Clopidogrel

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 ) 7.1 CYP2C19 Inducers Since clopidogrel is metabolized to its active metabolite partly by CYP2C19, use of drugs that induce the activity of this enzyme would be expected to result in increased drug levels of the active metabolite of clopidogrel. Rifampin strongly induces CYP2C19 resulting to both an increase level of clopidogrel active metabolite and platelet inhibition, which in particular might potentiate the risk of bleeding. As a precaution, avoid concomitant use of strong CYP2C19 inducers [ see Warnings and Precautions ( 5.1 ) and Clinical Pharmacology ( 12.3 )]. 7.2 CYP2C19 Inhibitors Clopidogrel is metabolized to its active metabolite in part by CYP2C19. Concomitant use of drugs that inhibit the activity of this enzyme results in reduced plasma concentrations of the active metabolite of clopidogrel and a reduction in platelet inhibition [ see Warnings and Precautions ( 5.1 ) ]. Omeprazole or Esomeprazole Avoid concomitant use of clopidogrel with omeprazole or esomeprazole. In clinical studies, omeprazole was shown to reduce significantly the antiplatelet activity of clopidogrel when given concomitantly or 12 hours apart. A similar reduction in antiplatelet activity was observed with esomeprazole when given concomitantly with clopidogrel. Dexlansoprazole, lansoprazole, and pantoprazole had less effect on the antiplatelet activity of clopidogrel than did omeprazole or esomeprazole [ see Warnings and Precautions ( 5.1 ) and Clinical Pharmacology ( 12.3 ) ]. 7.3 Opioids As with other oral P2Y 12 inhibitors, coadministration of opioid agonists delay and reduce the absorption of clopidogrel, presumably because of slowed gastric emptying, resulting in reduced exposure to its metabolites [ see Clinical Pharmacology ( 12.3 ) ]. Consider the use of a parenteral antiplatelet agent in acute coronary syndrome patients requiring coadministration of morphine or other opioid agonists. 7.4 Nonsteroidal Anti-inflammatory Drugs (NSAIDs) Coadministration of clopidogrel and NSAIDs increases the risk of gastrointestinal bleeding. 7.5 Warfarin (CYP2C9 Substrates) Although the administration of clopidogrel 75 mg per day did not modify the pharmacokinetics of S-warfarin (a CYP2C9 substrate) or INR in patients receiving long-term warfarin therapy, coadministration of clopidogrel with warfarin increases the risk of bleeding because of independent effects on hemostasis. However, at high concentrations in vitr o, clopidogrel inhibits CYP2C9. 7.6 SSRIs and SNRIs Since selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) affect platelet activation, the concomitant administration of SSRIs and SNRIs with clopidogrel may increase the risk of bleeding. 7.7 Other Antiplatelet Agents Coadministration of antiplatelet agents increase the risk of bleeding due to an additive effect. Promptly evaluate any signs or symptoms of blood loss if patients are treated concomitantly with other antiplatelet agents [see Warnings and Precautions ( 5.2 )]. 7.8 Repaglinide (CYP2C8 Substrates) The acyl-β-glucuronide metabolite of clopidogrel is a strong inhibitor of CYP2C8. Clopidogrel can increase the systemic exposure to drugs that are primarily cleared by CYP2C8, thereby needing dose adjustment and appropriate monitoring. Clopidogrel increased repaglinide exposures by 3.9-fold to 5.1-fold [see Clinical Pharmacology ( 12.3 )] . Avoid concomitant use of repaglinide with clopidogrel. If concomitant use cannot be avoided, initiate repaglinide at 0.5 mg before each meal and do not exceed a total daily dose of 4 mg. Increased frequency of glucose monitoring may be required during concomitant use.

Clopidogrel is indicated to reduce cardiovascular events in patients with: - Acute Coronary Syndrome (ACS): Non-ST-segment elevation ACS (unstable angina/NSTEMI) and ST-elevation MI, administered with aspirin - Secondary Prevention: Recent MI, recent stroke, or established peripheral arterial disease

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 ) ].

Most Significant: "Bleeding, including life-threatening and fatal bleeding, is the most commonly reported adverse reaction." CURE Trial Major Bleeding: 3.7% (clopidogrel + aspirin) vs. 2.7% (placebo + aspirin) Other Common Events: Epistaxis, hematuria, bruising, GI hemorrhage Postmarketing: TTP, agranulocytosis, rash/angioedema, hepatitis, pancreatitis