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Clopidogrel Bisulfate

Rx Oral RxCUI 309362
Contents

Overview

Active ingredient
Clopidogrel Bisulfate
Route
Oral
Label date
2023-11-08

Boxed 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 metabolizers”). Tests are available to identify patients who are CYP2C19 poor metabolizers [see Clinical Pharmacology (12.5) ] . Consider use of another platelet P2Y 12 inhibitor in patients identified as CYP2C19 poor metabolizers. WARNING: DIMINISHED ANTIPLATELET EFFECT IN PATIENTS WITH TWO LOSS-OF-FUNCTION ALLELES OF THE CYP2C19 GENE See full prescribing information for complete boxed warning. Effectiveness of clopidogrel depends on conversion to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19. ( 5.1 , 12.3 ) Tests are available to identify patients who are CYP2C19 poor metabolizers. ( 12.5 ) Consider use of another platelet P2Y 12 inhibitor in patients identified as CYP2C19 poor metabolizers. ( 5.1 )

Indications and 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.

Dosage and 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) ] .

Dosage forms and strengths

Clopidogrel Tablets, USP 75 mg tablets: Pink colored, Round shaped, biconvex, film coated tablets de-bossed on one side with SG and 124 on other side. Clopidogrel Tablets, USP 300 mg tablets: Pink colored, Modified oval shaped, film coated tablets de-bossed on one side with SG and 121 on other side. Tablets: 75 mg, 300 mg ( 3 )

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 is contraindicated in patients with active pathological bleeding such as peptic ulcer or intracranial hemorrhage.

4.2 Hypersensitivity Clopidogrel is contraindicated in patients with hypersensitivity (e.g., anaphylaxis) to clopidogrel or any component of the product [see Adverse Reactions (6.2) ] .

Warnings and precautions

5 WARNINGS AND PRECAUTIONS ­ CYP2C19 inhibitors: Avoid concomitant use of omeprazole or esomeprazole. (5.1) Bleeding: Clopidogrel increases risk of bleeding. (5.2) Discontinuation: Premature discontinuation increases risk of cardiovascular events. Discontinue 5 days prior to elective surgery that has a major risk of bleeding. (5.3) Thrombotic thrombocytopenic purpura (TTP) has been reported. (5.4) Cross-reactivity among thienopyridines has been reported. (5.5)

5.1 Diminished Antiplatelet Activity in Patients with Impaired CYP2C19 Function Clopidogrel is a prodrug. Inhibition of platelet aggregation by clopidogrel is achieved through an active metabolite. The metabolism of clopidogrel to its active metabolite can be impaired by genetic variations in CYP2C19 [see Boxed Warning ] . The metabolism of clopidogrel can also be impaired by drugs that inhibit CYP2C19, such as omeprazole or esomeprazole. Avoid concomitant use of clopidogrel with omeprazole or esomeprazole because both significantly reduce the antiplatelet activity of clopidogrel [see Drug Interactions (7.1) ].

5.2 General Risk of Bleeding P2Y12 inhibitors (thienopyridines), including clopidogrel, increase the risk of bleeding. P2Y12 inhibitors (thienopyridines), inhibit platelet aggregation for the lifetime of the platelet (7-10 days). Because the half-life of clopidogrel’s active metabolite is short, it may be possible to restore hemostasis by administering exogenous platelets; however, platelet transfusions within 4 hours of the loading dose or 2 hours of the maintenance dose may be less effective. Use of drugs that induce the activity of CYP2C19 would be expected to result in increased drug levels of the active metabolite of clopidogrel and might potentiate the bleeding risk. As a precaution, avoid concomitant use of strong CYP2C19 inducers [see Drug Interactions (7.1) and Clinical Pharmacology (12.3) ] . Risk factors for bleeding include concomitant use of other drugs that increase the risk of bleeding (e.g., anticoagulants, antiplatelet agents, and chronic use of NSAIDs) [see Drug Interactions (7.4 , 7.5 , 7.6 , 7.7 )] .

5.3 Discontinuation of Clopidogrel Discontinuation of clopidogrel increases the risk of cardiovascular events. If clopidogrel must be temporarily discontinued (e.g., to treat bleeding or for surgery with a major risk of bleeding), restart it as soon as possible. When possible, interrupt therapy with clopidogrel for five days prior to such surgery. Resume clopidogrel as soon as hemostasis is achieved.

5.4 Thrombotic Thrombocytopenic Purpura (TTP) TTP, sometimes fatal, has been reported following use of clopidogrel, sometimes after a short exposure (<2 weeks). TTP is a serious condition that requires urgent treatment including plasmapheresis (plasma exchange). It is characterized by thrombocytopenia, microangiopathic hemolytic anemia (schistocytes [fragmented RBCs] seen on peripheral smear), neurological findings, renal dysfunction, and fever [see Adverse Reactions (6.2) ] .

5.5 Cross-Reactivity among Thienopyridines Hypersensitivity including rash, angioedema or hematologic reaction has been reported in patients receiving clopidogrel, including patients with a history of hypersensitivity or hematologic reaction to other thienopyridines [ see Contraindications (4.2) and Adverse Reactions (6.2) ].

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, co-administration 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 co-administration 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 vitro, 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.

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 ScieGen Pharmaceuticals Inc at 1-855-724-3436 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) (n=6259) Placebo (+ aspirin) (n=6303) Major bleeding Life-threatening and other 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 2-3 units of blood 1.3 0.9 Minor bleeding Led to interruption of study medication 5.1 2.4 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 Major bleeds were cerebral bleeds or noncerebral bleeds thought to have caused death or that required transfusion. 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 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

Overdosage

Platelet inhibition by clopidogrel is irreversible and will last for the life of the platelet. Overdose following clopidogrel administration may result in bleeding complications. A single oral dose of clopidogrel at 1500 or 2000 mg/kg was lethal to mice and to rats and at 3000 mg/kg to baboons. Symptoms of acute toxicity were vomiting, prostration, difficult breathing, and gastrointestinal hemorrhage in animals. Based on biological plausibility, platelet transfusion may restore clotting ability.

Use in specific populations

8.1 Pregnancy Risk Summary Available data from cases reported in published literature and postmarketing surveillance with clopidogrel use in pregnant women have not identified any drug-associated risks for major birth defects or miscarriage [see Data ]. There are risks to the pregnant woman and fetus associated with myocardial infarction and stroke [see Clinical Considerations ]. No evidence of fetotoxicity was observed when clopidogrel was administered to pregnant rats and rabbits during organogenesis at doses corresponding to 65 and 78 times the recommended daily human dose [see Data ]. The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Myocardial infarction and stroke are medical emergencies. Therapy for the pregnant woman should not be withheld because of potential concerns regarding the effects of clopidogrel on the fetus. Labor or delivery Clopidogrel use during labor or delivery will increase the risk of maternal bleeding and hemorrhage. Avoid neuraxial blockade during clopidogrel use because of the risk of spinal hematoma. When possible, discontinue clopidogrel 5 to 7 days prior to labor, delivery, or neuraxial blockade. Data Human Data The available data from published case reports over two decades of postmarketing use have not identified an association with clopidogrel use in pregnancy and major birth defects, miscarriage, or adverse fetal outcomes. Animal data Embryo-fetal developmental toxicology studies were performed in pregnant rats and rabbits with doses up to 500 mg/kg/day and 300 mg/kg/day, respectively, administered during organogenesis. These doses, corresponding to 65 and 78 times the recommended daily human dose, respectively, on a mg/m 2 basis, revealed no evidence of impaired fertility or fetotoxicity due to clopidogrel.

8.2 Lactation Risk Summary There are no data on the presence of clopidogrel in human milk or the effects on milk production. No adverse effects on breastfed infants have been observed with maternal clopidogrel use during lactation in a small number of postmarketing cases. Studies in rats have shown that clopidogrel and/or its metabolites are present in the milk. When a drug is present in animal milk, it is likely that the drug will be present in human milk. The developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for clopidogrel and any potential adverse effects on the breastfed infant from clopidogrel or from underlying maternal condition.

8.4 Pediatric Use Safety and effectiveness in pediatric populations have not been established. A randomized, placebo-controlled trial (CLARINET) did not demonstrate a clinical benefit of clopidogrel in neonates and infants with cyanotic congenital heart disease palliated with a systemic-to-pulmonary arterial shunt. Possible factors contributing to this outcome were the dose of clopidogrel, the concomitant administration of aspirin, and the late initiation of therapy following shunt palliation. It cannot be ruled out that a trial with a different design would demonstrate a clinical benefit in this patient population.

8.5 Geriatric Use Of the total number of subjects in the CAPRIE and CURE controlled clinical studies, approximately 50% of patients treated with clopidogrel were 65 years of age and older, and 15% were 75 years and older. In COMMIT, approximately 58% of the patients treated with clopidogrel were 60 years and older, 26% of whom were 70 years and older. The observed risk of bleeding events with clopidogrel plus aspirin versus placebo plus aspirin by age category is provided in Table 1 and Table 2 for the CURE and COMMIT trials, respectively [see Adverse Reactions (6.1) ] . No dosage adjustment is necessary in elderly patients.

8.6 Renal Impairment Experience is limited in patients with severe and moderate renal impairment [see Clinical Pharmacology (12.2) ] .

8.7 Hepatic Impairment No dosage adjustment is necessary in patients with hepatic impairment [see Clinical Pharmacology (12.2) ] .

Pregnancy

Risk Summary Available data from cases reported in published literature and postmarketing surveillance with clopidogrel use in pregnant women have not identified any drug-associated risks for major birth defects or miscarriage [see Data ]. There are risks to the pregnant woman and fetus associated with myocardial infarction and stroke [see Clinical Considerations ]. No evidence of fetotoxicity was observed when clopidogrel was administered to pregnant rats and rabbits during organogenesis at doses corresponding to 65 and 78 times the recommended daily human dose [see Data ]. The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Myocardial infarction and stroke are medical emergencies. Therapy for the pregnant woman should not be withheld because of potential concerns regarding the effects of clopidogrel on the fetus. Labor or delivery Clopidogrel use during labor or delivery will increase the risk of maternal bleeding and hemorrhage. Avoid neuraxial blockade during clopidogrel use because of the risk of spinal hematoma. When possible, discontinue clopidogrel 5 to 7 days prior to labor, delivery, or neuraxial blockade. Data Human Data The available data from published case reports over two decades of postmarketing use have not identified an association with clopidogrel use in pregnancy and major birth defects, miscarriage, or adverse fetal outcomes. Animal data Embryo-fetal developmental toxicology studies were performed in pregnant rats and rabbits with doses up to 500 mg/kg/day and 300 mg/kg/day, respectively, administered during organogenesis. These doses, corresponding to 65 and 78 times the recommended daily human dose, respectively, on a mg/m 2 basis, revealed no evidence of impaired fertility or fetotoxicity due to clopidogrel.

Pediatric use

Safety and effectiveness in pediatric populations have not been established. A randomized, placebo-controlled trial (CLARINET) did not demonstrate a clinical benefit of clopidogrel in neonates and infants with cyanotic congenital heart disease palliated with a systemic-to-pulmonary arterial shunt. Possible factors contributing to this outcome were the dose of clopidogrel, the concomitant administration of aspirin, and the late initiation of therapy following shunt palliation. It cannot be ruled out that a trial with a different design would demonstrate a clinical benefit in this patient population.

Geriatric use

Of the total number of subjects in the CAPRIE and CURE controlled clinical studies, approximately 50% of patients treated with clopidogrel were 65 years of age and older, and 15% were 75 years and older. In COMMIT, approximately 58% of the patients treated with clopidogrel were 60 years and older, 26% of whom were 70 years and older. The observed risk of bleeding events with clopidogrel plus aspirin versus placebo plus aspirin by age category is provided in Table 1 and Table 2 for the CURE and COMMIT trials, respectively [see Adverse Reactions (6.1) ] . No dosage adjustment is necessary in elderly patients.

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 empirical formula of clopidogrel bisulfate is C 16 H 16 ClNO 2 S

  • H 2 SO 4 and its molecular weight is 419.9. The structural formula is as follows: Clopidogrel bisulfate, USP is a white to off-white powder. It is freely soluble in methanol, practically insoluble in ether. It has a specific optical rotation of about +56°. Clopidogrel for oral administration is provided as either pink colored, round shaped, biconvex, de-bossed, film coated tablets containing 97.875 mg of clopidogrel bisulfate which is the molar equivalent of 75 mg of clopidogrel base or pink colored, modified oval shaped, de-bossed film coated tablets containing 391.5 mg of clopidogrel bisulfate which is the molar equivalent of 300 mg of clopidogrel base. Each tablet contains microcrystalline cellulose, mannitol, croscarmellose sodium, hydroxy propyl cellulose, hydroxy propyl methyl cellulose and hydrogenated castor oil as inactive ingredients. The film coating contains hypromellose, titanium dioxide, polyethylene glycol, red iron oxide and yellow iron oxide. structure

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). Platelet aggregation induced by agonists other than ADP is also inhibited by blocking the amplification of platelet activation by released ADP. Dose-dependent inhibition of platelet aggregation can be seen 2 hours after single oral doses of clopidogrel. Repeated doses of 75 mg clopidogrel per day inhibit ADP-induced platelet aggregation on the first day, and inhibition reaches steady state between Day 3 and Day 7. At steady state, the average inhibition level observed with a dose of 75 mg clopidogrel per day was between 40% and 60%. Platelet aggregation and bleeding time gradually return to baseline values after treatment is discontinued, generally in about 5 days. Geriatric Patients Elderly (≥75 years) and young healthy subjects had similar effects on platelet aggregation. Renally Impaired Patients After repeated doses of 75 mg clopidogrel per day, patients with severe renal impairment (creatinine clearance from 5 to 15 mL/min) and moderate renal impairment (creatinine clearance from 30 to 60 mL/min) showed low (25%) inhibition of ADP-induced platelet aggregation. Hepatically Impaired Patients After repeated doses of 75 mg clopidogrel per day for 10 days in patients with severe hepatic impairment, inhibition of ADP-induced platelet aggregation was similar to that observed in healthy subjects. Gender In a small study comparing men and women, less inhibition of ADP-induced platelet aggregation was observed in women.

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 can be administered with or without food. In a study in healthy male subjects when clopidogrel 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 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 contribution 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 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 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 Co-administration 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 co-administration. 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 (7.6 )] . figure1 12.5 Pharmacogenomics CYP2C19 is involved in the formation of both the active metabolite and the 2-oxo-clopidogrel intermediate metabolite. Clopidogrel active metabolite pharmacokinetics and antiplatelet effects, as measured by ex vivo platelet aggregation assays, differ according to CYP2C19 genotype. Patients who are homozygous for nonfunctional alleles of the CYP2C19 gene are termed “CYP2C19 poor metabolizers.” Approximately 2% of White and 4% of Black patients are poor metabolizers; the prevalence of poor metabolism is higher in Asian patients (e.g., 14% of Chinese). Tests are available to identify patients who are CYP2C19 poor metabolizers. A crossover study in 40 healthy subjects, 10 each in the four CYP2C19 metabolizer groups, evaluated pharmacokinetic and antiplatelet responses using 300 mg followed by 75 mg per day and 600 mg followed by 150 mg per day, each for a total of 5 days. Decreased active metabolite exposure and diminished inhibition of platelet aggregation were observed in the poor metabolizers as compared to the other groups. Table 3: Active Metabolite Pharmacokinetics and Antiplatelet Responses by CYP2C19 Metabolizer Status Dose Poor (n=10) Intermediate Intermediate metabolizers have one but not two nonfunctional alleles. (n=10) Normal (n=10) Ultrarapid Ultrarapid metabolizers have at least one gain-of-function allele. (n=10) C max (ng/mL) 300 mg (24 h) 11 (4) 23 (11) 32 (21) 24 (10) 600 mg (24 h) 17 (6) 39 (23) 44 (27) 36 (13) 75 mg (Day 5) 4 (1) 12 (5) 13 (7) 12 (6) 150 mg (Day 5) 7 (2) 18 (7) 19 (5) 16 (9) IPA (%) Inhibition of platelet aggregation with 5 mcM ADP; larger value indicates greater platelet inhibition. 300 mg (24 h) 24 (26) 37 (21) 39 (28) 40 (21) 600 mg (24 h) 32 (25) 56 (22) 49 (23) 51 (28) 75 mg (Day 5) 37 (23) 60 (18) 58 (19) 56 (13) 150 mg (Day 5) 61 (14) 74 (14) 73 (9) 68 (18) VASP-PRI (%) Vasodilator-stimulated phosphoprotein – platelet reactivity index; smaller value indicates greater platelet inhibition. Values are mean (SD). 300 mg (24 h) 91 (12) 78 (12) 68 (16) 73 (12) 600 mg (24 h) 85 (14) 56 (26) 48 (20) 51 (20) 75 mg (Day 5) 83 (13) 50 (16) 39 (14) 40 (9) 150 mg (Day 5) 61 (18) 29 (11) 24 (10) 20 (10)

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.

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). Platelet aggregation induced by agonists other than ADP is also inhibited by blocking the amplification of platelet activation by released ADP. Dose-dependent inhibition of platelet aggregation can be seen 2 hours after single oral doses of clopidogrel. Repeated doses of 75 mg clopidogrel per day inhibit ADP-induced platelet aggregation on the first day, and inhibition reaches steady state between Day 3 and Day 7. At steady state, the average inhibition level observed with a dose of 75 mg clopidogrel per day was between 40% and 60%. Platelet aggregation and bleeding time gradually return to baseline values after treatment is discontinued, generally in about 5 days. Geriatric Patients Elderly (≥75 years) and young healthy subjects had similar effects on platelet aggregation. Renally Impaired Patients After repeated doses of 75 mg clopidogrel per day, patients with severe renal impairment (creatinine clearance from 5 to 15 mL/min) and moderate renal impairment (creatinine clearance from 30 to 60 mL/min) showed low (25%) inhibition of ADP-induced platelet aggregation. Hepatically Impaired Patients After repeated doses of 75 mg clopidogrel per day for 10 days in patients with severe hepatic impairment, inhibition of ADP-induced platelet aggregation was similar to that observed in healthy subjects. Gender In a small study comparing men and women, less inhibition of ADP-induced platelet aggregation was observed in women.

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 can be administered with or without food. In a study in healthy male subjects when clopidogrel 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 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 contribution 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 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 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 Co-administration 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 co-administration. 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 (7.6 )] . figure1

Carcinogenesis, mutagenesis, fertility

, Mutagenesis, Impairment of Fertility There was no evidence of tumorigenicity when clopidogrel was administered for 78 weeks to mice and 104 weeks to rats at dosages up to 77 mg/kg per day, which afforded plasma exposures >25 times that in humans at the recommended daily dose of 75 mg. Clopidogrel was not genotoxic in four in vitro tests (Ames test, DNA-repair test in rat hepatocytes, gene mutation assay in Chinese hamster fibroblasts, and metaphase chromosome analysis of human lymphocytes) and in one in vivo test (micronucleus test by oral route in mice). Clopidogrel was found to have no effect on fertility of male and female rats treated prior to pairing and throughout gestation at oral doses up to 400 mg/kg per day (52 times the recommended human dose on a mg/m 2 basis).

Information for patients

17 PATIENT COUNSELING INFORMATION Advise patients to read FDA approved patient labeling ( Medication Guide ). Discontinuation Advise patients not to discontinue clopidogrel without first discussing it with the healthcare provider who prescribed it [see Warnings and Precautions (5.3) ] . Bleeding Advise patients that they: will bruise and bleed more easily. will take longer than usual to stop bleeding. must report any unanticipated, prolonged, or excessive bleeding, or blood in their stool or urine [see Warnings and Precautions (5.2) ] Thrombotic Thrombocytopenic Purpura Instruct patients to get prompt medical attention if they experience symptoms of TTP that cannot otherwise be explained [see Warnings and Precautions (5.4) ] . Invasive Procedures Advise patients to inform physicians and dentists that they are taking clopidogrel before any surgery or dental procedure [see Warnings and Precautions (5.2 , 5.3) ] . Proton Pump Inhibitors Advise patients not to take omeprazole or esomeprazole while taking clopidogrel. Dexlansoprazole, lansoprazole and pantoprazole had less pronounced effects on the antiplatelet activity of clopidogrel than did omeprazole or esomeprazole [see Drug Interactions (7.1) ] . The brands listed are trademarks of their respective owners and are not trademarks of ScieGen Pharmaceuticals, Inc. The makers of these brands are not affiliated with and do not endorse ScieGen Pharmaceuticals, Inc., or its products. Manufactured by: ScieGen Pharmaceuticals, Inc. Hauppauge, NY 11788 USA Distributed by: Radha Pharmaceuticals, Inc. Hauppauge, NY 11788 USA Dispense the Medication Guide available at: https://radhapharm.com/medication-guide/ Rev. 8/2023