Clopidogrel is a prodrug. It inhibits platelet activation and aggregation through the irreversible binding of its active metabolite to the P2Y12 class of ADP receptors on platelets. Dose-dependent inhibition of platelet aggregation can be seen at 2 hours after single oral doses. Repeated doses of 75 mg per day inhibit ADP-induced platelet aggregation on the first day, and inhibition reaches steady state between Day 3 and Day 7.
Aspirin inhibits platelet aggregation by irreversible inhibition of platelet cyclooxygenase and thus inhibiting the generation of thromboxane A2 a powerful inducer of platelet aggregation and vasoconstriction.
Acute Coronary Syndrome (ACS): It is indicated to reduce the rate of Myocardial Infarction (MI) and Stroke in patients with non-ST-segment elevation ACS [unstable angina (UA)/non-ST-elevation Myocardial Infarction (NSTEMI)] and acute ST-segment elevation ACS [ST-elevation Myocardial Infarction (STEMI)].
Recent MI, recent Stroke, or established Peripheral Arterial Disease: In patients with established peripheral arterial disease or with a history of recent Myocardial Infarction (MI) or recent Stroke it is indicated to reduce the rate of MI and Stroke.
This combination is contraindicated in the following conditions: Hypersensitivity to the drug substance or any component of the product. Active pathological bleeding such as peptic ulcer or intracranial hemorrhage.
This combination is generally well tolerated.
There are no adequate and well-controlled studies in pregnant women. It should be used during first and second trimesters of pregnancy only if clearly needed. It is contraindicated during the third trimester of pregnancy. It is unknown whether Clopidogrel is excreted in human breast milk but Aspirin is known to be excreted in human milk. This Drug should be discontinued during the breast feeding.
This combination may prolongs the bleeding time.
Thrombotic thrombocytopenic purpura (TTP): TTP has been reported rarely following use of this combination.
Reye's syndrome: Reye's syndrome may develop in individuals who have chicken pox, influenza or flu symptoms. Hypersensitivity including rash, angioedema or hematologic reaction has been reported in patients receiving this combination or history of hypersensitivity to other thienopyridines
It should not be given to children, particularly those under 12 years, unless the expected benefits outweight the possible risks. Aspirin may be a contributory factor in the causation of Reye’s syndrome in some children.
Clopidogrel overdose may lead to bleeding complications. Based on biological plausibility, platelet transfusion may restore clotting ability. In moderate aspirin intoxication dizziness, headache, tinnitus, confusion, and gastrointestinal symptoms may occur which can be treated by inducing vomiting followed by gastric lavage if needed. In severe Aspirin intoxication respiratory alkalosis respiratory acidosis, metabolic acidosis, hyperthermia, perspiration, dehydration can occur. It can be treated with haemodialysis and other symptomatic treatment.