Nimodipine Administration for Subarachnoid Hemorrhage
Nimodipine should be administered orally at a dose of 60 mg every 4 hours for 21 consecutive days, starting within 96 hours of subarachnoid hemorrhage onset. 1
Recommended Administration Route and Dosing
The American Heart Association/American Stroke Association strongly recommends oral nimodipine administration (Class I, Level A evidence) 1
Standard dosing:
- 60 mg (two 30 mg capsules) every 4 hours
- Continue for 21 consecutive days
- Start as soon as possible within 96 hours of SAH onset
For patients who cannot swallow capsules:
- Extract contents from capsules
- Administer via nasogastric tube or PEG
- Flush with 30 mL normal saline 1
Important Cautions Regarding IV Administration
- Nimodipine should NOT be administered intravenously due to risk of severe hypotension 1
- While some research has studied IV nimodipine 2, this is not the recommended route according to current guidelines
- Significant blood pressure drops occur in approximately 30% of patients with IV administration, requiring vasopressor support in 50% of cases 2
Special Dosing Considerations
- Liver dysfunction/cirrhosis: Reduce dose to 30 mg every 4 hours with close monitoring for hypotension 1
- Elderly patients: Consider dose reduction due to approximately 2× higher plasma concentrations 1
- Hypotension management:
- Mild hypotension: Continue nimodipine
- Severe hypotension: Temporarily reduce dose or discontinue 1
Clinical Efficacy and Importance
- Nimodipine reduces the severity of neurological deficits resulting from vasospasm
- Significantly improves long-term clinical outcomes
- Reduces risk of cerebral infarction by 34% and poor outcomes by 40% 3
- Only effective drug for prevention of vasospasm in aSAH patients 4
Common Pitfalls to Avoid
- Premature discontinuation: Only 33% of patients complete the full 21-day course in some studies 4
- Failure to continue after discharge: 47% of patients discharged before 21 days do not receive prescriptions to continue at home 4
- Using other calcium channel blockers: Only nimodipine has strong evidence for improving outcomes in SAH 1
- Administering intravenously: This can cause severe hypotension and is not recommended 1
- Concurrent use with grapefruit juice: Should be avoided as it affects metabolism 1
Management of Side Effects
- Monitor for hypotension (occurs in up to 78% of patients)
- Higher baseline systolic blood pressure is associated with greater risk of >10% drops in SBP after nimodipine administration 2
- Maintain euvolemia rather than hypervolemia or hypovolemia 1
- Avoid prophylactic hemodynamic augmentation 1
Nimodipine remains the cornerstone of medical management for preventing delayed cerebral ischemia after subarachnoid hemorrhage, with consistent evidence supporting its oral administration for improved neurological outcomes.