메토헥시탈

초단기 작용 바르비투르산계 마취제

메토헥시탈은 초단기 작용 메틸화 산소바르비투르산계 마취제입니다. 현대 수의학에서는 대부분 프로포폴로 대체되었으나, 작용 종료가 지방으로의 재분포가 아닌 빠른 간 대사에 의존하기 때문에 **시각하운드**(예: 그레이하운드)에서 특히 유용합니다. 또한 위가 가득 찬 환자의 빠른 기관 삽관에도 유리하여 구토물 흡인을 방지할 수 있습니다. **임상 요점**: - 진통 및 근육 이완 효과가 없습니다. - 조직에 대한 자극성이 매우 강하며, 혈관 외로 유출될 경우 심각한 국소 조직 괴사를 일으킬 수 있습니다. - 티오펜탈보다 약 2배 강력하지만 작용 시간은 절반입니다.

작용 기전: Methohexital produces dose-dependent CNS depression by depressing the **reticular activating system** in the brainstem. - **Mechanism**: Binds to the **GABA_A receptor** complex → prolongs the opening of **chloride channels** → increases intracellular chloride influx → cellular hyperpolarization → profound inhibition of neuronal firing. - **Termination of Effect**: Unlike thiobarbiturates, methohexital is rapidly metabolized by the liver and does not depend on redistribution to fat to reverse its effects.

동물 종별 용량

Cats

Induction or sole anesthetic in non-premedicated cats · 11 mg/kg · IV · once · give approximately 1/2 the dose rapidly and then titrate to effect.
Induction or sole anesthetic in premedicated cats · 5.5-6.6 mg/kg · IV · once · 10-30% is given rapidly IV and then the remainder titrated to effect.

Dogs

Induction with premedication · 5 mg/kg · IV · once · give 1/2 to 3/4 of dose over 10 seconds. In 30 seconds if adequate plane is not reached to allow intubation, give additional drug. Delay will result in poor induction due to rapid redistribution.
Induction or sole anesthetic in non-premedicated dogs · 11 mg/kg · IV · once · give approximately 1/2 the dose rapidly and then titrate to effect.
Induction or sole anesthetic in premedicated dogs · 5.5-6.6 mg/kg · IV · once · 10-30% is given rapidly IV and then the remainder titrated to effect.

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

투여 경로

금기

Absence of suitable veins for IV administration
History of hypersensitivity reactions to barbiturates
Status asthmaticus
Cattle (due to unpredictable effects)

이상반응

Apnea
Hypotension
Muscle tremors
Seizures during recovery
Rough recoveries (especially in dogs)
Profound respiratory depression
Tissue necrosis (if extravasated)

약물 상호작용

CNS Depressants (e.g., alpha2-agonists, opioids) · Additive CNS and respiratory depression; premedication is usually preferred to reduce methohexital dosage required for inductions and to decrease rough recoveries.

모니터링

Plane of anesthesia
Respiratory rate and depth
Cardiac rate, rhythm, and blood pressure
CNS stimulation (seizures) upon recovery

과용량

**Narrow Safety Margin**: The lethal dose may only be 2-3 times the anesthetic dose. - **Clinical Signs**: Profound respiratory depression, apnea, hypotension, and cardiovascular collapse. - **Treatment**: Requires immediate mechanical ventilation and cardiovascular support. Postoperative seizures have been reported and can be treated with IV diazepam.

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