Benidipine Does Not Need to Be Withheld Before Rituximab Infusion
Continue benidipine 8 mg on the day of rituximab infusion—there is no evidence-based indication to withhold calcium channel blockers before rituximab administration.
Rationale for Continuing Benidipine
The primary concern with rituximab infusion is the risk of infusion-related reactions, particularly hypotension, which occurs in up to 77% of patients during the first infusion 1, 2. However, the management of these reactions does not involve withholding antihypertensive medications beforehand.
Standard Premedication Protocol
The established premedication regimen for rituximab focuses on preventing cytokine release and allergic-type reactions, not on manipulating baseline blood pressure:
- Mandatory premedication includes an antipyretic (acetaminophen 650-1000 mg) and antihistamine (diphenhydramine 25-50 mg) administered 30 minutes before infusion 1, 2
- Corticosteroid premedication (methylprednisolone 100 mg IV) is strongly recommended, especially for first infusions, as it reduces severe reactions from 4.7% to 1% 1
- No guideline recommends withholding calcium channel blockers or other antihypertensives before rituximab 1, 2, 3
Management of Hypotension During Infusion
If hypotension occurs during rituximab infusion, it is managed acutely rather than prevented by withholding antihypertensives:
- For Grade 1-2 reactions (mild hypotension): Stop or slow the infusion rate to 50%, provide symptomatic treatment, and resume at 50% of the previous rate after symptom resolution 2, 3
- For Grade 3 reactions (severe hypotension): Immediately stop the infusion, administer aggressive symptomatic treatment including IV fluids and corticosteroids, and consider permanent discontinuation 2, 3
- For Grade 4 reactions (cardiogenic shock): Permanently discontinue rituximab and provide full resuscitative measures 1, 2
Benidipine-Specific Considerations
Benidipine is a long-acting dihydropyridine calcium channel blocker with a 24-hour duration of action 4. Withholding a single morning dose would not meaningfully alter blood pressure during an infusion later that day, and abrupt discontinuation could cause rebound hypertension, which is itself a risk factor for cardiovascular complications during infusion 1.
Critical Monitoring Requirements
Rather than withholding benidipine, focus on appropriate monitoring during rituximab infusion:
- Continuous vital sign monitoring for at least 2 hours during infusion, particularly for high-risk patients 1
- Slow initial infusion rate: Start at 50 mg/hour for the first 30 minutes, increasing by 50 mg/hour every 30 minutes to a maximum of 400 mg/hour 1
- Post-infusion observation for a minimum of 1-2 hours after completion 2
Common Pitfall to Avoid
Do not withhold chronic antihypertensive medications before rituximab infusion based on theoretical concerns about hypotension. The infusion-related hypotension is cytokine-mediated and occurs acutely during infusion 1, 5, 6, not as a result of baseline blood pressure control. Maintaining stable baseline blood pressure with benidipine is preferable to creating hemodynamic instability by withholding it.