Rituximab belongs to the group of cancer-fighting medications known as antineoplastics. It is used to treat:

• certain forms of non-Hodgkin's lymphoma
• chronic lymphocytic leukemia (CLL)
• moderate-to-severe rheumatoid arthritis (in combination with methotrexate) for adults who have not responded to treatment with a group of medications called biologics or tumour necrosis factor (TNF) blockers
• granulomatosis with polyangiitis (Wegener's granulomatosis) and microscopic polyangiitis

Rituximab SC is only used to treat non-Hodgkin's lymphoma and CLL.

Rituximab treats cancer and inflammatory diseases by attacking and killing the cells that are causing the condition.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Rituximab IV:

This medication should only be given by health care professionals that are experienced in treating the conditions that rituximab is used for.

For non-Hodgkin's lymphoma and chronic lymphocytic leukemia, the recommended dose and dosing schedule of rituximab varies according to body size, the condition being treated, and other medications that are being used.

It is injected intravenously (into a vein) by a health care professional, usually in a clinical setting such as a hospital clinic, over a period of time. This process is called an intravenous infusion.

For rheumatoid arthritis, the recommended dose is 1,000 mg for the first dose, followed 2 weeks later by a second dose of 1,000 mg. The medication is injected into a vein (IV) over a period of time by a health care professional, usually in a clinic setting.

For Wegener's granulomatosis, the recommended dose is 375 mg/m² of body surface area, given once weekly for 4 weeks.

Very careful handling of this medication is required. It is always given under the supervision of a doctor in a hospital or similar setting, with access to sterile equipment for preparation.

It is important to receive this medication exactly as recommended by your doctor. If you miss an appointment to receive rituximab, contact your doctor as soon as possible to reschedule your appointment.

Many things can affect the dose and schedule of medication that a person needs, such as body size, other medical conditions, and other medications. Your doctor may choose a schedule different from the one above.

This medication should be stored in the refrigerator at 2°C to 8°C and protected from light.

Each mL of sterile, clear, colourless, preservative-free liquid concentrate for intravenous administration contains 10 mg of rituximab. Nonmedicinal ingredients: sodium chloride, tri-sodium citrate dihydrate, polysorbate 80, and water for injection.

Do not receive this medication if you:

• are allergic to rituximab or any ingredients of this medication
• are allergic to murine proteins, or Chinese Hamster Ovary (CHO) cell proteins
• have a severe, active infection
• have or have had progressive multifocal leukoencephalopathy (PML), a rare disorder associated with nerve damage in the brain

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is used in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who receives this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people receiving this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• cough
• diarrhea
• dizziness
• flushing
• general feeling of discomfort or illness
• headache
• itching
• itchy or watery eyes
• nausea
• pain at the infusion site
• redness, irritation, or pain at the injection site (rituximab SC only)
• runny nose
• sweating
• throat irritation
• vomiting
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• anxiety
• blood pressure changes
• chest tightness
• dizziness or lightheadedness when rising from a lying or sitting position
• feeling of swelling of tongue and throat
• fever and chills
• heart rate changes
• muscle or joint pain
• numbness or weakness on one side of your body
• redness or blistering of the skin or inside the mouth
• runny nose
• shortness of breath or difficulty breathing
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs and symptoms of kidney problems such as lower back or side pain, swelling of the feet or lower legs, or numbness or tingling in the feet or hands
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of heart problems (e.g., fast, irregular heartbeat or pulse, chest pain, sudden weight gain, difficulty breathing, leg swelling)
• signs of liver problems (including hepatitis B) such as abdominal pain, feeling of sickness, joint pain, loss of appetite, tiredness, yellowing of the skin and eyes (jaundice)
• skin rash or itchy skin
• stomach pain
• swelling of hands and feet
• symptoms of an infection such as fever, chills, pain, sore throat, redness or swelling, difficult or painful urination, cough
• symptoms of shingles such as itching, tingling, or severe burning pain with red patches that turn into blisters
• tingling sensations
• trouble thinking or memory problems
• unusual tiredness
• vision changes
• wheezing

Seek immediate medical attention if any of the following occur:

• chest pain or pressure
• difficulty breathing
• seizures
• signs of a severe skin rash (e.g., peeling or blistering skin, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools; spitting up of blood; vomiting blood or material that looks like coffee grounds)
• signs and symptoms of bowel blockage such as nausea, vomiting, abdominal swelling or pain, constipation, or diarrhea
• signs and symptoms of bowel perforation such as sudden abdominal pain (worse with movement), abdominal tenderness, high fever, chills, nausea, and vomiting
• signs of progressive multifocal leukoencephalopathy (PML) (e.g., memory loss, vision loss, difficulty thinking or walking)
• signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)
• symptoms of an allergic reaction such as difficulty breathing, hives, and swelling of the face or throat

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Allergic reactions: In rare cases, some people may develop a serious allergic reaction to this medication. Signs of an allergic reaction include a severe rash, hives, swollen face or throat, or difficulty breathing. If these occur, get immediate medical attention.

Blood clotting: This medication can reduce the number of platelet cells in the blood. Platelets help the blood to clot, and a shortage could make you bleed more easily.

Tell your doctor about any signs that your blood is not clotting as quickly as usual. Such symptoms may include black and tarry stools, blood in the urine, easy bruising, or cuts that won't stop bleeding.

Drowsiness and dizziness: Because this medication can cause drowsiness and dizziness, you should arrange to have someone drive you home after you receive this medication.

Heart problems: Rituximab causes temporary low blood pressure. Serious and potentially life-threatening heart problems have occurred for people who were using rituximab. If you have a heart problem (e.g., arrhythmia, angina, heart failure), you will be monitored closely by your doctor during the infusion and immediately after the infusion is finished.

If you are taking medication for high blood pressure, you may need to temporarily stop the medication while receiving rituximab. Talk to your doctor for more information.

Hepatitis B infection: There have been rare reports of the recurrence of hepatitis B infection in people receiving rituximab (often in combination with chemotherapy) who had previously been infected with the virus.

If you are at risk of hepatitis B infection, you should have a blood test before starting therapy to check if you carry the virus. Talk to your doctor if you are unsure whether you are at risk.

If you are a carrier of hepatitis B virus, had a previous infection, or are at risk of infection, your doctor will monitor you closely during rituximab therapy and for up to one year after finishing it for signs and symptoms of hepatitis B infection. These include abdominal or joint pain, loss of appetite, feeling of sickness, and yellowing of the skin and eyes (jaundice). If you experience these symptoms, contact your doctor immediately.

Infection: This medication can reduce the number of cells that fight infection in the body (white blood cells), increasing the risk of developing an infection or reactivating an inactive infection (e.g., herpes, shingles). Avoid contact with people with contagious infections. Severe viral infections have been reported up to one year after stopping treatment with rituximab.

If you notice signs of an infection such as fever, chills, pain, redness and swelling, pus, cough, or difficult or painful urination, contact your doctor as soon as possible.

This medication should also not be started while you have an active infection or a weakened immune system. While you are taking rituximab, your doctor will monitor you for signs of infection.

Infusion-related reactions: There have been reports of severe infusion-related reactions, sometimes resulting in death, in people with who were given rituximab intravenously. Your health care provider will closely monitor you during and after the infusion. These reactions usually occur within 30 minutes to 2 hours of starting the infusion.

If you experience symptoms of an infusion reaction, such as fever, chills, difficulty breathing, tightness of chest or throat, flushing, chest pain, stomach upset, rash, or a dramatic drop in blood pressure, tell your health care provider immediately.

It is important to take the medication(s) recommended by your doctor before your infusion of rituximab. If you experience a severe infusion reaction, your doctor will give you additional medications to treat the reaction. Ask your doctor for more information.

Lung disease: If you have pre-existing lung disease, you may be at greater risk of developing breathing difficulties during your rituximab infusion. Discuss any concerns you have with your doctor.

Progressive multifocal leukoencephalopathy (PML): There have been reports of PML after using rituximab. PML is a rare disorder that causes nerve damage in the brain. If you experience memory loss, vision loss, trouble thinking, or difficulty walking, contact your doctor immediately.

Tumour lysis syndrome (TLS): Rituximab may cause TLS, a potentially fatal condition that causes sudden kidney failure and abnormal heart rhythms. In the early stage of TLS, you may not have any symptoms, but your doctor will monitor for this condition with blood tests.

If you experience symptoms of TLS (e.g., a pounding, fast, or irregular heartbeat; vomiting; fatigue or weakness; difficulty concentrating; swelling, numbness or tingling in hands, face, or feet; back pain; muscle cramps; fainting; or trouble breathing), contact your doctor immediately.

Vaccines: Vaccines should not be given when you are receiving rituximab. Talk to your doctor if you need any vaccinations while taking this medication.

Pregnancy: This medication is not recommended for use during pregnancy. If you may become pregnant, use an effective method of birth control while you are using this medication, and for at least 12 months after the last treatment. Tell your doctor immediately if you become pregnant.

Breast-feeding: It is not known if rituximab passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between rituximab and any of the following:

• alpha-agonists (e.g., clonidine, methyldopa)
• alpha-blockers (e.g., alfuzosin, doxazosin, tamsulosin)
• angiotensin converting enzyme inhibitors (ACEIs; captopril, ramipril)
• angiotensin receptor blockers (ARBs; e.g., candesartan, irbesartan, losartan)
• bacillus Calmette-Guérin (BCG) (intravesical)
• belimumab
• beta-adrenergic blockers (e.g., atenolol, propranolol, sotalol)
• calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
• clozapine
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
• echinacea
• fingolimod
• leflunomide
• mesalamine
• natalizumab
• other biologics (e.g., abatacept, adalimumab, anakinra, denosumab, etanercept, infliximab, tocilizumab)
• ozanimod
• pimecrolimus
• roflumilast
• siponimod
• sulfasalazine
• tacrolimus
• vaccines

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.