What is Immune Globulin (HIZENTRA): Uses, Dosage, Side Effects and More

Immune globulin subcutaneous, commonly known by the brand name HIZENTRA, is a purified antibody solution that you inject under your skin to strengthen your immune system. This medication contains protective antibodies collected from thousands of healthy blood donors, giving your body the infection-fighting power it needs when your immune system isn't working properly.

If you've been prescribed this medication, you likely have a condition where your body doesn't make enough antibodies on its own. Think of it as providing your immune system with backup soldiers when your natural defenses are running low.

What is Immune Globulin Used For?

Immune globulin subcutaneous treats primary immunodeficiency diseases, conditions where your immune system is born unable to produce enough protective antibodies. These aren't common conditions, but they can make you vulnerable to frequent, serious infections that your body struggles to fight off naturally.

Your doctor might prescribe this medication if you have conditions like common variable immunodeficiency, X-linked agammaglobulinemia, or severe combined immunodeficiency. These conditions sound complicated, but they all share one thing in common: your body needs help making the antibodies that keep infections at bay.

Sometimes doctors also use this medication for secondary immunodeficiencies, where another disease or treatment has weakened your immune system. This might happen if you're receiving certain cancer treatments or have conditions that affect your body's ability to produce antibodies.

How Does Immune Globulin Work?

Immune globulin works by giving your body ready-made antibodies that can immediately start fighting infections. These antibodies come from the pooled plasma of thousands of healthy donors, so they contain protection against many different germs and viruses.

When you inject this medication under your skin, these antibodies enter your bloodstream and circulate throughout your body. They act like your body's natural infection-fighting proteins, recognizing harmful bacteria and viruses and marking them for destruction.

This is considered a strong and effective treatment for immune deficiencies. Unlike some medications that just treat symptoms, immune globulin actually replaces what your body is missing, giving you real protection against infections.

How Should I Take Immune Globulin?

You'll inject immune globulin under the skin of your thigh, abdomen, upper arm, or lower back using a small needle and pump system. Most people inject it once a week, though your doctor will determine the exact schedule that works best for your condition.

Before each injection, let the medication warm to room temperature for about 30 minutes. Never heat it in a microwave or hot water, as this can damage the antibodies. You can eat normally before and after your injection, as food doesn't affect how well the medication works.

Your healthcare team will teach you how to inject the medication safely at home. The injection sites should be rotated each week to prevent irritation, and you should keep the injection sites at least one inch apart from each other and from any previous injection sites.

Always wash your hands thoroughly before preparing your injection, and use proper sterile technique to prevent introducing bacteria into your system. Store unopened vials in the refrigerator, but never freeze them.

How Long Should I Take Immune Globulin For?

Most people with primary immunodeficiency diseases need to take immune globulin for life, as these conditions don't cure themselves over time. Your immune system will continue to need this support to protect you from infections.

Your doctor will monitor your antibody levels through regular blood tests to make sure you're getting the right amount of protection. These tests help determine whether your dose needs to be adjusted or if the treatment schedule should be modified.

If you're taking immune globulin for a secondary immunodeficiency, you might be able to stop the treatment once your underlying condition improves or your other treatments are completed. Your doctor will guide you through this decision based on your specific situation.

What Are the Side Effects of Immune Globulin?

Most people tolerate immune globulin subcutaneous injections well, but you might experience some mild reactions, especially when you first start treatment. Your body is adjusting to receiving these new antibodies, so some initial responses are normal.

Common side effects that many people experience include mild swelling, redness, or tenderness at the injection site. These reactions usually appear within a few hours of injection and typically resolve within a day or two. You might also notice some itching or a small, firm bump where you injected the medication.

Here are the most frequent side effects you might encounter:

• Mild pain or discomfort at injection sites
• Redness or swelling under the skin
• Headache that develops within 24 hours of injection
• Mild fatigue or feeling generally unwell
• Nausea or mild stomach discomfort
• Muscle aches or joint pain

Most of these symptoms are mild and temporary, improving as your body gets used to the treatment. Many people find that side effects become less noticeable after the first few injections.

Less common but more serious side effects can occasionally occur, though they're much rarer with subcutaneous injections compared to intravenous immune globulin. These reactions require immediate medical attention if they develop.

Here are the more serious side effects to watch for:

• Severe allergic reactions with difficulty breathing or swallowing
• Widespread rash or hives appearing rapidly
• Severe headache with neck stiffness or sensitivity to light
• Chest pain or difficulty breathing
• Severe nausea with persistent vomiting
• Signs of kidney problems like decreased urination or swelling in legs

If you experience any of these serious symptoms, contact your healthcare provider immediately or seek emergency medical care. These reactions are uncommon, but they require prompt treatment when they occur.

Who Should Not Take Immune Globulin?

Immune globulin subcutaneous isn't safe for everyone, and certain medical conditions or circumstances make this treatment inappropriate or dangerous. Your doctor will carefully review your medical history before prescribing this medication.

You should not take immune globulin if you have a severe allergy to human antibodies or any component of the medication. People with IgA deficiency who have developed antibodies against IgA face a higher risk of severe allergic reactions and typically cannot use this treatment safely.

People with certain kidney problems need special consideration, as immune globulin can sometimes worsen kidney function. Your doctor will monitor your kidney function closely if you have any history of kidney disease or are taking medications that affect your kidneys.

Here are conditions that might make immune globulin unsuitable for you:

• Severe kidney disease or a history of kidney failure
• Active blood clotting disorders or recent blood clots
• Severe heart disease that makes fluid changes dangerous
• Previous severe allergic reactions to blood products
• Certain autoimmune conditions that could worsen with treatment

Your doctor will weigh the benefits against the risks for your specific situation and may recommend alternative treatments if immune globulin isn't appropriate for you.

Immune Globulin Brand Names

HIZENTRA is the most commonly prescribed brand of immune globulin for subcutaneous injection in the United States. This brand has been extensively studied and has a long track record of safety and effectiveness for treating primary immunodeficiency diseases.

Other subcutaneous immune globulin brands include GAMUNEX-C, GAMMAKED, and CUTAQUIG. Each brand has slightly different formulations, but they all contain the same basic ingredients and work in similar ways to boost your immune system.

Your doctor will choose the specific brand based on your individual needs, insurance coverage, and their clinical experience. All FDA-approved brands undergo rigorous testing to ensure they meet safety and effectiveness standards.

Immune Globulin Alternatives

Intravenous immune globulin (IVIG) is the main alternative to subcutaneous injections, delivered directly into your bloodstream through a vein. This option requires visits to a healthcare facility every 3-4 weeks and takes several hours to complete each infusion.

Some people prefer IVIG because it requires fewer treatment days per month, while others choose subcutaneous injections for the convenience of home treatment and more stable antibody levels. Your doctor will help you decide which option fits better with your lifestyle and medical needs.

For certain types of immunodeficiency, other treatments like bone marrow transplant or gene therapy might be considered, though these are typically reserved for the most severe cases. These treatments carry more risks but might offer the possibility of a cure rather than lifelong replacement therapy.

Is Immune Globulin Better Than IVIG?

Subcutaneous immune globulin and intravenous immune globulin are both effective treatments, but they each have distinct advantages depending on your situation and preferences. Neither is universally better than the other, as the best choice depends on your specific needs.

Subcutaneous injections offer more flexibility and convenience since you can do them at home on your own schedule. They also tend to cause fewer systemic side effects like headaches or flu-like symptoms, and they provide more stable antibody levels throughout the week.

IVIG might be preferable if you have difficulty with self-injection, need very high doses of antibodies, or have certain medical conditions that make subcutaneous administration challenging. Some people also prefer the less frequent treatment schedule despite the longer infusion times.

Your doctor will consider factors like your lifestyle, work schedule, comfort with self-injection, and how well your body responds to each type of treatment when making this recommendation.