Does Cimetidine Interact with Nimodipine?
Cimetidine and Nimodipine have a moderate drug interaction according to U.S. FDA drug labeling data. Moderate CYP3A4 inhibitor that increases nimodipine plasma concentration. A study showed 50% increase in peak concentrations and 90% increase in area under curve. Blood pressure monitoring and dose reduction may be necessary. The mechanism involves cyp3a4 inhibition decreases first-pass metabolism of nimodipine. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Moderate
- Cimetidine Class
- Histamine-2 Receptor Antagonist
- Nimodipine Class
- Dihydropyridine Calcium Channel Blocker
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Cimetidine and Nimodipine occurs because cyp3a4 inhibition decreases first-pass metabolism of nimodipine. Clinically, this means moderate cyp3a4 inhibitor that increases nimodipine plasma concentration. a study showed 50% increase in peak concentrations and 90% increase in area under curve. blood pressure monitoring and dose reduction may be necessary. This is classified as a moderate interaction. While it may not require stopping either medication, your healthcare provider should be aware you are taking both so they can monitor for potential effects and adjust treatment if necessary.
What To Tell Your Doctor or Pharmacist
If you are taking Cimetidine and your doctor is considering prescribing Nimodipine (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider