Drugs Information Online
Drugs and diseases reference index

Drugs and diseases reference index

Drugs A-Z List

Diseases & Conditions A-Z List

Herbs & Supplements

Medical Dictionary

Full Article

Popular Drugs

Popular Diseases & Conditions

Drugs reference index «Clopidogrel»


Pronunciation: (kloe-PID-oh-grel)Class: Aggregation inhibitor

Trade Names:Plavix- Tablet 75 mg (as base)


Clopidogrel is a thienopyridine derivative, chemically related to ticlopidine, which inhibits platelet aggregation. It acts by irreversibly modifying the platelet adenosine diphosphate (ADP) receptor. Therefore, platelet aggregation is inhibited for both ADP-mediated and ADP-amplified (by other agonists) platelet activation. Consequently, platelets exposed to clopidogrel are affected for the remainder of their lifespan.



Rapidly absorbed. T max is about 1 h. C max is about 3 mg/L.


98% reversibly bound to plasma proteins; active metabolite is 94% reversibly bound to plasma proteins.


Extensively metabolized in the liver; undergoes rapid hydrolysis to carboxylic acid derivative (active).


50% excreted in urine; 46% excreted in feces. The t ½ of active metabolite is 8 h.


2 h.


3 to 7 days.


About 5 days.

Indications and Usage

Reduction of atherosclerotic events (eg, MI, stroke, vascular death) in patients with atherosclerosis documented by recent stroke, recent MI, or established peripheral arterial disease; treatment of acute coronary syndrome (unstable angina/non–Q-wave MI), including patients managed medically and those managed with percutaneous coronary intervention (with or without stent) or coronary artery bypass graft; treatment of acute coronary syndrome in patients with ST-segment elevation acute MI; as a loading dose regimen of clopidogrel with aspirin to prevent cardiac adverse reactions in patients undergoing coronary stent implantation.


Hypersensitivity to any component of the product; active pathological bleeding such as peptic ulcer or intracranial hemorrhage.

Dosage and Administration

Acute Coronary Syndrome (Unstable Angina/Non–Q-Wave MI)Adults

PO Start with a 300 mg loading dose, then continue at 75 mg once daily, initiating and continuing aspirin (75 to 325 mg/day) in combination with clopidogrel.

Recent MI, Recent Stroke, or Established Peripheral Arterial Disease

PO 75 mg once daily with or without food.

Acute Coronary Syndrome (ST-Segment Elevation Acute MI)Adults

PO 75 mg once daily in combination with aspirin, with or without thrombolytic agents. Treatment may be initiated with or without a loading dose.

General Advice

Administer prescribed dose daily without regard to meals. Administer with food if GI upset occurs.


Store at controlled room temperature (59° to 86°F).

Drug Interactions

Clopidogrel inhibits CYP-450 2C9. Accordingly, clopidogrel may interfere with the metabolism of phenytoin, tamoxifen, tolbutamide, warfarin (prolongs bleeding time), torsemide, fluvastatin, and many NSAIDs, but there are no data with which to predict the magnitude of these interactions. Use caution when administering clopidogrel with any of these drugs.


Plasma levels may be elevated by clopidogrel, increasing the risk of adverse reactions.

Macrolide and related antibiotics (eg, erythromycin, telithromycin)

May inhibit the antiplatelet effects of clopidogrel.


Risk of hemorrhage may be increased.

Rifamycins (eg, rifampin)

Antiplatelet effect of clopidogrel may be enhanced.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Edema, hypertension (4%); hypotension, vasculitis (postmarketing).


Headache (8%); dizziness (6%); depression (4%); confusion, hallucinations (postmarketing).


Rash (4%); pruritus (3%); angioedema, erythema multiforme, lichen planus, Stevens-Johnson syndrome, toxic epidermal necrolysis (postmarketing).


Conjunctival, ocular, and retinal bleeding (postmarketing).


Abdominal pain (6%); diarrhea, dyspepsia (5%); nausea (3%); colitis (including ulcerative or lymphocytic), pancreatitis, stomatitis, taste disorders (postmarketing).


UTI (3%); glomerulopathy, increased creatinine levels (postmarketing).


Purpura/bruise (5%); epistaxis (3%); agranulocytosis, aplastic anemia/pancytopenia, bleeding (including intracranial, GI, and retroperitoneal hemorrhage), thrombotic thrombocytopenic purpura (postmarketing).


Abnormal LFTs, acute liver failure, hepatitis (postmarketing).


Hypercholesterolemia (4%).


Arthralgia, back pain (6%); myalgia, vasculitis (postmarketing).


Upper respiratory tract infection (9%); dyspnea (5%); bronchitis, rhinitis (4%); coughing (3%); bronchospasm, interstitial pneumonitis (postmarketing).


Accidental injury, chest pain, influenza-like symptoms (8%); pain (6%); fatigue (3%); anaphylactoid reactions, hypersensitivity reactions, serum sickness (postmarketing).




Monitor patient for bleeding or unusual bruising, and report to health care provider if noted.


Category B .




Safety and efficacy not established.

Renal Function

Use with caution.

Hepatic Function

Use with caution in patients with severe hepatic disease who may have bleeding diathesis.

Bleeding risk

Use with caution in patients with increased bleeding from trauma, surgery, or other pathological conditions. If undergoing surgery and antiplatelet effect is not desired, discontinue clopidogrel 5 days prior.

GI bleeding

Clopidogrel prolongs bleeding time. Use with caution in patients who have lesions with a propensity to bleed (eg, ulcers). Cautiously use drugs that might increase such lesions (eg, aspirin, NSAIDs).

Thrombotic thrombocytopenic purpura

May occur, sometimes after short-term exposure (less than 2 wk).



Prolonged bleeding with subsequent bleeding complications.

Patient Information

  • Advise patient that each dose may be taken without regard to meals but to take with food if stomach upset occurs.
  • Advise patient that if a dose is missed, to skip that dose and take the next dose at the regularly scheduled time.
  • Instruct patient not to change the dose or stop taking unless advised by health care provider.
  • Inform patient that it may take longer than usual to stop bleeding while taking clopidogrel and to report bleeding or unusual bruising to health care provider without delay.
  • Advise patient to inform health care providers about use of this drug before undergoing surgical or dental procedures, and before any new drug is taken.

Copyright © 2009 Wolters Kluwer Health.

  • Clopidogrel MedFacts Consumer Leaflet (Wolters Kluwer)
  • Clopidogrel Prescribing Information (FDA)
  • clopidogrel Advanced Consumer (Micromedex) - Includes Dosage Information
  • Plavix Prescribing Information (FDA)
  • Plavix Consumer Overview
  • Plavix Detailed Consumer Information (PDR)

See Also...

Comment «Clopidogrel»