Clopidogrel

1 INDICATIONS & USAGE Clopidogrel is 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 has been shown to reduce the rate of myocardial infarction (MI) and stroke. ( 1.1 ) - For patients with ST-elevation myocardial infarction (STEMI), clopidogrel has been shown to reduce the rate of MI and stroke. ( 1.1 ) • Recent MI, recent stroke, or established peripheral arterial disease. Clopidogrel has been shown to reduce the rate of MI and stroke. ( 1.2 ) 1.1 Acute Coronary Syndrome (ACS) • Clopidogrel 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]), including patients who are to be managed medically and those who are to be managed with coronary revascularization. Clopidogrel should be administered in conjunction with aspirin. • Clopidogrel is indicated to reduce the rate of myocardial infarction and stroke in patients with acute ST-elevation myocardial infarction (STEMI) who are to be managed medically. Clopidogrel should be administered in conjunction with aspirin. 1.2 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 clopidogrel is indicated to reduce the rate of MI and stroke.

2 DOSAGE & ADMINISTRATION • Acute coronary syndrome ( 2.1 ) - Initiate clopidogrel with a single 300 mg oral loading dose and then continue at 75 mg once daily. - Initiating clopidogrel 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 with a single 300 mg oral loading dose and then continue at 75 mg once daily. Initiating clopidogrel without a loading dose will delay establishment of an antiplatelet effect by several days [ see Clinical Pharmacology ( 12.3 ) and Clinical Studies ( 14.1 ) ]. 2.2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease 75 mg once daily orally without a loading dose [ see Clinical Pharmacology ( 12.3 ) and Clinical Studies ( 14.2 ) ].

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 Macleods Pharma USA, Inc. at 1-888-943-3210 or 1-855-926-3384 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions and durations of follow-up, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Clopidogrel has been evaluated for safety in more than 54,000 patients, including over 21,000 patients treated for one year or more. The clinically important adverse reactions observed in trials comparing clopidogrel plus aspirin to placebo plus aspirin and trials comparing clopidogrel alone to aspirin alone are discussed below. Bleeding CURE In CURE, clopidogrel use with aspirin was associated with an increase in major bleeding (primarily gastrointestinal and at puncture sites) compared to placebo with aspirin (see Table 1). The incidence of intracranial hemorrhage (0.1%) and fatal bleeding (0.2%) were the same in both groups. Other bleeding events that were reported more frequently in the clopidogrel group were epistaxis, hematuria, and bruise. The overall incidence of bleeding is described in Table 1. Table 1: CURE Incidence of Bleeding Complications (% patients) Event Clopidogrel (+ aspirin) Placebo (+ aspirin) (n=6259) (n=6303) Major bleeding* 3.7 2.7 Life-threatening bleeding 2.2 1.8 Fatal 0.2 0.2 5 g/dL hemoglobin drop 0.9 0.9 Requiring surgical intervention 0.7 0.7 Hemorrhagic strokes 0.1 0.1 Requiring inotropes 0.5 0.5 Requiring transfusion (≥4 units) 1.2 1.0 Other major bleeding 1.6 1.0 Significantly disabling 0.4 0.3 Intraocular bleeding with significant loss of vision 0.05 0.03 Requiring 2 to 3 units of blood 1.3 0.9 Minor bleeding † 5.1 2.4 * Life-threatening and other major bleeding. † Led to interruption of study medication. COMMIT In COMMIT, similar rates of major bleeding were observed in the clopidogrel and placebo groups, both of which also received aspirin (see Table 2). Table 2: Incidence of Bleeding Events in COMMIT (% patients) Type of Bleeding Clopidogrel (+ aspirin) (n=22961) Placebo (+ aspirin) (n=22891) p-value Major* noncerebral or cerebral bleeding 0.6 0.5 0.59 Major noncerebral 0.4 0.3 0.48 Fatal 0.2 0.2 0.90 Hemorrhagic stroke 0.2 0.2 0.91 Fatal 0.2 0.2 0.81 Other noncerebral bleeding (nonmajor) 3.6 3.1 0.005 Any noncerebral bleeding 3.9 3.4 0.004 * Major bleeds were cerebral bleeds or noncerebral bleeds thought to have caused death or that required transfusion. CAPRIE (Clopidogrel vs Aspirin) In CAPRIE, gastrointestinal hemorrhage occurred at a rate of 2.0% in those taking clopidogrel versus 2.7% in those taking aspirin; bleeding requiring hospitalization occurred in 0.7% and 1.1%, respectively. The incidence of intracranial hemorrhage was 0.4% for clopidogrel compared to 0.5% for aspirin. Other bleeding events that were reported more frequently in the clopidogrel group were epistaxis and hematoma. Other Adverse Events In CURE and CHARISMA, which compared clopidogrel plus aspirin to aspirin alone, there was no difference in the rate of adverse events (other than bleeding) between clopidogrel and placebo. In CAPRIE, which compared clopidogrel to aspirin, pruritus was more frequently reported in those taking clopidogrel. No other difference in the rate of adverse events (other than bleeding) was reported. 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of clopidogrel. Because these reactions are reported voluntarily from a population of an unknown size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Hemorrhages, including those with fatal outcome, have been reported in patients treated with clopidogrel. • Blood and lymphatic system disorders: Agranulocytosis, aplastic anemia/pancytopenia, thrombotic thrombocytopenic purpura (TTP), acquired hemophilia A • Gastrointestinal disorders: Colitis (including ulcerative or lymphocytic colitis), pancreatitis, stomatitis, gastric/duodenal ulcer, diarrhea • General disorders and administration site condition: Fever • Hepatobiliary disorders: Acute liver failure, hepatitis (noninfectious), abnormal liver function test • Immune system disorders: Hypersensitivity reactions, anaphylactoid reactions, serum sickness, insulin autoimmune syndrome, which can lead to severe hypoglycemia. • Musculoskeletal, connective tissue and bone disorders: Myalgia, arthralgia, arthritis • Nervous system disorders: Taste disorders, headache, ageusia • Psychiatric disorders: Confusion, hallucinations • Respiratory, thoracic and mediastinal disorders: Bronchospasm, interstitial pneumonitis, eosinophilic pneumonia • Renal and urinary disorders: Increased creatinine levels • Skin and subcutaneous tissue disorders: Maculopapular, erythematous or exfoliative rash, urticaria, bullous dermatitis, eczema, toxic epidermal necrolysis, Stevens-Johnson syndrome, acute generalized exanthematous pustulosis (AGEP), angioedema, drug-induced hypersensitivity syndrome, drug rash with eosinophilia and systemic symptoms (DRESS), erythema multiforme, lichen planus, generalized pruritus • Vascular disorders: Vasculitis, hypotension

12.3 Pharmacokinetics Clopidogrel is a prodrug and is metabolized to a pharmacologically active metabolite and inactive metabolites. Absorption After single and repeated oral doses of 75 mg per day, clopidogrel is rapidly absorbed. Absorption is at least 50%, based on urinary excretion of clopidogrel metabolites. Effect of food Clopidogrel tablets can be administered with or without food. In a study in healthy male subjects when clopidogrel tablet 75 mg per day was given with a standard breakfast, mean inhibition of ADP-induced platelet aggregation was reduced by less than 9%. The active metabolite AUC 0-24 was unchanged in the presence of food, while there was a 57% decrease in active metabolite C max . Similar results were observed when a clopidogrel tablet 300 mg loading dose was administered with a high-fat breakfast. Metabolism Clopidogrel is extensively metabolized by two main metabolic pathways: one mediated by esterases and leading to hydrolysis into an inactive carboxylic acid derivative (85% of circulating metabolites) and one mediated by multiple cytochrome P450 enzymes. Cytochromes first oxidize clopidogrel to a 2-oxo-clopidogrel intermediate metabolite. Subsequent metabolism of the 2-oxo-clopidogrel intermediate metabolite results in formation of the active metabolite, a thiol derivative of clopidogrel. The active metabolite is formed mostly by CYP2C19 with contributions from several other CYP enzymes, including CYP1A2, CYP2B6 and CYP3A. The active thiol metabolite binds rapidly and irreversibly to platelet receptors, thus inhibiting platelet aggregation for the lifespan of the platelet. The C max of the active metabolite is twice as high following a single 300 mg clopidogrel loading dose as it is after four days of 75 mg maintenance dose. C max occurs approximately 30 to 60 minutes after dosing. In the 75 to 300 mg dose range, the pharmacokinetics of the active metabolite deviates from dose proportionality: 4-fold the dose results in 2.0-fold and 2.7-fold the C max and AUC, respectively. Elimination Following an oral dose of 14 C-labeled clopidogrel in humans, approximately 50% of total radioactivity was excreted in urine and approximately 46% in feces over the 5 days post dosing. After a single, oral dose of 75 mg, clopidogrel has a half-life of approximately 6 hours. The half-life of the active metabolite is about 30 minutes. Drug Interactions Effect of other drugs on Clopidogrel Clopidogrel is metabolized to its active metabolite in part by CYP2C19. CYP2C19 inducers Concomitant use of strong inducers of CYP2C19 results in increased plasma concentration of the active metabolite of clopidogrel and an increase in platelet inhibition. Rifampin: Coadministration of rifampin 300 mg twice daily for 7 days with 600 mg loading dose of clopidogrel in healthy adults increased the mean AUC and C max of clopidogrel’s thiol metabolites by 3.8-fold. Mean inhibition of platelet aggregation at 4 hours post dose was 34% higher in the presence of rifampin compared to clopidogrel administered alone. CYP2C19 inhibitors Concomitant use of certain inhibitors of this enzyme results in reduced plasma concentrations of the active metabolite of clopidogrel and a reduction in platelet inhibition. Proton pump inhibitors (PPI) The effect of proton pump inhibitors (PPI) on the systemic exposure to the clopidogrel active metabolite following multiple doses of clopidogrel tablets 75 mg evaluated in dedicated drug interaction studies is presented in Figure 1. Figure 1: Exposure to Clopidogrel Active Metabolite Following Multiple Doses of Clopidogrel Tablets, 75 mg Alone or with Proton Pump Inhibitors (PPIs) Pharmacodynamic and pharmacokinetic parameters measured in these studies showed that the interaction was highest with omeprazole and least with dexlansoprazole. Opioids Coadministration of 5 mg intravenous morphine with 600 mg loading dose of clopidogrel in healthy adults decreased the AUC and C max of clopidogrel's thiol metabolites by 34%. Mean platelet aggregation was higher up to 2 to 4 hours with morphine coadministration. Effect of Clopidogrel on other drugs In vitro studies have shown that the glucuronide metabolite of clopidogrel is a strong inhibitor of CYP2C8. Concomitant administration of repaglinide with clopidogrel increased the systemic exposure to repaglinide (AUC 0-∞ ) by 5.1-fold following the loading dose (300 mg) and by 3.9-fold on day 3 of the maintenance dose (75 mg) of clopidogrel [ see Drug Interactions ( 7.8 ) ]. figure-1