1.1 Acute Coronary Syndrome (ACS)

• For 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, Plavix has been shown to decrease the rate of a combined endpoint of cardiovascular death, myocardial infarction (MI), or stroke as well as the rate of a combined endpoint of cardiovascular death, MI, stroke, or refractory ischemia.
• For patients with ST-elevation myocardial infarction (STEMI), Plavix has been shown to reduce the rate of death from any cause and the rate of a combined endpoint of death, re-infarction, or stroke. The benefit for patients who undergo primary percutaneous coronary intervention is unknown.

The optimal duration of Plavix therapy in ACS is unknown.

1.2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease

For patients with a history of recent myocardial infarction (MI), recent stroke, or established peripheral arterial disease, Plavix has been shown to reduce the rate of a combined endpoint of new ischemic stroke (fatal or not), new MI (fatal or not), and other vascular death.

2.1Acute Coronary Syndrome

Plavix can be administered with or without food [see Clinical Pharmacology (12.3)].

• For patients with non-ST-elevation ACS (UA/NSTEMI), initiate Plavix with a single 300 mg oral loading dose and then continue at 75 mg once daily. Initiate aspirin (75–325 mg once daily) and continue in combination with Plavix [see Clinical Studies (14.1)].
• For patients with STEMI, the recommended dose of Plavix is 75 mg once daily orally, administered in combination with aspirin (75–325 mg once daily), with or without thrombolytics. Plavix may be initiated with or without a loading dose [see Clinical Studies (14.1)].

2.2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease

The recommended daily dose of Plavix is 75 mg once daily orally, with or without food [see Clinical Pharmacology (12.3)].

2.3 CYP2C19 Poor Metabolizers

CYP2C19 poor metabolizer status is associated with diminished antiplatelet response to clopidogrel. Although a higher dose regimen in poor metabolizers increases antiplatelet response [see Clinical Pharmacology (12.5)], an appropriate dose regimen for this patient population has not been established.

2.4 Use with Proton Pump Inhibitors (PPI)

Omeprazole, a moderate CYP2C19 inhibitor, reduces the pharmacological activity of Plavix. Avoid using omeprazole concomitantly or 12 hours apart with Plavix. Consider using another acid-reducing agent with less CYP2C19 inhibitory activity. A higher dose regimen of clopidogrel concomitantly administered with omeprazole increases antiplatelet response; an appropriate dose regimen has not been established [see Warnings and Precautions (5.1), Drug Interactions (7.1) and Clinical Pharmacology (12.5)].

4.1 Active Bleeding

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

4.2 Hypersensitivity

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

5.1 Diminished Antiplatelet Activity Due to Impaired CYP2C19 Function

Clopidogrel is a prodrug. Inhibition of platelet aggregation by clopidogrel is due to an active metabolite. The metabolism of clopidogrel to its active metabolite can be impaired by genetic variations in CYP2C19 [see Boxed Warning] and by concomitant medications that interfere with CYP2C19. Avoid concomitant use of Plavix and strong or moderate CYP2C19 inhibitors.

Omeprazole, a moderate CYP2C19 inhibitor, has been shown to reduce the pharmacological activity of Plavix if given concomitantly or if given 12 hours apart. Consider using another acid-reducing agent with less CYP2C19 inhibitory activity. Pantoprazole, a weak CYP2C19 inhibitor, had less effect on the pharmacological activity of Plavix than omeprazole [see Drug Interactions (7.1) and Dosage and Administration (2.4)].

5.2 General Risk of Bleeding

Thienopyridines, including Plavix, increase the risk of bleeding. If a patient is to undergo surgery and an antiplatelet effect is not desired, discontinue Plavix five days prior to surgery. In patients who stopped therapy more than five days prior to CABG the rates of major bleeding were similar (event rate 4.4% Plavix + aspirin; 5.3% placebo + aspirin). In patients who remained on therapy within five days of CABG, the major bleeding rate was 9.6% for Plavix + aspirin, and 6.3% for placebo + aspirin.

Thienopyridines inhibit platelet aggregation for the lifetime of the platelet (7–10 days), so withholding a dose will not be useful in managing a bleeding event or the risk of bleeding associated with an invasive procedure. 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.

5.3 Discontinuation of Plavix

Avoid lapses in therapy, and if Plavix must be temporarily discontinued, restart as soon as possible. Premature discontinuation of Plavix may increase the risk of cardiovascular events.

5.4 Patients with Recent Transient Ischemic Attack (TIA) or Stroke

In patients with recent TIA or stroke who are at high risk for recurrent ischemic events, the combination of aspirin and Plavix has not been shown to be more effective than Plavix alone, but the combination has been shown to increase major bleeding.

5.5 Thrombotic Thrombocytopenic Purpura (TTP)

TTP, sometimes fatal, has been reported following use of Plavix, 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)].

6.1 Clinical Studies 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.

Plavix has been eva luated for safety in more than 54,000 patients, including over 21,000 patients treated for 1 year or more. The clinically important adverse reactions observed in trials comparing Plavix plus aspirin to placebo plus aspirin and trials comparing Plavix alone to aspirin alone are discussed below.

Bleeding

CURE

In CURE, Plavix 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.

Ninety-two percent (92%) of the patients in the CURE study received heparin or low molecular weight heparin (LMWH), and the rate of bleeding in these patients was similar to the overall results.

COMMIT

In COMMIT, similar rates of major bleeding were observed in the Plavix and placebo groups, both of which also received aspirin (see Table 2).

CAPRIE (Plavix vs. Aspirin)

In CAPRIE, gastrointestinal hemorrhage occurred at a rate of 2.0% in those taking Plavix vs. 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 Plavix compared to 0.5% for aspirin.

Other bleeding events that were reported more frequently in the Plavix group were epistaxis and hematoma.

Other Adverse Events

In CURE and CHARISMA, which compared Plavix plus aspirin to aspirin alone, there was no difference in the rate of adverse events (other than bleeding) between Plavix and placebo.

In CAPRIE, which compared Plavix to aspirin, pruritus was more frequently reported in those taking Plavix. 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 post-approval use of Plavix. 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.

• Blood and lymphatic system disorders: Agranulocytosis, aplastic anemia/pancytopenia, thrombotic thrombocytopenic purpura (TTP)
• Eye disorders: Eye (conjunctival, ocular, retinal) bleeding
• Gastrointestinal disorders: Gastrointestinal and retroperitoneal hemorrhage with fatal outcome, colitis (including ulcerative or lymphocytic colitis), pancreatitis, stomatitis, gastric/duodenal ulcer, diarrhea
• General disorders and administration site condition: Fever, hemorrhage of operative wound
• Hepato-biliary disorders: Acute liver failure, hepatitis (non-infectious), abnormal liver function test
• Immune system disorders: Hypersensitivity reactions, anaphylactoid reactions, serum sickness
• Musculoskeletal, connective tissue and bone disorders: Musculoskeletal bleeding, myalgia, arthralgia, arthritis
• Nervous system disorders: Taste disorders, fatal intracranial bleeding, headache
• Psychiatric disorders: Confusion, hallucinations
• Respiratory, thoracic and mediastinal disorders: Bronchospasm, interstitial pneumonitis, respiratory tract bleeding
• Renal and urinary disorders: Increased creatinine levels
• Skin and subcutaneous tissue disorders: Maculopapular or erythematous rash, urticaria, bullous dermatitis, eczema, toxic epidermal necrolysis, Stevens-Johnson syndrome, angioedema, erythema multiforme, skin bleeding, lichen planus, generalized pruritus
• Vascular disorders: Vasculitis, hypotension

7.1 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) and Dosage and Administration (2.4)].

Proton Pump Inhibitors (PPI)

A study was conducted with Plavix (300 mg loading dose followed by 75 mg/day) administered with a high dose (80 mg/day) of omeprazole. As shown in Table 3 below, with concomitant dosing of omeprazole, exposure (Cmax and AUC) to the clopidogrel active metabolite and platelet inhibition were substantially reduced. Similar reductions in exposure to the clopidogrel active metabolite and platelet inhibition were observed when Plavix and omeprazole were administered 12 hours apart (data not shown).

There are no adequate studies of a lower dose of omeprazole or a higher dose of Plavix in comparison with the approved dose of Plavix.

A study was conducted using Plavix (300 mg loading dose followed by 75 mg/day) and a high dose (80 mg/day) of pantoprazole, a PPI with less CYP2C19 inhibitory activity than omeprazole. The plasma concentrations of the clopidogrel active metabolite and the degree of platelet inhibition were less than observed with Plavix alone but were greater than observed when omeprazole 80 mg was co-administered with 300 mg loading dose followed by 75 mg/day of Plavix (Table 3).

Table 3. Comparison of Clopidogrel Active Metabolite Exposure and Platelet Inhibition with and without Proton Pump Inhibitors, Omeprazole and Pantoprazole

	% Change from Plavix (300 mg/75 mg) alone
Plavix plus	Cmax (ng/mL)		AUC		Platelet Inhibition* (%)
	Day 1	Day 5
Tags： 责任编辑：admin
【大 中 小】【打印】 【繁体】【投稿】【收藏】 【推荐】【举报】【评论】 【关闭】 【返回顶部】
分享到:
上一篇：OPSUMIT (macitentan) tablet, 治..	下一篇：PLAVIX(clopidogrel bisulfate) t..