- What is rituximab? How does it work (mechanism of action)?
- What are the uses for rituximab?
- What are the side effects of rituximab?
- What is the dosage for rituximab?
- Which drugs or supplements interact with rituximab?
- Is rituximab safe to take if I'm pregnant or breastfeeding?
- What else should I know about rituximab?
What is rituximab? How does it work (mechanism of action)?
- Rituximab is an intravenous drug that is used to treat rheumatoid arthritis and B-cell non-Hodgkin's lymphoma. It belongs to a class of drugs called monoclonal antibodies. Other monoclonal antibodies include trastuzumab (Herceptin) and gemtuzumab ozogamicin (Mylotarg). Tumor cells (like most normal cells) have receptors on their surfaces. Many kinds of chemicals, proteins, etc., on the outside of the cell can attach to these receptors. When they do, they can cause changes to occur within the cells. One receptor, present in more than 90% of B-cell non-Hodgkin's lymphomas, is called CD20. Molecules that attach to CD20 can affect the growth and development of the tumor cells and, sometimes, the production of new tumor cells. Rituximab is a man-made antibody that was developed using cloning and recombinant DNA technology from human and murine (mice or rat) genes. Rituximab is thought to attach to the CD20 receptor and cause the tumor cells to disintegrate (lyse). In some non-Hodgkin's lymphomas, it also prevents the production of more tumor cells.
- In the treatment of rheumatoid arthritis, rituximab is used when other biologic medications (TNF-blockers, such as infliximab, [Remicade] etanercept [Enbrel], or adalimumab [Humira]) have failed to be effective. The effectiveness of rituximab is a result of it temporarily depleting the number of B-cells, cells of the immune system that are important in promoting inflammation in rheumatoid arthritis.
- Rituximab was approved by the FDA in 1997.
What are the uses for rituximab?
Rituximab is used for the treatment of:
- Non-Hodgkin's B-cell lymphomas that have CD20 receptors on their surface. It is used when lymphomas recur following other types of therapy or are unresponsive to other types of therapy.
- Chronic lymphocytic leukemia
- Granulomatosis with polyangiitis
- Microscopic polyangiitis
Rituximab also is combined with methotrexate (Rheumatrex, Trexall) to treat rheumatoid arthritis in patients who have failed other biologic medications, such as infliximab (Remicade), etanercept (Enbrel), or adalimumab (Humira).
What are the side effects of rituximab?
- The most common side effect of rituximab is a constellation of symptoms (fever, rigors and chills) that occur during administration of the first dose of drug. More than 80% of patients experience these side effects, and it is severe in 4-7 out of every 10,000 patients. The side effects appear only 40% of the time with the second dose of drug and become less frequent with the last two doses.
- Other common side effects related to rituximab are:
- After rituximab is administered, large numbers of tumor cells are immediately destroyed (lysed) and eliminated from the body. In 4-5 out of every 10,000 patients the products from the dead cells cannot be eliminated quickly enough and a syndrome called tumor lysis syndrome occurs. This is characterized by a rapid decline in kidney function and a sudden accumulation or decrease in minerals such as potassium, calcium and phosphate to dangerous levels. Tumor lysis syndrome occurs when the size of the tumor or the number of tumor cells circulating in the blood is large, usually within 12-24 hours after the first dose of rituximab.
- Irregular heart rhythms and infection are two other rarely-occurring side effects that may be severe. The irregular heart rhythm usually begins soon after the administration of the drug, while infection may develop from 30 days to 11 months after the end of therapy. Severe decreases in red or white blood cells and platelets (thrombocytopenia) may occur rarely with rituximab therapy. Rituximab suppresses the immune system. Therefore, serious fungal, bacterial, and new or reactivated viral infections (for example, hepatitis B or C, shingles) can occur during or after treatment with rituximab. Generally, rituximab is avoided in the presence of active, significant infections. Rituximab may also cause severe skin reactions within 1 to 13 weeks after treatment is started. Rituximab therapy is not recommended if there is an allergy to mice or rats since rituximab is made in mice or rats and may contain minute amounts of rat or mice proteins that can lead to severe allergic reactions.
What is the dosage for rituximab?
- Rituximab is administered by intravenous infusion. Patients should receive acetaminophen (Tylenol) and an antihistamine prior to the infusion to reduce the severity of infusion reactions.
- Patients with rheumatoid arthritis also should receive methylprednisolone (Medrol, Depo-Medrol) 100 mg or a similar drug 30 minutes prior to the infusion to reduce the severity of infusion reactions.
- Non-Hodgkin's B-cell lymphomas: 375 mg/m2 weekly for 4 to 8 weeks or longer.
- Chronic lymphocytic leukemia: 375 mg/m2 for the first cycle then 500 mg/m2 every 28 days for cycles 2 to 6.
- Granulomatosis with polyangiitis or microscopic polyangiitis: 375 mg/m2
- Rheumatoid arthritis: Two 1000 mg infusions are administered two weeks apart and then are repeated every 16 to 24 weeks.
Which drugs or supplements interact with rituximab?
Quick GuidePancreatic Cancer Symptoms, Causes, and Treatment
Is rituximab safe to take if I'm pregnant or breastfeeding?
- There are not enough studies to draw conclusions about the safety of rituximab in pregnant women. Contraceptive methods are recommended if rituximab is used in women of childbearing age and for up to 12 months after stopping therapy.
- Since rituximab is an antibody that can be secreted into breast milk and absorbed by the infant, it has the potential for harming nursing infants. Women who are breastfeeding should avoid rituximab therapy and not begin nursing until rituximab is no longer present in the blood.
What else should I know about rituximab?
Rituximab is abailable as:
- Powder for intravenous injection: 100, 200, 500, 1000, and 2000 mg)
- Tabletss: 25, 50 mg.
Powder and tablets should be stored at room temperature, 15 C - 30 C (59 F - 86 F). Solutions prepared with bacteriostatic water are usable up to 24 hours if stored at room temperature and up to 6 days if stored in the refrigerator.
Rituximab is not available in generic form. You need a prescription for this drug.Rituxan is the brand name for rituximab in the US.
Rituximab (Rituxan) is a medication prescribed for the treatment of non-Hodgkin's B-cell lymphomas, chronic lymphocytic leukemia, granulomatosis with polyangiitis, and microscopic polyangiitis.
Rituxan is combined with methotrexate (Trexall) to treat rheumatoid arthritis. Side effects, drug interactions, dosage, and pregnancy safety should be reviewed prior to taking this medication.
Multimedia: Slideshows, Images & Quizzes
Top 10 Cancers Quiz
Take this quiz to learn the causes of cancer. Get the facts about the causes, symptoms, and treatments for the world's most...
Rheumatoid Arthritis Quiz: What is Rheumatoid Arthritis?
How is rheumatoid arthritis different from other forms of arthritis, such as osteoarthritis and gout? Take the Rheumatoid...
Systemic Lupus Erythematosus Quiz: Test Your SLE IQ
This Lupus Quiz covers causes, signs, symptoms, facts, and treatments for this inflammatory autoimmune disease....
Picture of Systemic Lupus Erythematosus 1
A chronic inflammatory condition caused by an autoimmune disease. See a picture of Systemic Lupus Erythematosus (SLE) and learn...
Picture of Lupus
A chronic inflammatory condition caused by an autoimmune disease. See a picture of Lupus Rash and learn more about the health...
Picture of Systemic Lupus Erythematosus 2
Erythematous, edematous plaques appear in a "butterfly" distribution on the face. See a picture of Systemic Lupus Erythematosus...
Picture of Acute Systemic Lupus
Acute systemic lupus erythematosus. See a picture of Acute Systemic Lupus and learn more about the health topic....
Understanding Cancer: Metastasis, Stages of Cancer, and More
Learn the basics about cancer including types, causes, how it spreads, symptoms and signs, stages and treatment options. Read...
Rheumatoid Arthritis (RA) Symptoms & Treatment
What is rheumatoid arthritis (RA)? Learn about juvenile rheumatoid arthritis. Discover rheumatoid arthritis (RA) symptoms,...
Signs of Cancer in Women: Symptoms You Can't Ignore
Cancer symptoms can surprise women if they don't know what to watch out for. 15 cancer symptoms women ignore such as weight loss,...
Lupus Symptoms, Rash, and Treatment
What is Lupus? Learn about lupus symptoms like butterfly rash, joint pain and fatigue. Find causes, diagnosis, and treatments for...
Rheumatoid Arthritis (RA) Exercises Slideshow: Joint-Friendly Fitness Routines
Regular exercise boosts fitness and helps reverse joint stiffness for people with rheumatoid arthritis (RA). Our experts offer...
Cancer-Fighting Foods in Pictures: Resveratrol, Green Tea, and More
Experts have praised certain foods for their ability to reduce cancer risks. Learn which foods and eating strategies may help...
Signs of Cancer in Men: Could it Be Cancer?
See pictures of which 15 cancer symptoms men ignore such as skin changes, difficulty swallowing, rapid weight loss, a breast...
Famous Faces With Rheumatoid Arthritis
Learn more about the famous faces of rheumatoid arthritis such as Lucille Ball, Glenn Frey, and more....
Cancer: Guide to Leukemia
Learn about the common types and stages of leukemia, who gets it, symptoms, tests, treatments, and more. People with blood cancer...
Related Disease Conditions
Pain Management and Rheumatoid Arthritis
Second Source article from WebMD...
Second Source article from Government...
16 Early Symptoms and Signs of Rheumatoid Arthritis (RA)
Early RA symptoms and signs vary differently from person to person. The most common body parts that are initially affected by RA...
Cancer is a disease caused by an abnormal growth of cells, also called malignancy. It is a group of 100 different diseases, and...
Rheumatoid Arthritis (RA)
Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints, the tissue around the joints,...
Sjögren's syndrome is an autoimmune disease involving the abnormal production of extra antibodies that attack the glands and...
Non-Hodgkin's lymphoma is cancer of the lymphatic system, a vital part of the body's immune system. Symptoms and signs include...
Myasthenia gravis, a chronic autoimmune neuromuscular disease. Varying degrees of weakness of the voluntary muscles of the body...
Lupus (Systemic Lupus Erythematosus or SLE)
Systemic lupus erythematosus is a condition characterized by chronic inflammation of body tissues caused by autoimmune disease....
Mantle Cell Lymphoma (MCL)
Mantle cell lymphoma (MCL) is a rare form of non-Hodgkin's lymphoma. It is not known what causes MCL. MCL signs and symptoms...
Rheumatoid Arthritis vs. Fibromyalgia
Though rheumatoid arthritis (RA) and fibromyalgia have similar symptoms, RA is an autoimmune disease and fibromyalgia is a...
Granulomatosis with Polyangiitis
Granulomatosis with polyangiitis is a condition that usually affects young or middle-aged adults, is an inflammation of the...
Rheumatology is the study of rheumatic diseases and conditions. Rheumatologists are internal medicine physicians who treat these...
Stiff-Person syndrome is a neurological disorder associated with features of an autoimmune disease. Signs and symptoms of...
Juvenile Idiopathic Arthritis (Juvenile Rheumatoid Arthritis)
Juvenile idiopathic arthritis (juvenile rheumatoid arthritis or JRA) annually affects one child in every thousand. There are six...
Castleman Disease is a group of related conditions. It is a rare disease with an unknown prevalence. Signs and symptoms of...
Treatment & Diagnosis
- Rheumatoid Arthritis FAQs
- Systemic Lupus Erythematosus FAQs
- Cancer FAQs
- Medication Disposal
- Dangers of Mixing Medications
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- National Arthritis Meeting 2003
- Rheumatoid Arthritis Perspectives:2003 National Meeting
- Arthritis Drugs and New Meds: 2004 Perspectives
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
Prevention & Wellness
- Truxima Approved as First Biosimilar to Non-Hodgkin's Lymphoma Drug
- Adding Drug to Standard Care May Prolong Lymphoma Survival
- Study Suggests Causes for Lupus' Impact on Immune System
- 2 Drugs Show Promise Against Blood Cancers
- New Drug Combo Might Help Older, Sicker Patients With Leukemia
- New Strategy Helps Young Lymphoma Patients Avoid Radiation Treatment
- Newer Rheumatoid Arthritis Drugs Don't Raise Cancer Risk: Study
- Newer Drugs Help RA Patients Live Longer
- 'Rediscovered' Lymphoma Drug Helps Double Survival: Study
- More Aggressive Chemo May Help Younger Lymphoma Patients: Study
- Cancer Drug May Also Treat Chronic Fatigue Syndrome
- Two-Drug Combo May Help Hard-to-Treat Leukemia
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.