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Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

  • Abdominal or stomach pain
  • Back pain
  • Black, tarry stools
  • Bleeding gums
  • Bloating or swelling of the face, arms, hands, lower legs, or feet
  • Blood in the urine or stools
  • Blurred vision
  • Body aches or pain
  • Chest pain
  • Confusion
  • Convulsions
  • Cough or hoarseness
  • Difficulty with breathing
  • Dizziness
  • Dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • Drowsiness
  • Dry mouth
  • Ear congestion
  • Fever and chills
  • Flushed, dry skin
  • Flushing of the face
  • Fruit-like breath odor
  • Headache
  • Hives or welts
  • Increased hunger
  • Increased thirst
  • Increased urination
  • Itching
  • Large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • Lower back or side pain
  • Nasal congestion
  • Nausea
  • Nervousness
  • Noisy breathing
  • Pain or tenderness around the eyes and cheekbones
  • Painful or difficult urination
  • Pale skin
  • Pinpoint red spots on the skin
  • Pounding in the ears
  • Rapid weight gain
  • Runny nose
  • Shortness of breath
  • Skin rash
  • Slow or fast heartbeat
  • Sneezing
  • Sore throat
  • Sores, ulcers, or white spots in the mouth or on the lips
  • Stuffy or runny nose
  • Sweating
  • Swelling of the tongue or throat
  • Swollen glands
  • Tightness of the chest
  • Tingling of the hands or feet
  • Troubled breathing with exertion
  • Unusual bleeding or bruising
  • Unusual tiredness or weakness
  • Unusual weight gain or loss
  • Vomiting
  • Wheezing

Less common

  • Blistering, peeling, or loosening of the skin
  • Blisters in the mouth
  • Blisters on the trunk, scalp, or other areas
  • Burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feeling
  • Burning, tingling, numbness or pain in the hands, arms, feet, or legs
  • Decreased frequency and amount of urination
  • Diarrhea
  • Difficulty with moving
  • Discouragement
  • Feeling of warmth
  • Feeling sad or empty
  • Increased thirst
  • Irregular heartbeat
  • Irritability
  • Joint or muscle pain
  • Loss of appetite
  • Loss of interest or pleasure
  • Muscle cramps
  • Muscle pain or stiffness
  • Nervousness
  • Numbness or tingling in the hands, feet, or lips
  • Pain at the place of injection
  • Pain, swelling, or redness in the joints
  • Red skin lesions, often with a purple center
  • Red, itchy lining of the eye
  • Redness of the face, neck, arms, and occasionally, upper chest
  • Stabbing pain
  • Swelling of the face or fingers
  • Swelling of the feet or lower legs
  • Trouble concentrating
  • Trouble sleeping

Incidence not known

  • Abdominal or stomach cramps or pain
  • Blindness
  • Blue-yellow color blindness
  • Blurred vision or other change in vision
  • Burning or stinging of the skin
  • Decreased vision
  • Dilated neck veins
  • Dry cough
  • Extreme fatigue
  • Eye pain, tearing
  • General feeling of discomfort, illness, or weakness
  • Irregular breathing
  • Nosebleed
  • Painful cold sores or blisters on the lips, nose, eyes, or genitals
  • Redness of the eye
  • Redness, soreness, or itching of the skin
  • Sensitivity of the eye to light
  • Severe abdominal or stomach pain
  • Severe vomiting, sometimes with blood
  • Sores, welting, or blisters
  • Swelling, stiffness, redness, or warmth around many joints
  • Swollen and inflamed joints
  • Swollen lymph glands
  • Vision loss

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Fear
  • Increased cough
  • Lack or loss of strength
  • Muscle aching or cramping
  • Night sweats
  • Swollen joints
  • Throat irritation

Less common

  • Agitation or anxiety
  • Change in taste
  • Dry eyes
  • Excessive muscle tone
  • Feeling of constant movement of self or surroundings
  • Heartburn
  • Increase in body movements
  • Lightheadedness
  • Muscle tension
  • Pain or redness at the injection site
  • Sensation of spinning
  • Sleepiness
  • Swelling of the stomach

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.


It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

This medicine may increase your risk of developing infections. Avoid being near people who are sick or have infections while you are using this medicine. Wash your hands often. Tell your doctor if you have lupus or if you have any kind of infection before you start using this medicine. Also tell your doctor if you have ever had an infection that would not go away or an infection that kept coming back.

This medicine may cause a rare and serious brain infection called progressive multifocal leukoencephalopathy (PML). The risk for getting this infection is higher if you have rheumatoid arthritis. Talk to your doctor about the benefits of taking this medicine and the risk of this infection. Check with your doctor right away if you are having more than one of these symptoms: vision changes, loss of coordination, clumsiness, memory loss, difficulty speaking or understanding what others say, and weakness in the legs.

Call your doctor right away if you start to have a cough that won’t go away, weight loss, night sweats, fever, chills, or flu-like symptoms, such as a runny or stuffy nose, headache, blurred vision, or feeling generally ill. These may be signs that you have an infection.

While you are being treated with rituximab, and after you stop treatment with it, do not have any immunizations (vaccinations) without your doctor’s approval. If you have rheumatoid arthritis, non-live virus vaccines should be given at least 4 weeks before receiving this medicine. Rituximab may lower your body’s resistance, and there is a chance you might get the infection the immunization is meant to prevent. In addition, other persons living in your household should not get live vaccines (e.g., nasal flu virus vaccine). Try to avoid persons who have taken live vaccines. Do not get close to them and do not stay in the same room with them for very long. If you cannot take these precautions, you should wear a protective face mask that covers the nose and mouth.

Rituximab may cause chest pain, fever, chills, itching, hives, flushing of the face, rash, troubled breathing, or swelling of the face, tongue, and throat within a few hours after you receive it. Check with your doctor or nurse right away if you have any of these symptoms.

This medicine may cause a serious type of reaction called tumor lysis syndrome (TLS). Your doctor may give you a medicine to help prevent this. Call your doctor right away if you have a decrease or change in urine amount; joint pain, stiffness, or swelling; lower back, side, or stomach pain; a rapid weight gain; swelling of the feet or lower legs; or unusual tiredness or weakness.

Serious skin reactions can occur during treatment with this medicine. Stop using this medicine and check with your doctor right away if you have blistering, peeling, or loosening of the skin; red skin lesions; severe acne or skin rash; sores or ulcers on the skin; or fever or chills while you are using this medicine.

Stop using this medicine and check with your doctor immediately if you have any symptoms of liver problems including skin and eyes turning yellow, dark brown-colored urine, right-sided abdominal or stomach pain, fever, or severe tiredness.

This medicine may cause serious stomach and bowel problems, especially when used with other cancer medicines. Check with your doctor right away if you start having stomach pain while being treated with this medicine.

Use an effective form of birth control to keep from getting pregnant. You should not become pregnant while you are using this medicine and for 12 months after stopping it. Talk to your doctor about effective birth control.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Proper Use

Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.

You will receive this medicine while you are in a hospital or cancer treatment center. A nurse or other trained health professional will give you this medicine. This medicine is given through a needle placed in one of your veins.

Rituximab must be given slowly, so the needle will remain in place for a few hours. You may also receive medicines to help prevent possible allergic reactions to the injection.

This medicine should come with a Medication Guide. It is very important that you read and understand this information. ask your doctor about anything you do not understand.

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of rituximab injection in the pediatric population. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of rituximab injection in the elderly. However, elderly patients are more likely to have infections and age-related heart and lung problems, which may require caution in patients receiving rituximab injection.


Pregnancy Category Explanation
All Trimesters C Animal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Rotavirus Vaccine, Live

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Adenovirus Vaccine Type 4, Live
  • Adenovirus Vaccine Type 7, Live
  • Bacillus of Calmette and Guerin Vaccine, Live
  • Cisplatin
  • Influenza Virus Vaccine, Live
  • Measles Virus Vaccine, Live
  • Mumps Virus Vaccine, Live
  • Rotavirus Vaccine, Live
  • Rubella Virus Vaccine, Live
  • Smallpox Vaccine
  • Typhoid Vaccine
  • Varicella Virus Vaccine
  • Yellow Fever Vaccine

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Pneumococcal Vaccine Polyvalent

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Angina (chest pain), history of or
  • Heart disease or
  • Heart rhythm problems (e.g., arrhythmia), history of or
  • Hepatitis B or
  • Kidney disease or
  • Lung problems (e.g., asthma, bronchitis), history of or
  • Stomach or bowel problems (e.g., intestinal blockage, perforation, ulcers)—Use with caution. May make these conditions worse.
  • Infection—May decrease your body’s ability to fight infection.


Rituximab injection is a monoclonal antibody. It is used to treat a type of cancer called non-Hodgkin’s lymphoma (NHL). It can be used alone or with other cancer medicines (chemotherapy). It is also used as a “maintenance” treatment for patients with advanced follicular lymphoma who responded to initial treatment with this medicine plus chemotherapy (induction treatment).

Rituximab is also used in combination with fludarabine and cyclophosphamide (FC) for the treatment of chronic lymphocytic leukemia (CLL).

Rituximab may also be used in combination with methotrexate to reduce the signs and symptoms of rheumatoid arthritis and help keep joint damage from getting worse after at least one other medicine (e.g., adalimumab, etanercept, infliximab) has been used and did not work well.

Rituximab is also used in combination with glucocorticoids to treat Wegener’s granulomatosis (WG) and microscopic polyangiitis (MPA).

This medicine is to be administered only by or under the immediate supervision of your doctor.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, rituximab is used in certain patients with the following medical conditions:

  • Immune or idiopathic thrombocytopenic purpura (ITP) (a blood disease).
  • Waldenstrom’s macroglobulinemia (cancer of the blood).