Tevix®
Clopidogrel
Category:
Antithrombotic; platelet aggregation inhibitor.
(USP DI)
Chemistry:
Methyl (S) - 2 – chlorophenyl (4,5,6,7 - tetrahydrothieno [3,2-C] pyridin - 5 - yl) acetate bisulphate.
(Martindale)
C16H16CLNO2S ,H2SO4 = 419.9
Mechanism of action:
Clopidogrel inhibits adenosine diphosphate (ADP) binding to its platelet receptor and subsequent ADP - mediated activation of the glycoprotein GPIIb/IIIa complex, thus inhibiting platelet aggregation.
(USP DI, Facts)
Pharmacokinetics:
Absorption At least 50%
Protein binding for clopidogrel 98%
Protein binding for main circulating metabolite of clopidogrel 94%
Bioavailability Unaffected by food
Biotransformation Hepatic
Half-Life Elimination of carboxylic acid derivative: 8 hrs.
Onset of action After a single oral dose: 2 hrs.
After repeated doses of 75 mg: on the first day
Time to Peak Concentration Plasma: Approximately 1 hour for carboxylic acid derivative
Peak plasma concentration Approximately 3 mg per liter (carboxylic acid derivative) after repeated doses of 75 mg
Time to peak effect Steady - state inhibition of platelet aggregation with repeated doses of 75 mg/day: occurs between day 3 & 7
Duration of action Platelet aggregation & bleeding time gradually return to baseline levels within about 5 days after treatment is withdrawn
Elimination Renal: approximately 50%, 5 days after dosing
Fecal: approximately 46%, 5 days after dosing
(USP DI, Facts)
Indications:
Prophylaxis of myocardial infarction, stroke (thrombolitic), vascular death, peripheral artrial disease. Management of accute coronary syndrom.
(USPDI, PDR, Martindale)
Contraindications:
Hypersensivity to the drug or any component of the product; active pathological bleeding such as peptic ulcer or intracranial hemorrhage.
(Facts)
Warnings & Precautions:
- Thrombatic thrombocytopenic purpura (TTP): TTP has been reported rarely following use
of clopidogrel, sometimes after a short exposure (< 2 weeks).
- Clopidogrel prolongs the bleeding time and therefore should be used with caution in patient
who may be at risk of increased bleeding from trauma, surgery or other pathological conditions.
This Drug should be discontinued 5 days prior to surgery.
- The combination of aspirin and clopidogrel has not been shown to be more effective than clopidogrel alone, but the combination has been shown to increase major bleeding.
- Drugs that might induce such lesions should be used with caution in patients taking clopidogrel.
- Clopidogrel should be used with caution in hepatically - impaired and renally - impaired patients.
(PDR)
Pregnancy:
Category B - Clopidogrel should be used during pregnancy only if clearly needed.
(PDR)
Breast-feeding:
Should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the nursing woman.
(PDR)
Drug Interactions
Drug Interactions:
- Clopidogrel should be used with caution in patients receiving other drugs that increase the risk of bleeding including anticoagulants, other antiplatelets sush as aspirin, heparin, warfarin, ... and NSAIDs.
- Clopidogrel may inhibit the cytochrome P450 (2cq) at high concentrations invitro and interactions with drugs metabolised by this isoenzyme such as phenytoin, tamoxifen, tolbutamide, torsemide, fluvastatin and many NSAIDs; it may also inhibit CYP2B6 that
reduced the conversion of bupropion to its active metabolite.
- No clinically significant pharmacodynamic interactions were observed when clopidogrel was administered with atenolol,
nifedipine, phenobarbital, cimetidine or estrogen.
- The pharmacokinetics of digoxin or theophylline were not modified by the coadministration of clopidogrel.
- Developed rhabdomyolysis about 1 to 3 weeks after clopidogrel was added to their treatment in patients receiving ciclosporin with a statin.
(USPDI, PDR, Martindale)
Adverse Reactions:
Chest pain; accidental inflicted injury; influenza-like syndroms; pain; fatigue; edema; hypertension; headache; dizziness; abdominal pain; dyspepsia; diarrhea; nausea; hypercholesterolemia; arthralgia; back pain; purpura / bruise; epistaxis; depression; upper resp tract infection; dyspnea; rhinitis; bronchitis; coughing; rash; pruritus; urinary tract infection; syncope; palpitation; asthenia; fever; hernia; cardiac failure; coamps legs; hypoaesthesia; neuralgia; vertigo; constipation; vomiting; fibrillation atrial; hepatic enzymes increased; gout; hyperuricemia; non-protein nitrogen (NPN) increased; arthritis; arthrosis; GI hemorrhage; hematoma; platelets decreased; anxiety; insomnia; anemia; pneumonia; sinusitis; eczema; skin ulceration; cystitis; cataract; conjunctivitis; allergic reaction; necrosis ischemic; bilirubinemia; hepatitis infectious liver fatty; hemarthrosis; hematuria; hemoptysis; hemorrhage intracranial; homorrhage retroperitoneal; hemorrhage of operative wound; ocular hemorrhage; pulmonary hemorrhage; thrombocytopenia; anemia aplastic; anemia hypochromic; menorrhagia; hemothorax; bullous eruption; rash erythermatous; rash maculopapular; urticaria; abnormal renal functiion; acute renal failure; agranulocytosis; granulocytopenia; leukemia; leukopenia; neutrophils decreased; serum sickness; interstitial pneumonitis, stevens-johnson syndrome; lichen planus, myalgia.
(Facts, PDR, Martindale)
Over dosage:
Overdosage following clopidogrel administration may lead to prolonged bleeding time and subsequent bleeding complications.
(PDR)
Dosage & Administration:
Usual adult and geriatric dose
Antithrombotic-oral, 75mg (base) once a day.
Usual pediatric dose
Safety and efficacy have not been established.
(USP DI)
Storage:
Store below 30 and away from heat, moisture & direct light.
(USP DI)
How supplied:
Clopidogrel is available as 75mg, biconvex, pink and film-coated tablets. There are blisters of 3 × 10's in a box of 30's .