Generic Name: Warfarin Sodium
Brand Name:
ABTICOGAN (Donvalley)
COAGURIN (Atco)
FREEWARIN (Rakaposhi)
HEMOLYTE (Valor/Al-Hameed)
THROMBIN (KPL)
WARFARIN (Delta)
WARFIN (Shaigan)
WIRWIN (Winilton)
Chemical Class:
Coumarin Derivative
Therapeutic Class:
Anticoagulant
Indications and Dose:
- Prophylaxis of embolization in rheumatic heart disease and arterial fibrillation
- Prophylaxis after insertion of prosthetic heart valve
- Prophylaxis and treatment of venous thrombosis and pulmonary embolism
- Transient ischaemic attacks
Dose:
Adult: Initially 5-10 mg, to be taken on day 1, subsequent
doses dependent on prothrombin time reported as INR ( international
normalized ratio, ) a lower induction dose can be given over 3-4 weeks in
patients who do not require rapid anticoagulant, elderly patients to be given a
lower induction dose, maintenance 3-9 mg daily, to be taken at the same time
each day
Contraindications:
Active bleeding,
hemorrhagic blood dyscrasias, diathesis, recent cerebral, hemorrhage,
active ulceration of the GI tract, ulcerative colitis, open traumatic or
surgical wounds, recent or contemplated brain, eye, spinal cord surgery, or
prostatectomy, regional or lumbar block anesthesia, bacterial endocarditis,
pericarditis, visceral carcinoma, severe or malignant , hypertension,
eclampsia or preeclampsia, threatened abortion, emaciation, prey, history of
earfar in induced skin, necrosis, uncooperative, patient,
Precautions:
Trauma, infection, renal insufficiency, hypertension,
vasculitis, indwelling catheters, severe diabetes, active tuberculosis,
postpartum, protein C deficiency,
hepatic insufficiency, elderly, children, hyperthyroidism, hypothyroidism,
CHF, Polyarteritis, diverticulitis, antibiotic therapy, malnutrition
Pregnancy:
Use in 1st-trimester carriers significant risk to
the fetus, exposure in the 6th-9th week of gestation may
produce a pattern of defects termed the fetal warfarin syndrome with an
incidence up to 25% in some series, compatible with breastfeeding for normal
, full-term infants
Side effects/Adverse rections:
GI: Anorexia, cholestatic jaundice, hepatotoxicity mouth,
ulcers, nausea, paralytic ileus, sore mouth, vomiting
GU: Albuminuria , anuria, red-orange urine, renal tubular
necrosis
HEME: Hemorrhage, leukopenia
SKIN: Alopecia, dermatitis, exfoliative dermatitis,
necrosis or gangrene of skin and other tissues, urticaria
MISC: Systemic cholesterol microembolization (purple toe, syndrome)
Interactions:
Drugs
Acetaminophen: Repeated doses of acetaminophen may increase the hypoprothrombinemia response to warfarin
Allopurinol, amiodarone, ciprofloxacin, clarithromycin, erythromycin, fluconazole, fluorouracil, fluvastatin, fluvoxamine, lovastatin, glycogen, insoniazid, itraconazole ketoconazole, miconazole, nalidixic, ofloxacin, propafenone, propoxyphene, quinidine, sertraline, sulfonamides, sulfonylureas, thyroid hormones, triclofos, troleandomycin, vitamin E, zafirlukast: Enhanced hypothrombinemic response to warfarin
Aminoglutethimide, carbamazepine, cyclophosphamide, ethchlorvynol, griseofulvin, mercaptopurine, methimazole, mitotane, nafcillin, propylthiouracil, vitamin K, Reduced hypoprothrombinemia response to warfarin.
Aspirin: Increased risk of bleeding complications, Azathioprine, chloramphenicol, cimetidine, clofibrate, co-trimoxazole , danazol, dextrothyroxine, disulfiram, gemfibrozil, metronidazole, sulfinpyrazone, testosterone, derivatives: Enhanced hypoprothrombinemia response to warfarin.
Barbiturates, glutethimide, rifampin: reduced hypoprothrombinemia response warfarin.
Bile-acid binding resins: Variable effect on hypoprothrombinemia response to warfarin
Cephalosporins: Enhanced hypoprothrombinemia response to warfarin with moxalaotam, cefoperazone, cefunadole, cefotetan, and cefernetazole
Chloral hydrate: Transient increase in hypoprothrombinemia response to warfarin.
Ethanol: Enhanced hypoprothrombinemia response to warfarin with acute ethanol intoxication
Heparin: Prolonged activated partial thromboplastin time in patients receiving heparin, prolonged prothrombin times in patients receiving warfarin
Mesalamine: Warfarin effect inhibited in one case report
NSAIDs: Increased risk of bleeding in anticoagulated patients
Oral contraceptives: Increase or decrease in anticoagulant response, increased risk of thromboembolic disorders
Phenytoin: Transient increase in hypothrombinemic , response followed within 1-2 week by inhibition of hypoprothrombinemia response to warfarin
Salicylates: Increased risk of bleeding in anticoagulated patients ,enhanced hypoprothrombinemia response to warfarin with large salicylate doses.
