-name biologic drug (the reference drug).

Nonbiologics can have generics, which are exact copies of the active drug in the brand-name medication. However, it’s not possible to copy biologics exactly because they’re made from living cells. Instead, biologics can come in biosimilar forms.

Biosimilars are considered to be just as effective and safe as their reference drug. As with generics, biosimilars are often less expensive compared with brand-name medications. Learn more about cost and Gammagard Liquid in the “Cost and savings” section.

The Gammagard Liquid dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you’re using Gammagard Liquid to treat
  • your body weight in kilograms (kg)
  • the type of Gammagard Liquid infusion you receive
  • other medical conditions you may have, including exposure to measles

The following information describes dosages that are commonly used or recommended. However, your doctor will determine the best dosage to reach the desired immunoglobulin G (IgG) level for you. (An IgG is a type of antibody.) Your doctor will calculate your dose based on your body weight in kg. (For your reference, 1 kg is about 2.2 pounds.)

Drug form and strength

Gammagard Liquid comes as a solution containing 10% IgG, which is 100 milligrams of IgG antibodies per milliliter of solution (mg/mL).

Gammagard Liquid is given as an IV infusion (an injection into a vein given slowly over time). To treat primary immunodeficiency, Gammagard Liquid may be given as a subcutaneous infusion (an injection under your skin given slowly over time).

A healthcare professional will give your infusions in a doctor’s office, hospital, or infusion center, or even in your own home. However, you may be able to self-administer subcutaneous infusions of Gammagard Liquid at home after a nurse shows you how.

For more information about Gammagard Liquid administration, talk with your doctor. You can also refer to the Gammagard Liquid package insert or visit the manufacturer’s website.

Dosage for primary immunodeficiency (PI) in adults

Gammagard Liquid is prescribed as replacement therapy for PI in adults. The typically recommended dose is 300 to 600 milligrams per kilogram (mg/kg) of body weight. You’ll receive your prescribed dose by IV infusion once every 3 to 4 weeks.

Gammagard Liquid may also be prescribed for PI as a subcutaneous infusion, given once per week. If you’re switching from IV to subcutaneous infusions, your doctor will determine your dose.

Dosage for multifocal motor neuropathy (MMN) in adults

Gammagard Liquid is approved to treat MMN in adults. The typically recommended dose is 0.5 to 2.4 grams per kilogram (g/kg) of body weight. You’ll receive your prescribed dose by IV infusion once per month.

Dosage for chronic inflammatory demyelinating polyneuropathy (CIDP) in adults

Gammagard Liquid is also used to treat CIDP in adults. Doctors usually prescribe a loading dose to start, followed by maintenance (regular) doses. A loading dose is a larger amount of the drug at the beginning of treatment. This helps the drug start working right away. Your doctor may refer to the loading dose as the induction dose or induction phase.

The typical loading dose is 2 g/kg of body weight, given by IV infusion. You’ll receive this amount in divided doses over 2 to 5 days in a row.

The typical maintenance dose is 1 g/kg of body weight, given by IV infusion. You’ll receive this amount in divided doses over 1 to 4 days in a row, every 3 weeks.

Your first maintenance dose begins the day after you complete your loading dose. For example, if you receive your loading dose over a period of 2 days, your first maintenance dose would begin on day 3 of overall treatment.

If you have questions about your dosing schedule for Gammagard Liquid, talk with your doctor.

Children’s dosage

Gammagard Liquid is approved as a replacement therapy for PI in children ages 2 years and older.

The dosage of Gammagard Liquid in children is the same as the dosage in adults. For details, see “Dosage for primary immunodeficiency (PI) in adults.”

About Gammagard Liquid dosing

You’ll find information about key dosage issues here:

  • How long it takes to infuse Gammagard Liquid: Infusion times vary depending on certain factors, but a dose usually takes a few hours to infuse. Your doctor can tell you how long your infusion will take.
  • If you miss a dose: If you miss an infusion appointment, contact your doctor’s office to reschedule.
  • Length of use: Gammagard Liquid is meant to be a long-term treatment. If you and your doctor determine that the medication is safe and effective for you, you’ll likely receive it long term.
  • Length of time to work: How long Gammagard Liquid takes to work varies in people from days to weeks. For example, participants with CIDP who received the drug in this clinical trial reported improved functional ability (such as improved grip strength) within 25 days, on average.

Overdose

Using more than the recommended dosage of Gammagard Liquid can lead to serious side effects. These effects can include fluid overload and hyperviscosity (thick blood).

Fluid overload can cause rapid weight gain and swelling in the arms and legs. Hyperviscosity slows blood flow to vital organs and increases the risk of artery blockages. This can lead to serious problems, such as a heart attack or stroke.

What to do in case of overdose

If you think you’ve used too much of this drug, call your doctor. You can also call America’s Poison Centers at 800-222-1222 or use its online tool. However, if your symptoms are severe, call 911 or your local emergency number or go to the nearest emergency room right away.

Gammagard Liquid can cause mild or serious side effects. The following lists contain some of the key side effects that may occur during treatment with Gammagard Liquid. These lists do not include all possible side effects.

For more information about the possible side effects of Gammagard Liquid, talk with your doctor or pharmacist. They can give you tips on how to manage any side effects that may be concerning or bothersome. Side effects may differ slightly between people depending on the condition you’re using Gammagard Liquid to treat.

Note: After the FDA approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medications safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect during treatment with Gammagard Liquid and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Mild side effects

Here is a partial list of mild side effects of Gammagard Liquid. To learn about other mild side effects, talk with your doctor or pharmacist, or view the drug’s prescribing information.

Mild side effects of Gammagard Liquid can include:

Most of these side effects may go away within a few days to a couple of weeks. However, if they become more severe or don’t go away, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Gammagard Liquid aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency phone number if your symptoms feel life threatening or you think you’re having a medical emergency.

Serious side effects can include:

Your doctor will monitor you for serious side effects. They may order certain blood tests throughout your treatment with Gammagard Liquid. This helps your doctor identify problems before they become serious.

* Gammagard Liquid has a boxed warning for this side effect. This is the most serious warning from the FDA. To learn more, see the “Gammagard Liquid precautions” section.

Side effects in children

Gammagard Liquid is approved for children ages 2 years and over with primary immunodeficiency (PI). The side effects reported in children receiving this medication in clinical trials are similar to those reported in adults. For details, see the “Mild side effects” and “Serious side effects” sections.

Allergic reaction

For some people, Gammagard Liquid can cause an allergic reaction. But it’s not clear whether this side effect occurred in the drug’s studies.

In general, symptoms of an allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep using the medication.

For severe allergic reaction symptoms, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Gammagard Liquid, your doctor may recommend a different medication instead.

Gammagard Liquid is FDA approved to treat three rare conditions associated with your immune system. To learn how Gammagard Liquid performed in clinical trials, see the drug’s prescribing information.

Gammagard Liquid for primary immunodeficiency (PI)

With immunodeficiency, one or more parts of your immune system don’t work right. A primary immunodeficiency is one that you’re born with. There are hundreds of different PIs that range in severity. Examples include:

Your immune system makes proteins called immunoglobulins (commonly known as antibodies) to protect you against infections and other diseases. These antibodies target specific bacteria, viruses, and other microbes that cause infection. People with a PI don’t have enough antibodies to protect them. They may develop severe, unusual, and chronic (long-lasting) infections.

Gammagard Liquid is approved as replacement therapy for PI in people ages 2 years and older. Gammagard Liquid contains antibodies that target a wide range of bacteria and viruses. This helps reduce the risk of infection in people with PI.

Gammagard Liquid for multifocal motor neuropathy (MMN)

MMN is a rare condition that causes muscle weakness. It often affects the upper body more than the lower body. People with MMN have reduced strength that may limit their ability to carry out everyday activities, such as getting dressed.

MMN is thought to be caused by antibodies your immune system makes against substances called gangliosides (anti-GM1 antibodies). GM1 is part of the protective layer (myelin) around neurons (also known as nerves or nerve cells). Anti-GM1 antibodies reduce signals between motor neurons (cells that control voluntary muscle movement, such as raising your hand) and the muscles they supply.

Gammagard Liquid is approved to treat MMN in adults. Researchers don’t know exactly how Gammagard Liquid works to treat MMN. For more information, see “How Gammagard Liquid works.”

Gammagard Liquid for chronic inflammatory demyelinating polyneuropathy (CIDP)

Gammagard Liquid is also approved to treat CIDP in adults. CIDP is thought to be an autoimmune disorder. With an autoimmune disorder, your immune system mistakenly makes antibodies against your own healthy tissues.

With CIDP, antibodies target the protective myelin sheath of neurons. These antibodies decrease the ability of neurons to relay signals between each other. CIDP also causes inflammation. CIDP symptoms may include numbness, tingling, and/or loss of sensation in your hands and/or feet.

It’s not clear how Gammagard Liquid works to treat CIDP. To learn more, see “How Gammagard Liquid works.”

Gammagard Liquid and children

Gammagard Liquid is approved to treat PI in children ages 2 years and older. For details about this condition, see “Gammagard Liquid for primary immunodeficiency (PI)” near the beginning of this section.

An interaction is when one substance causes another substance to have a different effect than expected. This can occur when a drug is taken with other medications, supplements, foods, or even certain health conditions, potentially affecting the effectiveness or safety of the medication.

Vaccine interaction

Gammagard Liquid can interact with live vaccines, such as the chickenpox vaccine (Varivax) or measles, mumps, and rubella (MMR). Before starting Gammagard Liquid, ask your doctor what vaccines you may need.

It’s not clear whether Gammagard Liquid interacts with medications, supplements, or foods. The manufacturer did not list any interactions (besides live vaccines) in the drug’s prescribing information.

Before starting treatment, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

Alcohol interaction

Alcohol is not known to interact with Gammagard Liquid. It’s likely safe to consume alcohol while using Gammagard Liquid. If you have questions about how much alcohol is safe to drink while receiving Gammagard Liquid, talk with your doctor or pharmacist.

As with all medications, the cost of Gammagard Liquid can vary. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Gammagard Liquid prices may also depend on the cost of the visit to your healthcare professional to receive doses of Gammagard Liquid. (For details about this, see the “Gammagard Liquid dosage” section.)

Financial and insurance assistance: If you need financial support to pay for Gammagard Liquid or help understanding your insurance coverage, help is available.

A program called Takeda Patient Support Co-Pay Assistance Program is available for Gammagard Liquid. For more information and to find out if you’re eligible for support, call 866-861-1750 or visit the program website.

Generic or biosimilar version: Gammagard Liquid is not available in a biosimilar form. A biosimilar is a close copy of the active ingredient in a brand-name biologic medication. Biosimilars tend to cost less than brand-name drugs. For more information, see “Gammagard Liquid generic or biosimilar” earlier in the article.

Other drugs are available that can treat your condition. Some may be a better fit for you than others. If you’re interested in finding an alternative to Gammagard Liquid, talk with your doctor. They can tell you about other medications that may work well for you.

For treating primary immunodeficiency, the following drugs are similar to Gammagard Liquid:

  • immune globulin intravenous, human IgA (Gammagard S/D)
  • immune globulin intravenous, human (Gammaplex, Privigen, others)
  • immune globulin intravenous, human-stwk (Alyglo)
  • immune globulin intravenous, human-dira (Yimmugo)
  • immune globulin intravenous, human-ifas (Panzyga)
  • immune globulin subcutaneous, human–klhw (Xembify)
  • immune globulin subcutaneous, human (Cuvitru, Hizentra)
  • immune globulin injection, human (Gammaked)

For treating chronic inflammatory demyelinating polyneuropathy, the following drugs are similar to Gammagard Liquid:

  • immune globulin intravenous, human (Privigen)
  • immune globulin intravenous, human-ifas (Panzyga)
  • immune globulin subcutaneous, human (Hizentra)
  • immune globulin injection, human (Gammaked)

The FDA has not approved any medications similar to Gammagard Liquid for treating multifocal motor neuropathy.

If you can become pregnant, consider the following information about pregnancy, fertility, birth control, and breastfeeding.

Gammagard Liquid and pregnancy

It’s not known whether Gammagard Liquid should be used during pregnancy. The effects of the drug on a developing fetus have not been studied.

If you’re planning a pregnancy or can become pregnant, talk with your doctor about potential treatments for your condition during pregnancy. Together, you can consider the risks and benefits of your treatment options and decide whether or not you should receive Gammagard Liquid during pregnancy.

Gammagard Liquid and fertility

It’s not known whether Gammagard Liquid has an affect on fertility (the ability to conceive). The effect of the drug on fertility have not been studied.

Gammagard Liquid and birth control

It’s not known whether Gammagard Liquid is safe to use during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control options while you’re using Gammagard Liquid.

Gammagard Liquid and breastfeeding

It’s not known whether Gammagard Liquid should be used while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before using this medication.

Gammagard Liquid works in a couple different ways.

First, it increases the level of IgG antibodies in your body. IgG antibodies protect you from infections. With primary immunodeficiency, you don’t have enough IgG antibodies to guard you against bacteria, viruses, and other microbes that cause infections. Gammagard Liquid contains IgG antibodies against many different bacteria and viruses, which helps prevent the infections they cause. Gammagard Liquid lowers your risk of infection.

Second, the IgG and other antibodies in Gammagard Liquid interact with cells and other factors in your immune system. The exact way these interactions work to treat chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy is not completely understood. Both of these conditions cause inflammation that damages certain nerve cells.

It’s thought that interactions between Gammagard Liquid and your immune system decrease inflammation. By lowering inflammation, Gammagard Liquid protects nerves and helps reduce symptoms of neuropathy.

If you’d like to know more about Gammagard Liquid’s mechanism of action (how it works), talk with your doctor.

Here are answers to some frequently asked questions about Gammagard Liquid.

Is Gammagard Liquid a chemo drug?

No, Gammagard Liquid is made of IgG antibodies isolated from donated human plasma (the main part of blood). Chemotherapy drugs damage and kill cells that grow fast, including cancer cells.

The plasma used to make Gammagard Liquid is screened and treated for certain harmful substances to ensure its safety.

If you’d like to know more about Gammagard Liquid, talk with your doctor. You can also view the drug’s prescribing information or visit the manufacturer’s website for details.

Can I switch from IV to subcutaneous infusions of Gammagard Liquid?

Yes, generally. Before switching, your doctor will check the level of IgG antibodies in your blood to determine the right dosage of Gammagard Liquid. Typically, you’ll receive your first subcutaneous infusion approximately 1 week after your last IV infusion.

For more information about switching from Gammagard Liquid IV to subcutaneous infusions, talk with your doctor.

Take care to consider the following important information about Gammagard Liquid.

FDA warnings

This drug has boxed warnings. A boxed warning is the most serious warning from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

Risk of thrombosis (blood clot): Treatment with immunoglobulin medications, including Gammagard Liquid, may cause blood clots, such as a deep vein thrombosis. Certain factors and conditions can increase the risk of blood clots, such as:

Note that thrombosis can occur in people without risk factors.

Blood clots can develop anywhere in the body, including in the heart, brain, or lungs, and become life threatening in some cases. Due to this risk, be sure to discuss your full medical history with your doctor before starting Gammagard Liquid. You’ll also have certain blood tests. If you have risk factors for blood clots, your doctor will adjust your Gammagard Liquid dose and infusion time.

During treatment with Gammagard Liquid, be aware of and watch for the following symptoms of blood clots:

  • pain, warmth, and/or swelling of your arm or leg
  • redness or other change in color of your arm or leg
  • chest pain
  • shortness of breath
  • rapid pulse
  • numbness or weakness on one side of your body

If you notice any of these symptoms, call your doctor right away. If your symptoms are serious or you think you’re having a medical emergency, call 911 or a local emergency number.

Risk of kidney disease: People with kidney problems who receive intravenous immunoglobulin (IVIg) products have an increased risk of kidney disease, kidney failure, and even death. (Gammagard Liquid is an IVIg product.) This risk also affects people who have risk factors for kidney problems, such as:

  • having diabetes
  • being over age 65 years
  • taking certain medications

Due to this risk, your doctor will order certain tests to check your kidney function before and during treatment with Gammagard Liquid. If these tests show decreased kidney function, your doctor may have you stop treatment with Gammagard Liquid.

If you have questions about these warnings or your risk factors, talk with your doctor for more information.

Other precautions

Before receiving Gammagard Liquid, discuss your health history with your doctor. Gammagard Liquid may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • IgA deficiency with antibodies to IgA (a type of immunoglobulin)
  • kidney problems
  • any condition that increases your risk of blood clots
  • history of blood clots
  • heart disease risk factors, such as high cholesterol
  • previous allergic reaction to this or a similar drug
  • pregnancy
  • breastfeeding

Note: For more information about the potential negative effects of Gammagard Liquid, see the “Gammagard Liquid side effects” section.

Disclaimer: Medical News Today 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.