Clopidogrel and Meperidine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Clopidogrel
Meperidine
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
Reduced efficacy of clopidogrel, an increased meperidine exposure and an increased risk of meperidine-related adverse effects
Interaction Deep Dive
Coadministration of meperidine (opioid agonist) with clopidogrel delays and reduces the absorption of clopidogrel, presumably because of slowed gastric emptying, resulting in reduced exposure to clopidogrel metabolites. AUC and Cmax of clopidogrel metabolites were reduced when coadministered with morphine IV. Consider the use of a parenteral antiplatelet agent in acute coronary syndrome patients requiring coadministration of morphine or other opioid agonists1. Additionally, concomitant use of meperidine (a CYP2B6 substrate) and clopidogrel (CYP2B6 inhibitor) may increase the plasma concentrations of meperidine, prolong opioid adverse reactions, and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dosage of meperidine is achieved. Consider dosage reduction of meperidine when using concomitant clopidogrel in meperidine-treated patients, and follow patients closely at frequent intervals for signs and symptoms of respiratory depression and sedation. When discontinuing clopidogrel, follow patients for signs or symptoms of opioid withdrawal and consider increasing the meperidine dosage as needed 2.
Why it happens (mechanism)
Delayed and reduced absorption of clopidogrel; inhibition of CYP2B6-mediated metabolism of meperidine
Literature reports
1 report — tap to read
a) Coadministration of morphine 5 mg IV with a 600-mg loading dose of clopidogrel in healthy adults decreased the AUC and Cmax of the thiol metabolites of clopidogrel by 34%. Mean platelet aggregation was higher up to 2 to 4 hours with morphine coadministration 1.
Common questions
Can I take Clopidogrel and Meperidine together?
Reduced efficacy of clopidogrel, an increased meperidine exposure and an increased risk of meperidine-related adverse effects Always confirm with your pharmacist or prescriber before making any change.
How serious is the Clopidogrel and Meperidine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
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 Clopidogrel or Meperidine 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)
- Product Information: PLAVIX(R) oral tablets, clopidogrel bisulfate oral tablets. sanofi-aventis US LLC (per FDA), Bridgewater, NJ, 2022. DailyMed
- Product Information: MEPERGAN intramuscular, intravenous injection, meperidine HCl, promethazine HCl intramuscular, intravenous injection. West-Ward Pharmaceuticals Corp (per FDA), Eatontown, NJ, 2023.
Keep reading about Clopidogrel
Keep reading about Meperidine
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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