Overview
11 DESCRIPTION Clopidogrel bisulfate is a thienopyridine class inhibitor of P2Y 12 ADP platelet receptors. Chemically it is methyl (+)-( S )-α-(2-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4 H )-acetate sulfate (1:1). The molecular formula of clopidogrel bisulfate is C 16 H 16 ClNO 2 S•H 2 SO 4 and its molecular weight is 419.9.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Clopidogrel is an inhibitor of platelet activation and aggregation through the irreversible binding of its active metabolite to the P2Y 12 class of ADP receptors on platelets. 12.2 Pharmacodynamics Clopidogrel must be metabolized by CYP450 enzymes to produce the active metabolite that inhibits platelet aggregation. The active metabolite of clopidogrel selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet P2Y 12 receptor and the subsequent ADP-mediated activation of the glycoprotein GPIIb/IIIa complex, thereby inhibiting platelet aggregation. This action is irreversible. Consequently, platelets exposed to clopidogrel’s active metabolite are affected for the remainder of their lifespan (about 7 to 10 days).
Indications
- 1 INDICATIONS AND USAGE Clopidogrel tablets are a P2Y 12 platelet inhibitor indicated for: Acute coronary syndrome – For patients with non–ST-segment elevation ACS (unstable angina [UA]/non–ST-elevation myocardial infarction [NSTEMI]), clopidogrel tablets have been shown to reduce the rate of myocardial infarction (MI) and stroke. (1.1) – For patients with ST-elevation myocardial infarction (STEMI), clopidogrel tablets have been shown to reduce the rate of MI and stroke. (1.1) Recent MI, recent stroke, or established peripheral arterial disease.
Common Doses
- 300 mg
- 75 mg
Dosage
2 DOSAGE AND ADMINISTRATION Acute coronary syndrome ( 2.1 ) – Initiate clopidogrel tablets with a single 300 mg oral loading dose and then continue at 75 mg once daily. – Initiating clopidogrel tablets without a loading dose will delay establishment of an antiplatelet effect by several days. Recent MI, recent stroke, or established peripheral arterial disease: 75 mg once daily orally without a loading dose. ( 2.2 ) 2.1 Acute Coronary Syndrome In patients who need an antiplatelet effect within hours, initiate clopidogrel tablets with a single 300 mg oral loading dose and then continue at 75 mg...
Black Box Warning
WARNING: DIMINISHED ANTIPLATELET EFFECT IN PATIENTS WITH TWO LOSS-OF-FUNCTION ALLELES OF THE CYP2C19 GENE The effectiveness of clopidogrel results from its antiplatelet activity, which is dependent on its conversion to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19 [see Warnings and Precautions (5.1) , Clinical Pharmacology (12.3) ] . Clopidogrel at recommended doses forms less of the active metabolite and so has a reduced effect on platelet activity in patients who are homozygous for nonfunctional alleles of the CYP2C19 gene, (termed “CYP2C19 poor...
Contraindications
- 4 CONTRAINDICATIONS Active pathological bleeding, such as peptic ulcer or intracranial hemorrhage (4.1) Hypersensitivity to clopidogrel or any component of the product (4.2) 4.1 Active Bleeding Clopidogrel tablets are contraindicated in patients with active pathological bleeding such as peptic ulcer or intracranial hemorrhage. 4.2 Hypersensitivity Clopidogrel tablets are contraindicated in patients with hypersensitivity (e.g., anaphylaxis) to clopidogrel or any component of the product [see Adverse Reactions (6.2) ] .
Side Effects
- 6 ADVERSE REACTIONS The following serious adverse reactions are discussed below and elsewhere in the labeling: Bleeding [see Warnings and Precautions (5.2) ] Thrombotic thrombocytopenic purpura [see Warnings and Precautions (5.4) ] Bleeding, including life-threatening and fatal bleeding, is the most commonly reported adverse reaction. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.
Interactions
- 7 DRUG INTERACTIONS CYP2C19 inducers: Increases levels of clopidogrel active metabolite and increases platelet inhibition. ( 7.1 ) Opioids: Decreased exposure to clopidogrel. Consider use of parenteral antiplatelet agent. ( 7.3 ) Nonsteroidal anti-inflammatory drugs (NSAIDs), warfarin, selective serotonin and serotonin norepinephrine reuptake inhibitors (SSRIs, SNRIs): Increases risk of bleeding. ( 7.4 , 7.5 , 7.6 ) Other Antiplatelet Agents: Increases the risk of bleeding due to an additive effect. ( 7.7 ) Repaglinide (CYP2C8 substrates): Increases substrate plasma concentrations. ( 7.8 ) 7.