A fixed-dose combination (FDC) of two antiplatelet agents used for secondary prevention of atherothrombotic events. Aspirin (acetylsalicylic acid) is a non-selective, irreversible cyclooxygenase (COX) inhibitor. Clopidogrel is a thienopyridine prodrug that irreversibly inhibits the P2Y12 subtype of the ADP receptor on platelets. This dual antiplatelet therapy (DAPT) provides synergistic platelet inhibition, significantly reducing the risk of recurrent ischemic events like myocardial infarction (MI) and stroke, but at the cost of an increased bleeding risk. Its use is a cornerstone of management post-acute coronary syndrome (ACS) and percutaneous coronary intervention (PCI) with stent placement.
Adult: One tablet (Aspirin 150mg + Clopidogrel 75mg) orally once daily. For ACS/PCI: A loading dose of Clopidogrel (300mg or 600mg) and Aspirin (150-325mg) is typically given initially, followed by this maintenance combination. The exact duration (e.g., 6-12 months for DES, 1 month for BMS, or longer based on ischemic/bleeding risk) must be determined by the cardiologist.
Note: Take with or without food. To reduce gastric irritation, it is recommended to take with a full glass of water and with food. Do not crush or chew the tablet unless specifically instructed (some brands may have a special formulation). Swallow whole. Take at the same time each day. If a dose is missed, take it as soon as remembered. If it is almost time for the next dose, skip the missed dose. Do not double the dose.
The combination provides synergistic, irreversible inhibition of platelet activation and aggregation via two distinct pathways. Aspirin irreversibly acetylates serine 530 of cyclooxygenase-1 (COX-1) enzyme in platelets, inhibiting the conversion of arachidonic acid to thromboxane A2 (TXA2), a potent vasoconstrictor and platelet aggregator. Clopidogrel, after metabolic activation, irreversibly binds to the P2Y12 subtype of the adenosine diphosphate (ADP) receptor on the platelet surface, inhibiting ADP-mediated activation of the glycoprotein GPIIb/IIIa complex, which is the final common pathway for platelet aggregation. This dual blockade provides more comprehensive platelet inhibition than either agent alone.
Pregnancy: Category D (Aspirin) and Category B (Clopidogrel). Aspirin is contraindicated, especially in the third trimester, due to risk of premature closure of ductus arteriosus, prolonged labor, increased maternal bleeding, and potential adverse fetal effects. Clopidogrel should be used only if clearly needed. This combination is generally avoided during pregnancy. Consult a cardiologist and obstetrician for high-risk scenarios.
Driving: Dizziness and vertigo have been reported. Patients should be cautioned about driving or operating machinery if they experience these effects.
| Warfarin, NOACs (Apixaban, Rivaroxaban, Dabigatran) | Profoundly increased risk of major and fatal bleeding. | Contraindicated / High |
| NSAIDs (Ibuprofen, Diclofenac, Naproxen) | Increased risk of GI bleeding and ulceration. Ibuprofen may competitively inhibit aspirin's antiplatelet binding site. | High |
| Proton Pump Inhibitors (especially Omeprazole, Esomeprazole) | Potentially reduce the antiplatelet effect of Clopidogrel by inhibiting CYP2C19, required for its activation. Pantoprazole or Rabeprazole are preferred. | Moderate |
| Selective Serotonin Reuptake Inhibitors (SSRIs e.g., Fluoxetine, Sertraline) | Increased bleeding risk due to impaired platelet serotonin uptake. | Moderate |
| Corticosteroids (e.g., Prednisolone) | Increased risk of GI ulceration and bleeding. | Moderate |
| Methotrexate | Aspirin reduces renal clearance of methotrexate, increasing risk of severe hematologic and GI toxicity. | High |
| CYP2C19 Inhibitors (e.g., Fluconazole, Fluoxetine, Cimetidine) | May reduce conversion of Clopidogrel to its active form, diminishing antiplatelet effect. | Moderate |
| CYP2C19 Inducers (e.g., Rifampicin) | May increase antiplatelet effect of Clopidogrel, potentially increasing bleeding risk. | Moderate |
Same composition (Aspirin (150mg) + Clopidogrel (75mg)), different brands: