Clopidogrel (Plavix)
Thienopyridine prodrug converted to active metabolite via two-step CYP450 oxidation (CYP2C19 key enzyme) followed by hydrolysis. Only ~15% of absorbed dose is bioactivated; 85% hydrolyzed to inactive metabolites by carboxylesterase-1. Active metabolite H4 irreversibly binds to P2Y12 ADP receptors on platelets, inhibiting aggregation. Significant CYP2C19 genetic polymorphism: poor metabolizers (~13-15%) show markedly reduced antiplatelet effect and higher cardiovascular event rates. Genetic testing increasingly recommended. FDA label includes CYP2C19 genotype-based dosing recommendation. High loading dose (300-600 mg) often used for acute coronary syndromes.
Projected serum levels — 75 mg, once daily
Maintenance schedule: 75 mg once daily (oral).
Loading schedule: 122 mg on day 1, then 75 mg once daily — reaching therapeutic levels sooner.
Modeled steady state after ~2 days: peak ≈ 0.33 mg, trough ≈ 0.14 mg body load. Population-based estimate over 15 days for a 75 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.
Key facts
- Category
- Antiplatelet
- Route modeled
- Oral
- Model confidence
- predicted
- Half-life
- 6 h
- Common dose
- 75 mg
- Suggested maximum
- 300 mg/day
- Reference dose range
- 37.5–300 mg (single dose)
- Suggested cadence
- once daily
- Validated against
- 75 mg oral — Cmax 0.003 mg/L at 0.75 h
Documented interactions
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danger
Fluvoxamine (Luvox) + Clopidogrel (Plavix)
Fluvoxamine is a strong CYP2C19 inhibitor. Clopidogrel requires CYP2C19-mediated bioactivation to its active metabolite. Inhibition reduces active metabolite formation by up to 50%, increasing stent…
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danger
Levothyroxine (Synthroid) + Clopidogrel (Plavix)
Clopidogrel (Plavix) may displace Levothyroxine (Synthroid) from plasma protein binding sites, transiently raising free drug concentration. This drug has a narrow therapeutic index; free…
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danger
Montelukast (Singulair) + Clopidogrel (Plavix)
Clopidogrel (Plavix) reversible_inhibitor of CYP2C8 predicted to change Montelukast (Singulair) AUC by ~2.07x
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danger
Pioglitazone + Clopidogrel (Plavix)
Clopidogrel (Plavix) reversible_inhibitor of CYP2C8 predicted to change Pioglitazone AUC by ~2.07x
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danger
Tacrolimus (Prograf) + Clopidogrel (Plavix)
Clopidogrel (Plavix) may displace Tacrolimus (Prograf) from plasma protein binding sites, transiently raising free drug concentration. This drug has a narrow therapeutic index; free concentration…
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danger
Warfarin (Coumadin) + Clopidogrel (Plavix)
Clopidogrel (Plavix) may displace Warfarin (Coumadin) from plasma protein binding sites, transiently raising free drug concentration. This drug has a narrow therapeutic index; free concentration…
Serum checks 177 modeled interaction pairings for clopidogrel (plavix) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.
Research behind this entry
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Clinical Pharmacokinetics and Pharmacodynamics of Clopidogrel
Comprehensive review of clopidogrel prodrug activation, active metabolite pharmacokinetics, CYP2C19 polymorphism effects on bioactivation, and clinical consequences for antiplatelet response.
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Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2C19 Genotype and Clopidogrel Therapy: 2022 Update
Updated CPIC guidelines recommending CYP2C19 genotype-based clopidogrel dosing: alternatives for poor metabolizers, standard dosing for normal/rapid metabolizers.
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Carboxylesterase-mediated inactivation of the prodrug clopidogrel is enhanced by P2Y12 inhibition
Mechanism study showing carboxylesterase-1 hydrolysis of clopidogrel to inactive acid metabolite is major elimination pathway, accounting for 85% of absorbed drug.
3 published studies referenced in the app, each with a plain-language summary.