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와파린 나트륨

Warfarin Sodium

항응고제 - 쿠마린 유도체POIV개고양이말

다른 이름: Coumadin · Jantoven · Panwarfin · sodium warfarin · warfarinum natricum

VetSheet 수의사 팀 검수업데이트 2026년 4월 5일근거 기반 수의학 참고자료

0.22 mg/kgPO· q12h
— 🐕

용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.

동물 종별 용량

🌎 NA — North America🌍 EU — Europe

개

적응증용량경로빈도기간지역
Adjunctive maintenance therapy for venous thrombosis with or without pulmonary thromboembolism (PTE)0.22 mg/kgPOq12h—🌎 NA
Adjunctive therapy of thromboemboli0.22 mg/kgPOq12h—🌎 NA
Prophylactic use in patients with glomerular disease and severe proteinuria0.22 mg/kgPOonce daily—🌎 NA
  • Adjunctive maintenance therapy for venous thrombosis with or without pulmonary thromboembolism (PTE): Initially, then adjusted to achieve a PT prolongation of 1.25 to 1.5 times the pretreatment value.
  • Adjunctive therapy of thromboemboli: Target dosage to prolong PT by 1.25-1.5 times the pretreatment value.
  • Prophylactic use in patients with glomerular disease and severe proteinuria: Initially. Monitor PT and adjust dose so that PT is maintained at 1.5 times normal.

고양이

적응증용량경로빈도기간지역
Adjunctive maintenance therapy for venous thrombosis with or without pulmonary thromboembolism (PTE)0.5 mg (total dose per cat)POonce daily—🌎 NA
Maintenance therapy for feline arterial thromboembolism0.06 to 0.09 mg/kg/dayPOonce daily—🌎 NA
Long-term thromboprophylaxis0.06-0.09 mg/kg per dayPOonce daily—🌎 NA
Adjunctive therapy of thromboembolism0.25-0.5 mg (total dose) per catPOonce daily—🌎 NA
Cardiogenic arterial thromboembolism0.25-0.5 mg total dose per catPOq24h—🌎 NA
  • Adjunctive maintenance therapy for venous thrombosis with or without pulmonary thromboembolism (PTE): Initially, then adjusted to achieve a PT prolongation of 1.25 to 1.5 times the pretreatment value.
  • Maintenance therapy for feline arterial thromboembolism: Heparinization is recommended during the first 5 to 7 days that warfarin is administered.
  • Long-term thromboprophylaxis: Initially. Tablets should be crushed and mixed well due to unequal drug distribution. Overlap heparin and warfarin therapy by at least 4-5 days.
  • Adjunctive therapy of thromboembolism: Initially. Adjust dosage to prolong PT to twice normal value, or INR to be between 2-3. Overlap therapy with heparin.
  • Cardiogenic arterial thromboembolism: Heparin (150-250 Units/kg SC q8h) should be administered concurrently during the first 4-6 days. Target PT range is 1.3-1.6 times baseline, or INR 2.0-3.0.

말

적응증용량경로빈도기간지역
Adjunctive treatment of laminitis0.0198 mg/kgPOonce daily—🌎 NA
AnticoagulantInitially, 0.018 mg/kg PO once daily and increase dose by 20% every day until baseline PT is doubled. Final dose rates may be from 0.012 mg/kg to 0.57 mg/kg daily.POonce daily—🌎 NA
  • Adjunctive treatment of laminitis: Monitor OSPT (one-step prothrombin time) until prolonged 2-4 seconds beyond baseline.
  • Anticoagulant: ARCI UCGFS Class 5 Drug.

용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.

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개요

와파린은 쿠마린계 항응고제로, 주로 고양이, 개, 말의 혈전성 질환의 장기 치료 및 예방에 사용됩니다. 치료 지수가 좁고 치명적인 출혈 위험이 있으며 빈번하고 비용이 많이 드는 응고 모니터링이 필요하기 때문에 수의학에서의 사용은 다소 논란이 있으며, 다른 항응고제를 사용할 수 없는 특정 경우에 주로 사용됩니다.

작용 기전

Warfarin acts as an indirect anticoagulant by antagonizing Vitamin K.

  • It competitively inhibits the enzyme ​Vitamin K epoxide reductase (VKORC1)​.
  • This inhibition prevents the conversion of inactive Vitamin K epoxide back into its active form (Vitamin K hydroquinone).
  • Active Vitamin K is an essential cofactor for the γ-carboxylation (activation) of coagulation factors II, VII, IX, and X, as well as the endogenous anticoagulant proteins C and S.
  • ​Pathway:​ VKORC1 inhibition → Depletion of active Vitamin K → Production of inactive, undercarboxylated clotting factors (PIVKA) → Prolonged clotting times and anticoagulation.

안전성·주의사항

금기사항

  • Preexistent hemorrhagic tendencies or diseases
  • Patients undergoing or contemplating eye or CNS surgery
  • Major regional lumbar block anesthesia
  • Surgery of large, open surfaces
  • Active bleeding from the GI, respiratory, or GU tract
  • Aneurysm
  • Acute nephritis
  • Cerebrovascular hemorrhage
  • Blood dyscrasias
  • Uncontrolled or malignant hypertension
  • Hepatic insufficiency
  • Pericardial effusion
  • Pregnancy (Teratogenic - FDA Category X / Papich Class D)
  • Visceral carcinomas

부작용

  • Dose-related hemorrhage (primary adverse effect)
  • Anemia
  • Thrombocytopenia
  • Weakness
  • Hematomas and ecchymoses
  • Epistaxis (nosebleeds)
  • Hematemesis (vomiting blood)
  • Hematuria (blood in urine)
  • Melena (dark, tarry stools)
  • Hematochezia (fresh blood in stools)
  • Hemarthrosis (bleeding into joints)
  • Hemothorax
  • Intracranial hemorrhage
  • Pericardial hemorrhage
  • Death

주의

​Strict Monitoring Required:​ Warfarin has a narrow therapeutic index. Frequent monitoring of coagulation status (PT/INR) is mandatory to prevent fatal hemorrhage.

  • ​Teratogenicity:​ Warfarin is embryotoxic and causes congenital malformations. It is strictly contraindicated in pregnancy. Low-dose heparin is preferred if anticoagulation is required during pregnancy.
  • ​Nursing:​ Use with caution in nursing patients; prolonged prothrombin times have been reported in some breast-fed human infants.
  • ​Dietary Changes:​ Sudden changes in diet (especially foods high in Vitamin K) can alter the efficacy of warfarin.
  • ​Laboratory Interference:​ May cause falsely decreased theophylline values if using the Schack and Waxler ultraviolet method.

약물 상호작용

Acetaminophen, NSAIDs, Salicylates

May increase anticoagulant response (via protein displacement or platelet inhibition); increases bleeding risk.

Fluoroquinolones, Macrolides (Azithromycin, Erythromycin), Chloramphenicol, Sulfonamides, Co-trimoxazole

May increase anticoagulant response (often via inhibition of hepatic metabolism).

Cimetidine, Cisapride, Fluoxetine, Metronidazole, Sertraline

May increase anticoagulant response.

Amiodarone, Allopurinol, Danazol, Diazoxide, Ethacrynic acid, Pentoxifylline, Propylthiouracil, Quinidine, Zafirlukast

May increase anticoagulant response.

Anabolic Steroids, Thyroid Medications

May increase anticoagulant response.

Heparin

Increases anticoagulant response; often used concurrently during the initial overlap phase but requires careful monitoring.

Barbiturates (e.g., Phenobarbital), Rifampin, Griseofulvin

May decrease anticoagulant response (via induction of hepatic metabolizing enzymes).

Corticosteroids, Estrogens, Mercaptopurine, Spironolactone, Sucralfate

May decrease anticoagulant response.

Vitamin K

Directly antagonizes warfarin, decreasing its anticoagulant response (used as an antidote for overdose).

모니터링

  • Prothrombin Time (PT) - Target usually 1.25 to 1.5x (or up to 2x) normal depending on protocol
  • International Normalized Ratio (INR) - Target usually 2.0 to 3.0 (Note: not fully validated for veterinary patients)
  • PIVKA (Proteins Induced by Vitamin K Antagonists) - May be more sensitive than PT
  • Platelet counts and hematocrit (PCV)
  • Occult blood in stool and urine
  • Physical observations for bleeding (mucous membranes, bruising, epistaxis)
  • Clinical efficacy (resolution/prevention of thromboembolism)

약동학

반감기

고양이S-enantiomer: ~23-28 hours; R-enantiomer: ~11-18 hours

흡수

Rapidly and completely absorbed after oral administration in humans and cats.

분포

Highly bound to plasma proteins (approximately 99% in humans, >96% in cats). Wide species variation exists; horses have a higher free (unbound) fraction than rats, sheep, or swine. Only the free fraction is active. Does not enter milk in humans.

대사

Principally metabolized in the liver to inactive metabolites.

배설

Metabolites are excreted in urine and bile (then reabsorbed and excreted in the urine).

과다투여

Acute overdosages of warfarin may result in life-threatening hemorrhage.

  • ​Toxic Doses:​ In dogs and cats, single doses of 5-50 mg/kg have been associated with toxicity. Cumulative toxic doses are reported as 1-5 mg/kg for 5-15 days in dogs, and 1 mg/kg for 7 days in cats.
  • ​Lag Time:​ A lag time of 2-5 days may occur before clinical signs of toxicity manifest. Animals must be monitored closely during this period.
  • ​Treatment:​ If detected early, prevent absorption from the gut using standard decontamination protocols (emesis, activated charcoal). If clinical signs of bleeding are noted, treat with blood products (plasma/whole blood to replace active clotting factors) and ​Vitamin K1 (phytonadione)​.

제품

제형

  • Oral tablets
  • Powder for injection (lyophilized)

동물용의약품

  • None (ARCI Class 5 substance for racing)

인용의약품

  • Warfarin Sodium Oral Tablets (scored): 1 mg, 2 mg, 2.5 mg, 3 mg, 4 mg, 5 mg, 6 mg, 7.5 mg & 10 mg (Coumadin, Jantoven, generic)
  • Warfarin Sodium Powder for Injection, lyophilized: 5.4 mg (2 mg/mL when reconstituted) preservative-free in 5 mg vials (Coumadin)

규제 현황

규제 데이터 없음: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

보관·안정성

Tablets should be stored in tight, light-resistant containers at temperatures less than 40°C, preferably at room temperature. Powder for injection should be protected from light and used immediately after reconstituting.

보호자 정보

수의사의 지시에 따라 정확한 용량을 투여하는 것이 매우 중요합니다. 임의로 용량을 변경하지 마십시오. 출혈의 징후(창백한 잇몸, 비정상적인 멍, 코피, 혈뇨, 흑색변 또는 혈변, 갑작스러운 쇠약 등)가 보이면 즉시 수의사에게 연락하십시오. 외상으로 인한 심각한 출혈을 방지하기 위해 약을 복용 중인 반려동물(특히 고양이)은 실내에 머물게 하고 격렬한 활동을 피해야 합니다. 수의사의 동의 없이 새로운 약이나 영양제를 먹이지 마십시오.

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