메타돈
Methadone
Methadone hydrochloride
다른 이름: Dolophine · Methadose · Diskets · Comfortan · Synthadon · Amidine HCl · amidone HCl · methadoni hydrochloridum · Phenadone · Methadone hydrochloride · Metadona
VetSheet 수의사 팀 검수업데이트 2026년 4월 5일근거 기반 수의학 참고자료
감사 완료 v13 용량 근거
검토된 비계산 근거검토된 비계산 근거 (1)
근거 표시 전용 — 자동 계산 불가
Anesthesia premedication (extra-label)
Anesthesia premedication (extra-label): Methadone 0.1 – 0.6 mg/kg IV, IM, or SC 70,74
반드시 함께 고려할 임상 맥락 (2)
- NOTE: All listed dosages are based on the methadone HCl salt formulation (10 mg methadone HCl is equivalent to ≈8.9 mg of methadone). Most products are labeled with methadone HCl strength but check before administering to patients.
- Methadone injection should be stored at room temperature of 20°C to 25°C (68°F-77°F) and protected from light. Store vials in the manufacturer’s carton until ready for use.
용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.
개요
메타돈은 합성 강력 뮤-오피오이드 수용체 작용제(mu-opioid agonist)로, 주로 개와 고양이에서 마취 전 투약 및 진통제로 사용됩니다. 모르핀과 비교하여 정맥 주사 시 히스타민 방출이 현저히 적고, 구토나 과도한 진정을 덜 유발합니다.
임상 핵심 및 약리적 장점:
- 삼중 작용 기전: 대부분의 전통적인 오피오이드와 달리 메타돈은 뮤-작용제일 뿐만 아니라 비경쟁적 NMDA 수용체 길항제 및 모노아민(세로토닌 및 노르에피네프린) 재흡수 억제제로도 작용합니다.
- 신경병증성 통증: NMDA 길항 작용 덕분에 난치성 통증, 신경병증성 통증 치료 및 중추 감작(와인드업 통증) 예방에 특히 유용합니다.
- 생체이용률: 개에서 경구 생체이용률이 매우 낮아 수의학에서는 비경구 투여(IV, IM, SC)가 표준 경로입니다.
- 규제: 인체 남용 가능성이 높아 스케줄 II(C-II) 통제 약물로 분류됩니다.
작용 기전
Methadone provides analgesia through a unique, multi-modal mechanism of action:
- Mu-Opioid Receptor (MOR) Agonism: Binds to MORs in the central nervous system → inhibits adenylyl cyclase → decreases cAMP → promotes opening of inward-rectifying potassium channels and closing of voltage-gated calcium channels → hyperpolarization of neurons and decreased release of nociceptive neurotransmitters (e.g., Substance P, glutamate).
- NMDA Receptor Antagonism: Acts as a non-competitive antagonist at the N-methyl-D-aspartate (NMDA) receptor → blocks glutamate binding → reduces central sensitization and hyperalgesia.
- Monoamine Reuptake Inhibition: Inhibits the presynaptic reuptake of serotonin (5-HT) and norepinephrine (NE) → increases monoamine concentrations in the synaptic cleft → enhances descending inhibitory pain pathways in the spinal cord.
안전성·주의사항
금기사항
- Late-term pregnancy (due to risks of respiratory depression and stillbirths)
- Known hypersensitivity to methadone
- No specific contraindications available in the monograph, but use with caution in patients with severe respiratory compromise or hepatic impairment.
부작용
- Panting
- Whining or vocalization
- Defecation
- Constipation
- Bradycardia
- Pronounced CNS excitement (in horses at IV doses ≥ 0.1 mg/kg)
- Respiratory depression (primarily under general anaesthesia)
- Transient excitation (when given IV)
- Salivation (when given via oral transmucosal route in cats due to preservatives)
- Constriction of gastrointestinal sphincters (e.g., pyloric sphincter)
- Reduction in gastrointestinal motility (with prolonged use)
- Neonatal sedation (crosses the placenta)
주의
All opiates should be used with caution in patients with heart failure, hypertension, head injuries, elevated CSF pressures, and in geriatric or severely debilitated patients.
Note: Methadone can increase plasma amylase and lipase values up to 24 hours following administration due to increased biliary tract pressure.
약물 상호작용
May increase risks for arrhythmias
Potentiates sedative and analgesic effects; combination with medetomidine may cause severe hypoxemia in dogs breathing room air
May increase methadone levels in humans (does not appear to be true for dogs)
May increase risks for arrhythmias
May cause increased CNS or respiratory depression
May increase potential for electrolyte abnormalities
Opiates may decrease diuretic efficacy in CHF patients
May inhibit metabolism of methadone and increase levels in humans (does not appear to be true for dogs)
Potential for severe CNS/behavioral reactions; concomitant use should be avoided
Methadone may enhance neuromuscular blockade
May decrease methadone levels in humans (probably does not affect dogs)
May decrease methadone levels in humans (probably does not affect dogs)
May increase methadone levels
May decrease methadone levels in humans (probably does not affect dogs)
Methadone may exacerbate the effects of tricyclic antidepressants
Opiates may potentiate anticoagulant activity
Methadone may increase zidovudine levels
Increased CNS or respiratory depression
모니터링
- Analgesic or preanesthetic efficacy
- Respiratory rate and depth (monitor for respiratory depression, especially at higher doses)
- Heart rate (bradycardia)
- CNS depression or excitation
- Respiratory rate and depth (especially under general anaesthesia)
- Pain scores (due to individual variation in response)
- Level of sedation
- Gastrointestinal motility (with prolonged use)
약동학
반감기
흡수
In dogs, methadone has poor oral bioavailability (not significantly affected by ketoconazole or omeprazole). Subcutaneous bioavailability is ~80% with peak levels around 1 hour. In horses, orally administered methadone is well absorbed but rapidly eliminated.
분포
Highly lipid-soluble and widely distributed. In humans, it is extensively bound to plasma proteins (60-90%).
대사
Hepatic. Unlike in humans, CYP3A does not appear to be a major metabolic pathway for methadone biotransformation in dogs. Metabolites are inactive.
배설
In dogs, clearance is about 25-30 mL/kg/min.
과다투여
Overdosage may produce profound respiratory and/or CNS depression in most species. Newborns are particularly susceptible. Other toxic effects include cardiovascular collapse, hypothermia, and skeletal muscle hypotonia.
Treatment:
- Naloxone is the reversal agent of choice for treating respiratory depression. In massive overdoses, naloxone doses may need to be repeated because naloxone's effects might diminish before sub-toxic levels of methadone are attained.
- Mechanical respiratory support should be considered in severe cases.
- Dialysis, charcoal hemoperfusion, or forced diuresis do not appear to be beneficial.
제품
제형
- Injection
- Oral tablets
- Dispersible tablets
- Oral solution/liquid concentrate
- Injectable: 10 mg/ml solution (including generic preservative-free preparations)
- Oral: 10 mg tablets
동물용의약품
- Comfortan 10 mg/ml solution for injection
- Synthadon 10 mg/ml solution for injection
인용의약품
- Methadone HCl Injection: 10 mg/mL
- Methadone HCl Oral Tablets: 5 mg & 10 mg
- Methadone HCl Dispersible Tablets: 40 mg
- Methadone HCl Oral Solution/Liquid Concentrate: 1 mg/mL, 2 mg/mL & 10 mg/mL
- Generic methadone 10 mg tablets
규제 현황
Authorized veterinary preparations available.
Subject to strict safe custody and register requirements.
규제 데이터 없음: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
보관·안정성
Store at room temperature and protect from light. Methadone injection is reportedly stable when mixed in a syringe with acepromazine, but is NOT compatible with pentobarbital, phenobarbital, amobarbital, or thiopental.
보호자 정보
메타돈은 강력하고 엄격하게 관리되는 오피오이드 진통제입니다. 주사로 투여할 경우 일반적으로 동물병원 내에서 수의사의 직접적인 감독 하에 이루어집니다.
가정에서 반려동물의 통증 관리를 위해 경구용 메타돈이 처방된 경우:
- 지시된 용량을 엄격히 준수하십시오. 수의사와 상의 없이 투여량을 늘리거나 줄이지 마십시오.
-
매우 위험: 이 약은 어린이와 다른 반려동물의 손이 절대 닿지 않는 안전한 곳에 보관해야 합니다. 사람(특히 어린이)이 잘못 복용할 경우 치명적인 호흡 억제를 유발할 수 있습니다.
- 가벼운 졸음, 헐떡임, 낑낑거림 또는 변비와 같은 부작용이 나타나는지 관찰하십시오.
- 즉시 수의사의 진료를 받으십시오: 반려동물이 극도로 무기력해지거나, 호흡 곤란을 겪거나, 호흡이 비정상적으로 느려지는 경우.
VetSheet 의약품 참고자료는 수의사 전문가의 임상 의사결정 지원을 위한 것이며, 전문적 판단이나 제조사의 최신 약물 정보를 대체할 수 없습니다.