臭化ベクロニウム
**臭化ベクロニウム**は、中時間作用型の合成アミノステロイド系**非脱分極性神経筋遮断薬**です。 主な臨床的特徴は以下の通りです： * **手術の補助**：主に全身麻酔の補助として使用され、深い骨格筋弛緩をもたらします。 * **処置の円滑化**：気管挿管、人工呼吸、および精密な外科手術（眼科や整形外科手術など）を容易にするのに最適です。 * **心血管系の安定性**：他の神経筋遮断薬とは異なり、心血管系への影響はごくわずかであり、通常ヒスタミン遊離を引き起こしません。 * **鳥類への使用**：鳥類の虹彩には横紋肌が含まれているため、散瞳（瞳孔散大）を誘発するために局所的に使用されたことがあります。 > **重要な臨床的真珠（パール）**：ベクロニウムには**鎮痛、鎮静、または健忘作用は一切ありません**。横隔膜を含むすべての骨格筋を麻痺させます。投与前および投与中は、患者が完全に麻酔され、意識がなく、陽圧人工呼吸を受けている必要があります。
作用機序: Vecuronium acts as a competitive antagonist at the **nicotinic cholinergic receptors (nAChRs)** located at the **motor endplate** of the neuromuscular junction. * **Mechanism**: Vecuronium binds to the alpha subunits of the nAChR → prevents **acetylcholine (ACh)** from binding → inhibits depolarization of the muscle fiber → results in **flaccid paralysis**. * **Potency**: It is highly potent, estimated to be equipotent to up to 3 times as potent as pancuronium on a weight basis, but with a shorter duration of action (approximately ⅓ to ½ as long).
動物種別の用量
- Muscle relaxation during anesthesia · 20-40 micrograms/kg (0.02-0.04 mg/kg) · IV
- Neuromuscular blockade (loading dose) · 0.1 mg/kg · IV · initially · Produces blockade for 25-30 min · Lower loading dose of 0.05 mg/kg IV produces shorter duration (16-19 min).
- Neuromuscular blockade (maintenance) · 0.03 mg/kg increments OR 0.1-0.2 mg/kg/h · IV · PRN or CRI · As needed during surgery · Repeated doses are relatively non-cumulative in healthy animals.
- Muscle relaxation during anesthesia · 0.1 mg/kg · IV · initially (after meperidine and/or acepromazine pre-op 30 minutes before); may give subsequent incremental doses of 0.04 mg/kg · Duration of action after initial dose averages 25 minutes.
- Muscle relaxation during anesthesia · 10-20 micrograms/kg · IV
- Muscle relaxation (CRI maintenance with propofol-fentanyl) · 0.2 mg/kg/hr · IV · CRI
- Muscle relaxation (CRI maintenance with fentanyl-isoflurane or fentanyl-sevoflurane) · 0.1 mg/kg/hr · IV · CRI
- Neuromuscular blockade (loading dose) · 0.1 mg/kg · IV · initially · Produces blockade for 25-30 min · Lower loading dose of 0.05 mg/kg IV produces shorter duration (16-19 min).
- Neuromuscular blockade (maintenance) · 0.03 mg/kg increments OR 0.1-0.2 mg/kg/h · IV · PRN or CRI · As needed during surgery · Repeated doses are relatively non-cumulative in healthy animals.
投与経路
禁忌
- Known hypersensitivity to vecuronium or bromides
- Conscious or inadequately anesthetized animals
- Lack of facilities for positive pressure ventilation/mechanical ventilation
- Severe hepatic dysfunction (relative contraindication; atracurium preferred)
有害事象
- Profound, prolonged musculoskeletal paralysis (pharmacologic effect)
- Skeletal muscle weakness
- Respiratory arrest (if mechanical ventilation is not provided)
- Prolonged apnea (expected pharmacological effect)
- No cardiovascular effects or histamine release reported at clinical doses
薬物相互作用
- Other Non-Depolarizing Muscle Relaxants · May have a synergistic effect if used concurrently with vecuronium.
- Succinylcholine · May speed the onset of action and enhance the neuromuscular blocking actions of vecuronium; do not give vecuronium until succinylcholine effects have subsided.
- Aminoglycosides · May enhance or prolong the neuromuscular blocking activity. · major
- Inhalant Anesthetics (Halothane, Isoflurane, Sevoflurane) · May enhance or prolong the neuromuscular blocking activity.
- Clindamycin, Lincomycin · May enhance or prolong the neuromuscular blocking activity.
- Dantrolene · May enhance or prolong the neuromuscular blocking activity.
- Magnesium Salts · May enhance or prolong the neuromuscular blocking activity.
- Piperacillin, Mezlocillin · May enhance or prolong the neuromuscular blocking activity.
- Quinidine · May enhance or prolong the neuromuscular blocking activity.
- Tetracyclines · May enhance or prolong the neuromuscular blocking activity.
- Verapamil · May enhance or prolong the neuromuscular blocking activity.
- Volatile anaesthetics · Prolonged neuromuscular blockade · major
モニタリング
- Level of neuromuscular relaxation (using a peripheral nerve stimulator/train-of-four monitor)
- Heart rate, blood pressure, and ECG
- SpO2 and End-tidal CO2 (capnography)
- Core body temperature
- Neuromuscular function (Peripheral nerve stimulator / Train-of-Four)
- Continuous respiratory monitoring (Capnography/ETCO2, SpO2)
- Heart rate and blood pressure
- Acid-base and electrolyte status (especially potassium)
過量投与
No cases of vecuronium overdosage have been reported in human or veterinary medicine. **Treatment of Overdose**: * Treat conservatively with **mechanical ventilation**, oxygen therapy, and IV fluids until the block wears off naturally. * **Pharmacologic Reversal**: Blockade can be reversed using an **anticholinesterase agent** (e.g., edrophonium, physostigmine, or neostigmine) combined with an **anticholinergic** (atropine or glycopyrrolate) to prevent severe bradycardia and excessive salivation. * *Suggested Reversal Protocol*: Neostigmine **0.06 mg/kg IV** administered after Atropine **0.02 mg/kg IV**.
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。