Contraindications for Rituximab (Rituxan)
Rituximab has no absolute contraindications according to the FDA label, but several important relative contraindications and precautions must be considered before administration. 1
Primary Contraindications and Precautions
Infection-Related Precautions
- Active infections: Withhold rituximab in patients with active, severe infections until the infection is controlled 1
- Hepatitis B: Screen for hepatitis B before initiating therapy, as reactivation of occult hepatitis B infection has been reported 2
- Progressive multifocal leukoencephalopathy (PML): Rare but serious complication that requires immediate discontinuation
Cardiac Precautions
- Pre-existing cardiac conditions: Higher risk for severe infusion reactions in patients with cardiac disease 2
- History of cardiopulmonary adverse reactions: Increased risk for severe infusion-related reactions 2
Hematologic Considerations
- High circulating malignant cell count: Increased risk for severe infusion reactions and tumor lysis syndrome 2
- Severe cytopenias: Use with caution in patients with pre-existing cytopenias
Special Population Considerations
Pregnancy and Lactation
- Pregnancy: Can cause fetal harm; advise females of reproductive potential about risks 1
- Lactation: Not recommended during treatment and for at least 6 months after the last dose 1
Pediatric Patients
- Higher risk of serum sickness in pediatric patients with ITP 2
- Increased infusion reactions: Approximately 47% of children experience chills, fever, and respiratory symptoms with first dose 2
Monitoring and Management
Pre-Treatment Assessment
- Complete blood count
- Hepatitis B screening
- Immunoglobulin levels (baseline)
- CD19+ B cell counts (when appropriate)
During Treatment
- Monitor for infusion-related reactions, particularly during first infusion 2
- For mild to moderate reactions: temporarily slow or interrupt infusion
- For severe reactions: discontinue infusion and provide supportive care 2
Post-Treatment Monitoring
- Regular monitoring of B-cell counts and immunoglobulin levels in patients receiving repeated courses 2
- Monitor for hypogammaglobulinemia, especially with prolonged or repeated treatment 2
Disease-Specific Considerations
ANCA-Associated Vasculitis
- In patients with severe renal disease (serum creatinine >4.0 mg/dL) or on mechanical ventilation for alveolar hemorrhage, comparability with cyclophosphamide has not been proven 3
- Consider plasma exchange for patients with serum creatinine >3.4 mg/dL, requiring dialysis, or with diffuse alveolar hemorrhage with hypoxemia 3
Hairy Cell Leukemia
- Consider avoiding rituximab in patients scheduled for SARS-CoV-2 vaccination due to potential reduced vaccine efficacy 3
- The immunosuppressive effects of rituximab may outweigh benefits in certain clinical scenarios during infectious disease outbreaks 3
Risk Factors for Complications
Infection Risk
- Combined use with other immunosuppressants (particularly antithymocyte globulin) 4
- Higher number of rituximab courses 4
- Higher pre-treatment CD19 and CD20 levels 4
- Concomitant high-dose glucocorticoid therapy 5
Remember that while rituximab has no absolute contraindications per the FDA label, careful assessment of risk factors and appropriate monitoring are essential to minimize adverse events and optimize treatment outcomes.