ロクロニウム臭化物
ロクロニウム臭化物は、アミノステロイド系の競合的・**非脱分極性神経筋遮断薬（NMBA）**です。主に全身麻酔の補助薬として使用され、迅速な気管挿管を容易にし、繊細な外科手術（眼科、神経、胸部外科など）中に深い骨格筋弛緩を提供します。 主な薬理学的特徴は以下の通りです： * **迅速〜中等度の発現**：ベクロニウムやアトラクリウムと比較して作用発現が早く（ベクロニウムの2〜3倍）、サクシニルコリンとほぼ同等の速さですが、副作用は少なくなっています。 * **中等度の作用時間**：ベクロニウムやアトラクリウムと同様の作用時間です。 * **心血管系の安定性**：古いNMBAと比較して、心血管系への影響やヒスタミン放出作用が最小限に抑えられています。 > **臨床上の重要ポイント：** ロクロニウムのような神経筋遮断薬には、**鎮痛、鎮静、健忘作用は全くありません**。意識がある、または麻酔が不十分な患者に投与すると、完全に意識があり痛みを感じる状態で全身麻痺に陥るという恐ろしい体験を引き起こします。必ず深く麻酔され、人工呼吸器がすぐに利用できる患者にのみ使用しなければなりません。
作用機序: Rocuronium acts by competitively antagonizing acetylcholine (ACh) at the neuromuscular junction. * **Mechanism**: It binds to **nicotinic cholinergic receptors** at the motor end plate of skeletal muscle. * **Pathway**: Rocuronium occupies the receptor site → prevents ACh from binding → inhibits depolarization of the muscle cell membrane → results in flaccid paralysis. * **Reversal**: Because the blockade is competitive, it can be antagonized by increasing the concentration of ACh in the synaptic cleft. This is achieved using **acetylcholinesterase inhibitors** (e.g., neostigmine, edrophonium). Alternatively, rocuronium can be directly encapsulated and inactivated in the plasma by the selective relaxant binding agent **sugammadex**.
動物種別の用量
- As a neuromuscular blocker · 0.6 mg/kg IV · IV · Single dose · Rapid onset, short duration of action, and does not cause significant changes in heart rate.
- Neuromuscular blockade / Endotracheal intubation · 0.3-0.6 mg/kg i.v. · IV · Single dose · Approx 20 min at 0.6 mg/kg · 0.6 mg/kg has a rapid onset and short duration of action (20 min). Requires prompt successful intubation and ventilation.
- As a neuromuscular blocker · 0.6 mg/kg IV · IV · Single dose · Provided predictable blockade without hemodynamic changes, but large variation between individuals; monitoring of neuromuscular block is essential.
- As a neuromuscular blocker · 0.5 mg/kg bolus and then a CRI was started immediately at 0.2 mg/kg/hour · IV · Bolus followed by CRI · Authors concluded it was effective and easily applicable, but further work is required on infusion titration.
- Neuromuscular blockade during anaesthesia · 0.4 mg/kg i.v. followed, when required, by a maintenance dose of 0.16 mg/kg i.v. prn or continuous rate infusion of 0.2 mg/kg/h · IV · prn or CRI · As needed during surgery · Monitoring with a nerve stimulator is recommended.
- Centralize the globe for ophthalmic surgery · 0.05-0.1 mg/kg i.v. · IV · Single dose or prn · As needed · Considerably lower doses are required for this indication.
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
- Hypersensitivity to rocuronium or other neuromuscular blocking agents
- Patients who are not adequately anesthetized or sedated
- Settings lacking immediate access to intubation, mechanical ventilation, and oxygen therapy
- Conscious or inadequately anaesthetized animals
- Lack of positive pressure ventilation facilities
有害事象
- Changes in heart rate (mild, transient tachycardia)
- Changes in blood pressure (hypotension or hypertension)
- Severe anaphylaxis (reported in humans)
- Histaminoid reactions (rare)
- Severe burning pain at the injection site (if administered before deep anesthesia is achieved)
- Increased heart rate
- Mild hypertension (at high doses)
薬物相互作用
- Other Non-depolarizing Muscle Relaxants · May have a synergistic effect if used concurrently with rocuronium.
- Succinylcholine · May speed the onset of action and enhance the neuromuscular blocking actions of rocuronium; do not give rocuronium until succinylcholine effects have subsided.
- Aminoglycosides (e.g., gentamicin, amikacin) · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Inhalant Anesthetics (halothane, isoflurane, sevoflurane) · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Clindamycin, Lincomycin · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Dantrolene · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Magnesium Salts · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Piperacillin, Mezlocillin · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Quinidine · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Tetracyclines · May enhance or prolong the neuromuscular blocking activity of rocuronium.
- Verapamil · May enhance or prolong the neuromuscular blocking activity of rocuronium.
モニタリング
- Degree of neuromuscular blockade (using a peripheral nerve stimulator/Train-of-Four monitor)
- Heart rate and rhythm
- Blood pressure
- Oxygenation (SpO2) and ventilation (End-tidal CO2)
- Depth of anesthesia
- Neuromuscular blockade depth (using a peripheral nerve stimulator)
- Heart rate and blood pressure
- Spontaneous respiratory effort during recovery
過量投与
Overdosage with neuromuscular blocking agents results in **prolonged neuromuscular blockade** (extended paralysis). * **Primary Treatment**: Maintenance of a patent airway, continuous mechanical ventilation, oxygenation, and adequate sedation/anesthesia until full recovery of muscle function is assured. * **Reversal**: Only after spontaneous evidence of recovery is observed should administration of an anticholinesterase drug (e.g., neostigmine) combined with an anticholinergic agent (e.g., atropine or glycopyrrolate to prevent severe bradycardia) be considered. * **Specific Antidote**: Rocuronium's effects can be rapidly and specifically reversed by **sugammadex**, a cyclodextrin binding agent that encapsulates the drug in the plasma.
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。