Nimodipine and Clopidogrel: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Clopidogrel
Nimodipine
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Decreased antiplatelet effect and increased risk of thrombotic events
Interaction Deep Dive
Although the effects from coadministration of clopidogrel and nimodipine (a calcium channel blocker (CCB)) have not been studied in a large number of patients, in 2 prospective studies, other CCBs significantly decreased the effect of clopidogrel on platelet activity by CYP3A inhibition of the activation of clopidogrel to its active metabolite, and increased subsequent thrombotic events12. The addition of cilostazol may reduce these potentially harmful interactions 2. Caution is advised if clopidogrel and CCBs, such as nimodipine are used concurrently. Monitor patient for loss of clopidogrel efficacy.
Why it happens (mechanism)
Inhibition of CYP3A-mediated clopidogrel activation by nimodipine
Literature reports
2 reports — tap to read
a) In a prospective, observational study of 200 patients with coronary artery disease undergoing percutaneous coronary intervention, coadministration of clopidogrel and calcium channel blocking agents (n=45; amlodipine, n=35; nifedipine, nitrendipine, and diltiazem, n=3; nisoldipine, n=1) significantly decreased clopidogrel inhibitory effects as assessed by vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay. Platelet reactivity index (PRI) was significantly higher in patients receiving clopidogrel and a calcium channel blocker (61%) compared to patients receiving clopidogrel alone (48%). Similarly, decreased platelet inhibition by clopidogrel (PRI greater than 69%) was found in 40% of patients given both drugs compared with 20% of those treated with clopidogrel alone (p=0.008). No significant effect on platelet aggregation was seen in vitro when clopidogrel was combined with a calcium channel blocker, suggesting the interaction is mediated by the CYP3A4 enzyme. Patients were followed for 6 months, and those (25%) treated with clopidogrel and a calcium channel blocker experienced death from cardiovascular causes, non fatal myocardial infarction, stent thrombosis, revascularization, or coronary artery bypass graft compared with 8% of patients treated with clopidogrel alone 1.
b) In a post-hoc analysis of the prospective, randomized study of 900 Korean patients with coronary heart disease undergoing percutaneous coronary intervention (PCI) with drug-eluting stents, concomitant use of clopidogrel with aspirin and calcium channel blockers (CCB, n=239; amlodipine, 55%, n=132; diltiazem, 34.7%, n=83) significantly decreased the antiplatelet effect of clopidogrel as assessed by the VerifyNow P2Y12 assay and significantly increased the rate of a composite of cardiac death, non-fatal myocardial infarction, and ischemic stroke. In patients who received clopidogrel 75 mg/day and aspirin 100 mg/day, the on-treatment platelet reactivity (OPR) at discharge significantly increased with concomitant CCB use as compared with CCB non-use (mean OPR +/- standard error of the mean (SEM) 251.2+/-7.6 vs 225.6+/-5.1, respectively; p=0.008). However, this difference was moderated in those patients who received cilostazol 200 mg/day in addition to the clopidogrel plus aspirin therapy (mean OPR +/- SEM at discharge, 214.5+/-9.1 vs 203.4+/-5.6 for CCB users vs non-users; p=0.297). At the 6-month follow-up, these effects were maintained. A composite of cardiac death, non-fatal myocardial infarction, and ischemic stroke was also assessed at 6 months after PCI. This composite increased in patients who received clopidogrel and aspirin with CCB use as compared with CCB non-use (4.9% vs 0.9%, respectively; p=0.016), but not in patients who also received cilostazol (0% vs 1.8% for CCB users vs non-users; p=0.346) 2.
Common questions
Can I take Nimodipine and Clopidogrel together?
Decreased antiplatelet effect and increased risk of thrombotic events Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nimodipine and Clopidogrel interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Nimodipine or Clopidogrel need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Siller-Matula JM, Lang I, Christ G, et al: Calcium-channel blockers reduce the antiplatelet effect of clopidogrel. J Am Coll Cardiol 2008; 52(19):1557-1563. PubMed
- Lee SP, Bae JW, Park KW, et al: Inhibitory interaction between calcium channel blocker and clopidogrel. -Efficacy of cilostazol to overcome it-. Circ J 2011; 75(11):2581-2589. DOI
Keep reading about Clopidogrel
Keep reading about Nimodipine
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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