Orfarin

Warfarin Na

Treatment & prevention of DVT & pulmonary embolism. Prevention of thromboembolic complications (stroke or systemic embolism) after MI & in patient w/ atrial fibrillation, cardiac valvular disease or prosthetic heart valves.

Adult (normal wt & spontaneous INR under 1.2) 10 mg/day on 3 consecutive days. Patients w/ inherited protein C or S deficiency Initially 5 mg/day in 3 days. Elderly Initially 5 mg/day for 2 days. Childn Day 1 (if spontaneous INR 1-1.3): Initially 0.2 mg/kg/day.

May be taken with or without food.

Hypersensitivity. Bleeding tendency (von Willebrand disease, hemophilia, thrombocytopenia & platelet function disorders); severe hepatic insufficiency & cirrhosis; untreated or uncontrolled HTN; recent intracranial bleeding; condition predisposing to intracranial haemorrhage (eg, aneurysm), tendency to fall; surgery of CNS or the eye; conditions predisposing GI & urinary tract haemorrhage (eg, previous GI bleeding complications, diverticulosis or malignancies); infectious endocarditis, pericarditis or pericardial effusion; dementia, pyschoses, alcoholism. Pregnancy (wk 6-12).

Initiate heparin therapy if rapid antithrombotic effect is needed. Patients w/ warfarin resistance. Start heparin for 5-7 days along w/ warfarin therapy in patients w/ hereditary deficiency of protein C or S. Hyperthyroidism, fever & uncompensated heart failure may enhance warfarin effect. Moderate hepatic insufficiency, & renal insufficiency & nephrotic syndrome. Galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption. Elderly. Pregnancy & lactation.

Bleeding, nausea, vomiting & diarrhoea.

Reduced absorption or enterohepatic circulation w/ cholestyramine. Induced hepatic metabolism w/ antiepileptics or antituberculotics. Inhibited hepatic metabolism w/ amiodarone or metronidazole. Drugs affecting platelets & primary hemostasis (ASA, clopidogrel, ticlopidine, dipyridamole, NSAIDs). Predisposition to severe bleeding complications w/ penicillins in large dose. Potentiated effect w/ anabolic steroids, azapropazone, erythromycin & some cephalosporins; alcohol; quinine; cranberry juice; oral sulphonylurea antidiabetics. Reduced effect w/ vit K. Increase effect w/ ASA, allopurinol, amiodarone, amoxicillin, argatroban, azapropazone, azithromycin, bezafibrate, capecitabine, carboxyuridine, celecoxib, clarithromycin, chloral hydrate, cefamandole, cefalexin, cefmenoxime, cefmetazole, cefoperazone, cefuroxime, cimetidine, ciprofloxacin, clofibrate, codeine, cyclophosphamide, dextropropoxyphene, (dextro) thyroxine, digoxin, disulfiram, doxycycline, erythromycin, etoposide, fenofibrate, feprazone, fluconazole, fluorouracil, flutamide, fluvastatin, fluvoxamine, gatifloxacin, gemfibrozil, grepafloxacin, ifosfamide, indometacin, flu vaccine, interferon-α & β, INH, itraconazole, ketoconazole, latamoxef, leflunomide, lepirudin, levofloxacin, lovastatin, metolazone, MTX, metronidazole, miconazole (also oral gel), moxifloxacin, nalidixic acid, norfloxacin, ofloxacin, omeprazole, oxyphenbutazone, paracetamol, phenylbutazone, piroxicam, proguanil, propafenone, propranolol, quinine, quinidine, rofecoxib, roxithromycin, simvastatin, sulfafurazole, sulfamethizole, sulfamethoxazole-trimethoprim, sulfaphenazole, sulfinpyrazone, sulfofenur, sulindac, (anabolic & androgenic) steroid hormones, tamoxifen, tegafur, tetracycline, tolmetin, tramadol, trastuzumab, troglitazone, valproic acid, vit A, vit E, zafirlukast. Decreased effect w/ azathioprine (barbiturates), carbamazepine, chlordiazepoxide, chlortalidone, cloxacillin, ciclosporin, dicloxacillin, disopyramide, griseofulvin, mercaptopurine, mesalazine, mitotane, nafcillin, nevirapine, phenobarb, primidone, rifampicin, spironolactone, trazodone, vit C. Potentiated effect w/ ginkgo (Ginkgo biloba), garlic (Allium sativum), dong quai (Angelica sinensis, contains coumarins), papaya (Carica papaya) or danshen (Salvia miltiorrhiza, decreases the warfarin elimination), or reduce it eg, ginseng (Panax spp) & St. John's wort (Hypericum perforatum).

Anticoagulants, Antiplatelets & Fibrinolytics (Thrombolytics)

B01AA03 - warfarin ; Belongs to the class of vitamin K antagonists. Used in the treatment of thrombosis.

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