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What is Rituxan?

Lupus is a complex condition requiring doctors to often think outside the box regarding treatment and symptom management. There are different categories of medications and therapies to treat lupus, and this blog will address a medication that has become increasingly popular in its use to treat various lupus complications. It is a medication that sometimes can feel scary to read or hear about. We hope this information will help alleviate the fear of the unknown regarding Rituxan for treating lupus.

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What is it?

Rituximab (Rituxan) is a commonly used biologic drug (sometimes called a “biological agent” in fancy medical terms) that is produced by a living system, like a bacteria, animal or plant cell. It is in a separate category from other drug agents or medications that are NOT from organic material, like HCQ or prednisone (which are made in a lab).

Lupus is a disease where the body’s own natural defense system (i.e., the immune system) is overactive, causing it to produce autoantibodies. This medication helps suppress overactive cells that attack healthy cells by mistake, which may cause inflammation and lead to pain, fatigue, and a whole host of problems and unwanted symptoms.

It was first approved for treating rheumatoid arthritis by the FDA in 1998 after it was discovered (back in the 1970s) that a particular cytokine biologic cell could kill cancer cells in mice. This type of cell, which can lead to cancer activity, is called TNF. TNF or “tumor necrosis factor” was significantly studied in the 1980s and found to be high in not just cancer scenarios but also in RA patients as well. High levels of TNF were shown to cause body inflammation, fevers, increased white blood cells, and other issues in these patients. Thankfully, after this discovery, researchers grabbed the bull by the horns and began to study the potential use of this biologic cell to counteract those high TNF immune expressions and hopefully lessen symptoms (fun fact: the doctors who demonstrated the connection, Dr. Marc Feldmann and Ravinder N. Maini, won the 2003 Lasker Award for their work.)

You may be wondering, “I don’t have cancer, or RA; I have lupus. Why does my doctor think this medication will work for me?” Since its initial FDA approval in the late 1990’s, more research was conducted to determine how effective Rituxan was with depleting B-cells. It worked well with B-cell-driven cancers like lymphoma and on high TNF levels like RA. Thankfully, since systemic lupus is related to overactive B-cells, more studies confirmed that not only would Rituxan be helpful for RA but also other rheumatologic conditions like SLE.

How Does It Work?

Rituxan works by attaching to the surface of B cells and causing them to be destroyed. Since autoimmune diseases such as RA and SLE produce too many inflammatory-inducing cytokines (immune communication cells that include TNF, B-cells, and others), this medication may be used to help that overactive response when other treatments like Benlysta, azathioprine, and methotrexate do not work. Several studies have shown that Rituxan helps not only RA but SLE as well, including kidney nephritis.

In a nutshell: Overactive B-cells are believed to play a role in the symptoms and tissue damage of SLE. Rituxan targets and helps lower the amount of those cells by triggering the immune system to get rid of them.


In an excerpt from his new 2nd edition of The Lupus Encyclopedia, Dr. Don Thomas highlights that “A 2019 Italian Study of 80 patients treated with repetitive rituximab (Rituxan) courses showed that 1 out of 3 patients went into remission after the first treatment and stayed in remission for an average of 2 years. After the study was over and Rituxan was stopped, the researchers watched 75% of those patients. Half of them were still in remission after an additional 18 months of no rituximab treatment. SLE patients who were most likely to go into remission were those who had severe disease, had not failed numerous previous treatments, and did not have lupus arthritis.” (The Lupus Encyclopedia, Second Edition, p. 633)

Though the ultimate goal of using Rituxan is to lower inflammation and hopefully slow down or even prevent tissue damage from occurring, it has also been shown to help improve low platelets and autoimmune hemolytic anemia, lupus arthritis, Sjogren’s, CNS lupus, and as mentioned above, kidney nephritis.

Side Effects:

Because biologics are large and fragile cells, Rituxan must be given directly into the bloodstream for it to be effective. So, instead of being taken as a pill, it is given as an infusion, which is a needle placed in a vein. Rituxan infusions usually take about 5-8 hours. Usually, it is prescribed every six months after its initial loading dose.

Sometimes, with RA patients, it is given in conjunction with methotrexate or steroids. Infusion reactions can be common. However, that doesn’t necessarily mean they are severe. Most are mild and temporary histamine reactions, like headaches, fatigue, body aches, nausea, and itchy skin. Other symptoms like face flushing, high blood pressure, and water retention can be from the other medication given, not Rituxan. Antihistamines, steroids, and sometimes Tylenol are given to help counteract any temporary side effects.

The most common side-effects are:

  • infusion-related reactions

  • infections (may include fever, chills)

  • body aches

  • tiredness

  • nausea

For a full list of potential side effects, visit the Rituxan website, here.

Helpful Information

It is important to understand that this medication needs to be prescribed by a physician with a detailed account of your medical history.

Do not take this medication if you have active infections, congestive heart failure or severe arrhythmia, or have chronic hepatitis B infection. Discuss with your doctor if you are pregnant or plan to become pregnant. Rituxan may increase pregnancy risks and is recommended to stop 12 months before starting a family. Rituxan is such a large molecule that very little gets into breastmilk, and if any does, the baby’s stomach acid would destroy it. Therefore, it is safe to take during breastfeeding (but always ask your doctor first).

Please be clear with your healthcare providers about any medications, including prescription and over-the-counter medicines, vitamins, and herbal supplements you are taking. Tell your doctor if you take or have taken other immune suppressing medications. Also, it is important to avoid live vaccines, like Zostavax for shingles, if you are taking Rituxan.

Due to the complexity of making and administering the drug, it can be expensive to get. However, there are options for financial assistance. For financial aid call 877-436-3683 or visit the Rituxan website here: Apply for Financial Support | RITUXAN® (rituximab)


We hope this blog helps you make the best decision for your health if your doctor has recommended you try Rituxan. Many of us in the More Than Lupus community have been on it and have found it beneficial. We encourage you to share your experience with it, so that others can be more informed.

Written By:

Kelli Roseta

Reviewed and amended by: Donald Thomas, M.D., FACP. FACR, RhMSUS

**All resources provided by this blog are for informational purposes only, not to replace the advice of a medical professional. Kelli encourages you to always contact your medical provider with any specific questions or concerns regarding your illness. All intellectual property and content on this site and in this blog is owned by This includes materials protected by copyright, trademark, or patent laws. Copyright, More Than Lupus 2023.


The Lupus Encyclopedia, Second Edition, By Donald E. Thomas, Jr., MD, FACP, FACR, Johns Hopkins Press, 2023 p. 629-34

October 2023

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