ゾラゼパムおよびチレタミン
**ゾラゼパム/チレタミン**（一般的にZoletilまたはTelazolとして知られる）は、犬および猫の全身麻酔に獣医療で広く使用される配合注射用麻酔薬です。解離性麻酔薬（チレタミン）とベンゾジアゼピン（ゾラゼパム）を組み合わせることで、筋弛緩を伴う麻酔を提供します。 > **臨床上の警告：** この配合剤は、痛みを伴う手術の単独麻酔薬として使用すべきではありません。十分な内臓鎮痛作用を欠いているため、適切な鎮痛薬（オピオイド、NSAIDsなど）と併用する必要があります。 **臨床のポイント：** この薬剤からの覚醒は長引くことがあり（2〜6時間）、特に高用量を投与された犬では、荒れたり興奮したりすることがあります。前投薬（α2作動薬やフェノチアジン系など、相互作用に注意しつつ）を行うことで、覚醒がスムーズになることがよくあります。猫の覚醒は犬よりも長引く傾向があります。
作用機序: The drug is a 1:1 combination of two active principles with complementary mechanisms: * **Zolazepam:** A benzodiazepine that enhances the activity of **GABA** (gamma-aminobutyric acid) → the major inhibitory neurotransmitter within the CNS. This provides sedative, anxiolytic, and muscle-relaxing actions, counteracting the muscle rigidity typically caused by dissociative agents. * **Tiletamine:** A dissociative anesthetic (pharmacologically similar to ketamine) that antagonizes **NMDA (glutamic acid) receptors** → depresses certain cerebral regions (thalamus and cortex) while the limbic system remains active, generating a state of dissociative anesthesia.
動物種別の用量
- General anaesthesia · 5-10 mg/kg · IV · single dose · Duration of anaesthesia is 20-60 minutes · Dose refers to the combined tiletamine/zolazepam (100 mg/ml). Adjust depending on degree of pain expected and depth required.
- General anaesthesia · 7-25 mg/kg · IM · single dose · Duration of anaesthesia is 20-60 minutes · Dose refers to the combined tiletamine/zolazepam (100 mg/ml). Adjust depending on degree of pain expected and depth required.
- General anaesthesia · 5-7.5 mg/kg · IV · single dose · Duration of anaesthesia is 20-60 minutes · Dose refers to the combined tiletamine/zolazepam (100 mg/ml). Adjust depending on degree of pain expected and depth required.
- General anaesthesia · 10-15 mg/kg · IM · single dose · Duration of anaesthesia is 20-60 minutes · Dose refers to the combined tiletamine/zolazepam (100 mg/ml). Adjust depending on degree of pain expected and depth required.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Severe cardiac disease
- Severe respiratory disease
- Hypertensive disease
- Renal insufficiency
- Pancreatic insufficiency
- Hepatic insufficiency
- Head trauma or intracranial tumours
- Pregnancy (crosses the placenta and causes fatal respiratory depression in neonates)
有害事象
- Excessive salivation (ptyalism)
- Muscle rigidity during recovery
- Prolonged and excitable recovery (especially in dogs at higher doses)
- Pain on intramuscular injection (particularly in cats)
- Respiratory depression (can be fatal in neonates)
- Hypothermia
薬物相互作用
- Phenothiazines (e.g., Acepromazine) · Increased cardiorespiratory depression and increased hypothermic effect during the last phase of anesthesia. · major
- Chloramphenicol · Slows down the elimination of the anesthetics if used during the pre- or intraoperative period. · moderate
モニタリング
- Heart rate and rhythm
- Respiratory rate and depth
- Body temperature (monitor closely for hypothermia)
- Depth of anesthesia (jaw tone, palpebral reflex)
- Quality of recovery (monitor for excitation or rigidity)
過量投与
Overdosage increases the risk of severe **cardiorespiratory depression**, prolonged anesthesia, and highly excitable or rough recoveries. Treatment is supportive, including mechanical ventilation if respiratory failure occurs, thermal support for hypothermia, and potentially benzodiazepine antagonists (flumazenil) for the zolazepam component, though this leaves the tiletamine unopposed.
VetSheet の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。