Clopidogrel Drug Information

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 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 .

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) * Life-threatening and other major bleeding. † Led to interruption of study medication.

Major bleeding * 3.7

Requiring transfusion (≥4 units) 1.2 1 Other major bleeding 1.6 1 Significantly

disabling 0.4

Intraocular bleeding with significant loss of vision 0.05 0.03 Requiring 2 to

3 units of blood 1.3

Minor bleeding † 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 bleeds were cerebral bleeds or noncerebral bleeds thought to have caused death or that required transfusion. 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 CAPRIE (Clopidogrel vs Aspirin) In CAPRIE, gastrointestinal hemorrhage occurred at a rate of 2% 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.

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

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 .

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 . 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.

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 . Consider the use of a parenteral antiplatelet agent in acute coronary syndrome patients requiring coadministration of morphine or other opioid agonists.

Nonsteroidal Anti-inflammatory Drugs (NSAIDs) Coadministration of clopidogrel and

NSAIDs increases the risk of gastrointestinal bleeding.

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.

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.

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 .

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 . 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.

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. There are risks to the pregnant woman and fetus associated with myocardial infarction and stroke . 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 . 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 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.

Active Bleeding Clopidogrel tablets are contraindicated in patients with active pathological bleeding

such as peptic ulcer or intracranial hemorrhage.

Hypersensitivity Clopidogrel tablets are contraindicated in patients with hypersensitivity (e.g., anaphylaxis) to

clopidogrel or any component of the product .

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.