Is observation required after Truxima (rituximab) infusion?

Observation Requirements After Truxima (Rituximab) Infusion

Yes, observation is required after Truxima (rituximab) infusion due to the risk of potentially severe infusion-related reactions, particularly during the first infusion. 1, 2

Risk of Infusion Reactions

• Rituximab (including the biosimilar Truxima) can cause severe, including fatal, infusion-related reactions with time to onset typically between 30-120 minutes during the first infusion 1
• Up to 77% of patients may experience reactions during the first rituximab infusion, with severe reactions occurring in approximately 10% of cases 2
• Fatal infusion reactions have been reported and are characterized by hypoxia, pulmonary infiltrates, respiratory distress, myocardial infarction, ventricular fibrillation, and cardiogenic shock 2
• While most reactions occur during the first infusion (63%), reactions can also occur during subsequent infusions 3

Timing of Reactions

• Most infusion reactions occur within the first 30-120 minutes of starting the infusion 1
• However, some reactions can develop rapidly - within 5 minutes of starting the infusion, as documented in case reports 4
• Delayed reactions can also occur, with 10-30% of reactions happening in later infusions or after the initial observation period 5

Recommended Observation Protocol

• Patients should be closely monitored throughout the entire infusion and for a period afterward, especially during the first infusion 1, 2
• Particular attention should be given to patients with:
  • Pre-existing cardiac or pulmonary conditions
  • Prior cardiopulmonary adverse reactions
  • High numbers of circulating malignant cells (≥25,000/mm³) 1

Management of Reactions

• For mild to moderate reactions (Grade 1-2):
  • Stop or slow the infusion rate
  • Provide symptomatic treatment
  • Resume at half the previous rate after symptoms resolve 2
• For severe reactions (Grade 3-4):
  • Stop the infusion immediately
  • Provide aggressive symptomatic treatment
  • Permanently discontinue for Grade 4 reactions 2
• Institute medical management as needed (glucocorticoids, epinephrine, bronchodilators, or oxygen) 1

Premedication Recommendations

• All patients should receive premedication with:
  • Antihistamine (e.g., diphenhydramine)
  • Acetaminophen 1
• For rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis, and pemphigus vulgaris patients, methylprednisolone 100 mg IV or equivalent is recommended 30 minutes prior to each infusion 1

Practical Considerations

• While some studies have explored ultrafast 30-minute infusions of Truxima with oral premedication 6, this approach should only be considered for subsequent infusions after the patient has tolerated the first standard infusion without complications
• The decision to rechallenge after a reaction depends on the severity of the reaction:
  • Grade 1 reactions: Generally safe for same-day rechallenge
  • Grade 2 reactions: Variable outcomes with rechallenge (84% tolerate)
  • Grade 3-4 reactions: Rechallenge not recommended without allergy specialist consultation 3

Conclusion for Clinical Practice

• Given the significant risk of infusion reactions (77% for first infusion) and the potential for severe or even fatal outcomes, observation during and after Truxima infusion is required 2, 1
• While some institutions have moved toward shorter observation periods after uncomplicated first administrations of similar monoclonal antibodies 7, the FDA label for rituximab products still recommends close monitoring during and after infusion due to the risk profile 1