아미오다론

제3형 항부정맥제

아미오다론은 주로 중증의 난치성 심실 및 상심실성 부정맥에 사용되는 강력하고 광범위한 **제3형 항부정맥제**입니다. 복잡한 약동학적 특성과 심각한 독성 가능성 때문에, 일반적으로 기존의 독성이 적은 치료법이 실패한 경우에만 제한적으로 사용됩니다. **임상 요점:** * 구조적으로 아미오다론은 요오드화 벤조푸란 유도체입니다. 200mg 정제 하나에는 약 75mg의 요오드가 포함되어 있어 갑상선 기능에 영향을 줄 수 있습니다. * 지용성이 매우 높아 조직에 광범위하게 분포하고 지방 조직에 축적되며, 이는 반감기가 매우 길고 변동성이 큰 원인이 됩니다. * 수의학에서는 특히 잠재성 확장성 심근병증(DCM)이 있으면서 빠른 넓은 QRS군 심실 빈맥이나 실신을 보이는 도베르만 핀셔에게 가장 흔히 사용됩니다. * 부작용(간독성 및 갑상선 기능 장애 포함)의 위험이 높으므로 철저한 모니터링이 필수적입니다.

작용 기전: Amiodarone is uniquely versatile, possessing properties of all four Vaughan-Williams antiarrhythmic classes, though it is primarily classified as a **Class III** agent. * **Class III (Primary):** Blocks **potassium (K+) channels** → prolongs phase 3 repolarization, action-potential duration (APD), and the effective refractory period (ERP) in myocardial cells. * **Class I:** Blocks **fast sodium (Na+) channels** → slows conduction velocity. * **Class II:** Non-competitively blocks **beta-adrenergic receptors** → provides sympatholytic effects, reducing heart rate. * **Class IV:** Weakly blocks **calcium (Ca2+) channels** → slows AV node conduction and suppresses automaticity. It is metabolized in the liver to its active metabolite, **desethylamiodarone**, which also contributes significantly to its antiarrhythmic effects.

동물 종별 용량

Dogs

For atrial fibrillation or ventricular arrhythmias primarily in ambulatory patients · 8-10 mg/kg PO every 12 hours · PO · q12h · Use caution if patient has bradycardia, AV blocks, or thyroid disorders.
For ventricular arrhythmias secondary to occult cardiomyopathy in Doberman pinschers · 10 mg/kg PO twice daily for one week and then 8 mg/kg PO once daily. After 6 months reduce to 5 mg/kg PO once daily. · PO · q12h then q24h · Long-term · For severe V-Tach, mexiletine is added at 5-8 mg/kg three times daily for one week. Once efficacy confirmed, patient weaned off mexiletine.
For ventricular tachycardia when other first line drugs (Class I antiarrhythmics ± beta-blockers) are ineffective · 10 mg/kg PO q12h for one week and then 5 mg/kg PO q12h for maintenance. · PO · q12h · Long-term
For SVTs or Vtach · 10-20 mg/kg PO once daily (q24h) loading for 5-7 days; 5-10 mg/kg PO once daily thereafter. · PO · q24h · Long-term
Ventricular and supraventricular arrhythmias, atrial fibrillation, ventricular pre-excitation syndromes · Dose not specified in monograph · PO/IV · Not specified · Not specified · Use as an IV infusion for recent onset atrial fibrillation has variable efficacy for restoring sinus rhythm but a high frequency of severe adverse effects.

Horses

For conversion of atrial fibrillation or ventricular tachycardia · 5 mg/kg/hr for one hour, followed by 0.83 mg/kg/hr for 23 hours and then 1.9 mg/kg/hour for the following 30 hours. · IV · CRI · Up to 54 hours · Infusion was discontinued when conversion occurred or when any side effects were noted. Regimen should be further adapted based upon PK/PD studies.

용량은 면허 수의 전문가를 위한 임상 참고 자료입니다. 항상 최신 라벨과 개별 환자에 대해 확인하십시오.

투여 경로

POIV

금기

Hypersensitivity to amiodarone or iodine
Severe sinus-node dysfunction
Severe sinus bradycardia
2nd or 3rd degree AV block
Bradycardial syncope

이상반응

Vomiting
Anorexia
Hepatopathy (elevated liver enzymes, bilirubinemia)
Bradycardia
Neutropenia
Thrombocytopenia
Positive Coombs' test
Corneal deposits
Injection site pain (IV)
Facial pruritus and hyperemia (IV)
Hind limb weakness (horses)
Diarrhea (horses)

약물 상호작용

Warfarin (Anticoagulants) · Significantly increases serum levels and/or pharmacologic/toxic effects of the anticoagulant.
Digoxin · Significantly increases serum levels and/or toxic effects of digoxin. · major
Cyclosporine · Increases cyclosporine levels; may increase creatinine.
Lidocaine · Significantly increases serum levels and/or toxic effects of lidocaine. · moderate
Methotrexate · Significantly increases serum levels and/or toxic effects with prolonged amiodarone administration. · major
Phenytoin · Significantly increases serum levels and/or toxic effects of phenytoin.
Procainamide · Significantly increases serum levels and/or toxic effects of procainamide.
Quinidine · Significantly increases serum levels and/or toxic effects of quinidine.
Azole Antifungals (ketoconazole, itraconazole) · Additive effects on QTc interval; possible serious arrhythmias.
Cisapride · Additive effects on QTc interval; possible serious arrhythmias.
Disopyramide · Additive effects on QTc interval; possible serious arrhythmias.
Dolasetron · Additive effects on QTc interval; possible serious arrhythmias.

모니터링

ECG (for antiarrhythmic efficacy and proarrhythmic effects)
Gastrointestinal signs (anorexia, vomiting)
CBC (for neutropenia, thrombocytopenia)
Serial liver enzymes and bilirubin (baseline and routine monitoring)
Thyroid function tests
Blood pressure
Pulmonary radiographs (if clinical signs such as dyspnea or cough occur)

과용량

Clinical overdosage experience is limited. **Expected Signs:** * Hypotension * Bradycardia * Cardiogenic shock * AV block * Hepatotoxicity **Treatment:** * Therapy is primarily **supportive**. * Bradycardia may be managed with a pacemaker or beta-1 agonists (e.g., isoproterenol). * Hypotension may be managed with positive inotropic agents or vasopressors. * *Note:* Neither amiodarone nor its active metabolite are dialyzable.

VetSheet 약물 레퍼런스는 면허 수의 전문가를 위한 임상 의사결정 보조 도구이며, 전문적 판단이나 제조사의 최신 라벨을 대신하지 않습니다.