From the Guidelines
Rituximab is associated with significant side effects, including infusion-related reactions, which occur in 77% of patients during the first administration, and can be severe in 10% of cases, emphasizing the need for careful monitoring and premedication 1.
Common Side Effects
- Infusion reactions, such as fever, chills, nausea, headache, itching, and rash, are common and typically occur during the first infusion, with the incidence decreasing in subsequent treatments 1.
- Fatigue, weakness, and mild pain are also frequently experienced by patients.
Serious Side Effects
- Infections due to decreased immune function are a concern, as rituximab depletes B cells important for fighting infections, leading to serious infections like pneumonia, hepatitis B reactivation, and progressive multifocal leukoencephalopathy (PML) 1.
- Blood disorders, including neutropenia, thrombocytopenia, and anemia, may develop.
- Cardiac effects, such as arrhythmias and heart failure, have been reported.
- Gastrointestinal issues, including nausea, vomiting, and abdominal pain, are possible.
- Tumor lysis syndrome can occur in cancer patients, where rapid destruction of cancer cells releases harmful substances into the bloodstream.
Management and Prevention
- Patients should receive premedication, including an antipyretic and an antihistamine, to reduce the risk of infusion reactions, and a slow initial rate of infusion is recommended 1.
- Regular blood tests should be performed to check for cytopenias and infections.
- Hepatitis B screening is recommended before starting treatment to prevent reactivation.
- Close monitoring during infusions is crucial to promptly manage any adverse reactions that may occur.
From the FDA Drug Label
RITUXAN can cause serious side effects that can lead to death including: Infusion-related reactions. Serious infusion-related reactions can happen during your or your child's infusion or within 24 hours after your or your child's infusion of RITUXAN. Severe skin and mouth reactions. Hepatitis B virus (HBV) reactivation Progressive Multifocal Leukoencephalopathy (PML). Tumor Lysis Syndrome (TLS) Infections Cardiovascular Adverse Reactions Renal Toxicity Bowel Obstruction and Perforation Embryo-Fetal Toxicity Lactation
The side effects of rituximab include:
- Infusion-related reactions: hives, rash, itching, swelling, sudden cough, shortness of breath, difficulty breathing, wheezing, weakness, dizziness, palpitations, chest pain
- Severe skin and mouth reactions: painful sores, ulcers, blisters, peeling skin, rash, pustules
- Hepatitis B virus reactivation: worsening fatigue, yellowing of skin or eyes
- Progressive Multifocal Leukoencephalopathy (PML): confusion, dizziness, loss of balance, difficulty walking or talking, decreased strength, vision problems
- Tumor Lysis Syndrome (TLS): nausea, vomiting, diarrhea, lethargy
- Infections: fever, cold symptoms, flu symptoms, earache, headache, dysuria, oral herpes simplex infection, painful wounds
- Cardiovascular Adverse Reactions: ventricular fibrillation, myocardial infarction, cardiogenic shock, chest pain, irregular heartbeats
- Renal Toxicity: renal failure
- Bowel Obstruction and Perforation: severe abdominal pain, repeated vomiting
- Embryo-Fetal Toxicity: potential risk to fetus
- Lactation: advise women not to breastfeed during treatment with RITUXAN and for 6 months after the last dose 2 2
From the Research
Side Effects of Rituximab
The side effects of rituximab can be categorized into several areas, including:
- Infusion-related reactions
- Infections
- Hematological effects
- Immunological effects
Infusion-Related Reactions
Infusion-related reactions are common with rituximab, occurring in the majority of patients, and are usually mild to moderate flu-like symptoms that decrease in frequency with subsequent infusions 3. However, in approximately 10% of patients, severe infusion-related reactions can develop, including bronchospasm and hypotension 3. Anaphylaxis has also been reported in some cases, with a frequency of 3.6% in one study 4.
Infections
Infections are a significant concern with rituximab therapy, with 47.9% of patients experiencing infections in one study, and 17.9% experiencing severe infections 4. The risk of infection is increased with concurrent use of intravenous chemotherapy, treatment of systemic lupus erythematosus, neutropenia, and use of intravenous immunoglobulin 4. Reactivation of hepatitis and progressive multifocal leukoencephalopathy have also been reported as rare but serious infections associated with rituximab therapy 5, 6.
Hematological Effects
Rituximab can cause hematological effects, including late-onset neutropenia, which is a rare but potentially serious side effect 5. Leukoencephalopathy has also been reported in some cases 4.
Immunological Effects
Rituximab can also have immunological effects, including defects of immune reconstitution with associated immune compromise 5. B cell depletion is a common effect of rituximab therapy, with CD19+ or CD20+ cell numbers normalizing in a median of 9.0 months after therapy in one study 4. Immunoglobulin levels can also be affected, with low IgG and IgM levels developing in some patients after rituximab therapy 4.
Other Side Effects
Other side effects of rituximab include intestinal perforation and interstitial pneumonitis, which are rare but potentially serious 5, 6.