What is Rituximab: Uses, Dosage, Side Effects and More

Rituximab is a prescription medication that helps treat certain types of cancer and autoimmune diseases by targeting specific cells in your immune system. This powerful medicine works by blocking a protein called CD20 that's found on certain white blood cells, helping your body fight diseases more effectively.

If your doctor has recommended rituximab, you might have questions about how it works and what to expect. This medication has helped many people manage serious conditions, and understanding more about it can help you feel more prepared for your treatment journey.

What is Rituximab?

Rituximab is a type of targeted therapy called a monoclonal antibody. Think of it as a specially designed key that fits into a specific lock on certain cells in your body. This medication is given through an IV infusion, which means it's delivered directly into your bloodstream through a vein.

The medication belongs to a class of drugs called immunosuppressants. It works by temporarily reducing the activity of certain parts of your immune system. While this might sound concerning, this targeted approach helps treat conditions where your immune system is either overactive or where certain immune cells have become cancerous.

Rituximab is considered a strong medication that requires careful monitoring by your healthcare team. Your doctor will closely track how your body responds to ensure you're getting the best possible results while minimizing any risks.

What is Rituximab Used For?

Rituximab treats several serious conditions that affect your blood, lymph nodes, and immune system. Your doctor may prescribe it for both cancer-related and autoimmune conditions where your body's defense system needs targeted help.

The most common conditions treated with rituximab include various types of blood cancers. These conditions occur when certain white blood cells grow uncontrollably or don't function properly.

• Non-Hodgkin's lymphoma, a cancer affecting your lymphatic system
• Chronic lymphocytic leukemia, a slow-growing blood cancer
• Diffuse large B-cell lymphoma, an aggressive form of lymphoma
• Follicular lymphoma, a type that tends to grow slowly

Rituximab also helps treat autoimmune conditions where your immune system mistakenly attacks healthy parts of your body. For these conditions, the medication helps calm down the overactive immune response.

• Rheumatoid arthritis when other treatments haven't worked well enough
• Granulomatosis with polyangiitis, a rare condition affecting blood vessels
• Microscopic polyangiitis, another rare blood vessel condition
• Pemphigus vulgaris, a serious skin blistering condition

In some cases, doctors may prescribe rituximab for other conditions not listed here. This is called off-label use, and your doctor will explain why this medication might be right for your specific situation.

How Does Rituximab Work?

Rituximab works by attaching to a specific protein called CD20 that sits on the surface of certain white blood cells called B-cells. Once attached, it signals your immune system to destroy these cells, which helps treat your condition.

For cancer treatment, rituximab targets the cancerous B-cells that are growing out of control. By marking these cells for destruction, it helps slow down or stop the cancer's growth. The medication works alongside your body's natural defenses to fight the disease more effectively.

When treating autoimmune conditions, rituximab reduces the number of B-cells that are producing antibodies attacking your healthy tissues. This gives your body a chance to reset and reduces the inflammation and damage caused by the overactive immune response.

The effects of rituximab can last for several months after your treatment ends. Your B-cell count will gradually return to normal levels over time, typically within 6 to 12 months, though this varies from person to person.

How Should I Take Rituximab?

Rituximab is always given as an intravenous infusion in a hospital or clinic setting. You cannot take this medication at home, as it requires careful monitoring by trained healthcare professionals throughout the process.

Before your infusion, your healthcare team will give you pre-medications to help prevent allergic reactions. These typically include antihistamines, acetaminophen, and sometimes corticosteroids. Taking these medications about 30 to 60 minutes before your rituximab infusion helps your body tolerate the treatment better.

The infusion itself usually takes several hours. Your first dose is typically given more slowly to watch for any reactions, often starting at a rate of 50 mg per hour. If you tolerate it well, the rate may be increased gradually. Subsequent infusions may be given faster if you've had no serious reactions.

During your infusion, you'll be monitored closely for any signs of allergic reactions or side effects. Your blood pressure, heart rate, and temperature will be checked regularly. You can usually read, use your phone, or rest during the treatment.

You don't need to fast before your rituximab infusion, and you can eat normally on treatment days. However, it's good to stay well-hydrated by drinking plenty of water before and after your treatment.

How Long Should I Take Rituximab For?

The duration of rituximab treatment depends on your specific condition and how well you respond to the medication. Your doctor will create a treatment plan tailored to your needs, which may involve several infusions over weeks or months.

For most lymphomas, you'll typically receive rituximab once a week for 4 weeks, or once every 3 weeks for 6 to 8 cycles. Some people may need maintenance therapy, which involves receiving rituximab every few months for up to 2 years to help prevent the cancer from returning.

For autoimmune conditions like rheumatoid arthritis, the usual schedule involves two infusions given 2 weeks apart. You may need repeat courses every 6 months or longer, depending on how your symptoms respond and how long the benefits last.

Your doctor will monitor your response through regular blood tests and imaging studies. Based on these results and how you're feeling, they may adjust your treatment schedule or recommend stopping the medication if you've achieved good disease control.

What Are the Side Effects of Rituximab?

Like all powerful medications, rituximab can cause side effects, though many people tolerate it well with proper monitoring and support. Understanding what to expect can help you feel more prepared and know when to contact your healthcare team.

The most common side effects occur during or shortly after your infusion and are usually manageable with pre-medications and careful monitoring.

• Infusion reactions including fever, chills, nausea, or headache
• Fatigue that may last for several days after treatment
• Low blood pressure or dizziness during infusion
• Muscle aches and joint pain
• Skin rash or itching
• Throat irritation or cough

These immediate reactions are usually mild and improve quickly with treatment. Your healthcare team is well-prepared to manage them if they occur.

Some side effects may develop days or weeks after your treatment as your immune system adjusts to the medication.

• Increased risk of infections due to lowered immune function
• Low white blood cell count that may last several months
• Temporary hair thinning or changes in hair texture
• Digestive issues like nausea, diarrhea, or stomach pain
• Sleep problems or mood changes

More serious side effects are less common but require immediate medical attention. Your doctor will discuss these risks with you and explain warning signs to watch for.

• Severe infections that may be harder to fight off
• Reactivation of hepatitis B in people with previous exposure
• Progressive multifocal leukoencephalopathy, a rare brain infection
• Severe skin reactions or tumor lysis syndrome
• Heart problems in people with existing heart conditions

These serious complications are rare, and your healthcare team will monitor you carefully to catch any problems early. Regular blood tests and check-ups help ensure your treatment remains as safe as possible.

Who Should Not Take Rituximab?

Rituximab isn't suitable for everyone, and your doctor will carefully review your medical history to determine if it's safe for you. Certain conditions or situations may make this medication too risky or less effective.

You should not receive rituximab if you have an active, serious infection that your body is currently fighting. The medication suppresses your immune system, which could make infections worse or harder to treat. Your doctor will want to clear up any infections before starting treatment.

People with certain viral infections need special consideration before receiving rituximab. If you have hepatitis B, even if it's inactive, the medication could cause the virus to become active again and damage your liver. Your doctor will test for hepatitis B and may give you antiviral medications if needed.

Rituximab may not be appropriate if you have severe heart problems, especially congestive heart failure or a history of serious heart rhythm problems. The medication can sometimes affect heart function, so your doctor will evaluate your heart health carefully.

Pregnancy and breastfeeding require special consideration. Rituximab can cross the placenta and may affect a developing baby's immune system. If you're pregnant, planning to become pregnant, or breastfeeding, discuss these concerns with your doctor to weigh the benefits and risks.

People with certain immune system disorders may need modified treatment plans. Your doctor will consider your overall health status and any other medications you're taking to determine the safest approach.

Rituximab Brand Names

Rituximab is available under several brand names, with the original version being Rituxan. This was the first rituximab medication approved and has been used safely for many years in treating various conditions.

Several biosimilar versions of rituximab are now available, including Ruxience, Truxima, and Riabni. These medications contain essentially the same active ingredient as the original but may be produced by different manufacturers. Your doctor or pharmacist can explain which version you're receiving.

Biosimilars undergo rigorous testing to ensure they work just as well as the original medication. They offer the same benefits and have similar side effect profiles, often at a lower cost. Your insurance may prefer certain brands, and your healthcare team will work with you to ensure you receive the most appropriate option.

Regardless of which brand you receive, the medication will be prepared and given in the same way. Your healthcare team will monitor you carefully no matter which version of rituximab you're getting.

Rituximab Alternatives

Several other medications can treat similar conditions to rituximab, though the best choice depends on your specific diagnosis and individual circumstances. Your doctor will consider various factors when selecting the most appropriate treatment for you.

For blood cancers, other targeted therapies may be options depending on your specific type of lymphoma or leukemia. These include medications like obinutuzumab, ibrutinib, or venetoclax. Each works differently and may be better suited for certain subtypes of cancer.

For autoimmune conditions like rheumatoid arthritis, alternatives include other biologics such as adalimumab, etanercept, or abatacept. Traditional disease-modifying drugs like methotrexate or sulfasalazine might also be considered, depending on your disease severity and treatment history.

Chemotherapy combinations remain important treatments for many blood cancers. Your doctor might recommend regimens like CHOP, CVP, or other combinations that include different types of cancer-fighting drugs. These may be used alone or in combination with rituximab.

The choice between rituximab and alternatives depends on factors like your specific diagnosis, previous treatments, overall health, and personal preferences. Your oncologist or rheumatologist will help you understand the pros and cons of each option.

Is Rituximab Better Than Other Similar Medications?

Rituximab has been extensively studied and proven effective for many conditions, but whether it's "better" than other medications depends on your specific situation. Each person's disease and body responds differently to various treatments.

For many types of non-Hodgkin's lymphoma, rituximab has become a standard part of treatment because it significantly improves outcomes when added to chemotherapy. Studies have shown that people receiving rituximab along with chemotherapy often live longer and have better disease control than those receiving chemotherapy alone.

Compared to newer targeted therapies, rituximab has the advantage of longer experience and established effectiveness. However, some newer medications might work better for specific subtypes of cancer or for people who don't respond well to rituximab.

For autoimmune conditions, rituximab is often reserved for people who haven't responded well to other treatments. While it can be very effective, it's usually not the first choice due to its powerful effects on the immune system. Other medications with fewer immune-suppressing effects might be tried first.

Your doctor will consider your individual factors, including your specific diagnosis, previous treatments, overall health, and personal preferences when deciding between rituximab and other options. The "best" medication is the one that works well for you with manageable side effects.