ケタミン
Ketamine
Ketamine Hydrochloride
別名: Ketaset · Ketaflo · Ketalar · Ketaject · VetaKet · Anaestamine · Anesketin · Ketavet · Narketan-10 · Vetalar-V · CI-581 · CL-369 · CN-52372-2 · ketamini hydrochloridum · Ketamine hydrochloride
VetSheet 獣医チームが監修更新日 2026年4月5日エビデンスに基づく獣医学リファレンス
監査済み v13 用量エビデンス
構造化された用量計算エビデンスKetamine/benzodiazepine combinations — Postoperative analgesia
認証済み獣医師の確認が必要
NA
必ず考慮する臨床コンテキスト (4)
- 1. Ketamine is used in many different combinations with other agents. The following are representative, but not necessarily inclusive; it is suggested to refer to a recent veterinary anesthesia reference for more information. 31,32
- 2. Do not confuse IV CRI dosages listed as mg/kg/HOUR with those listed as µg/kg/MINUTE.
- a) Ketamine/benzodiazepine combinations:
- Ketamine injection should be stored between 15°C to 30°C (59°F-86°F) and protected from light. The discard dates after first vial puncture vary by manufacturer; refer to the specific product label for further information.
用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。
概要
ケタミンは、獣医学で広く使用されている即効性の解離性全身麻酔薬および鎮痛薬です。
- 薬物クラス：フェンサイクリジン（PCP）誘導体です。
- 臨床効果：深部の体性鎮痛、健忘、および視床皮質系と辺縁系の解離を特徴とするカタレプシー状態を誘発します。従来の麻酔薬とは異なり、第III期麻酔を誘発しません。
- 反射の維持：患者は通常、咽頭、喉頭、角膜、および足底反射を含む脳神経反射を維持します。目は開いたままになることがよくあります。
- 心血管系：交感神経の緊張が高まるため、一般的に心血管系を刺激し（心拍数、血圧、心拍出量を増加させる）、血行動態が不安定な患者に有用です（ただし、肥大型心筋症には禁忌です）。
臨床のポイント：ケタミン単独では筋肉の硬直を引き起こし、内臓鎮痛に欠けるため、スムーズな導入、適切な筋弛緩、およびよりスムーズな回復を確実にするために、筋弛緩薬（ミダゾラムやジアゼパムなどのベンゾジアゼピン系）またはα-2作動薬（デクスメデトミジン、キシラジンなど）とほぼ常に併用されます。
作用機序
Ketamine exerts its effects through multiple central nervous system pathways:
- NMDA Receptor Antagonism: Acts as a non-competitive antagonist at the N-methyl-D-aspartate (NMDA) receptor → binds to the PCP site inside the calcium channel pore → prevents glutamate-mediated calcium influx → blocks central sensitization and prevents the "wind-up" phenomenon associated with chronic or severe pain.
- Neurotransmitter Modulation: Inhibits GABA and blocks the reuptake of serotonin, norepinephrine, and dopamine in the CNS.
- CNS Dissociation: Depresses the thalamoneocortical system (responsible for sensory perception) while simultaneously activating the limbic system (involved in memory and emotion).
- Sympathetic Stimulation: Increases sympathetic tone by promoting norepinephrine release → leads to increased heart rate, cardiac output, and blood pressure. Note: Ketamine has direct negative inotropic effects on the myocardium, which are usually masked by this sympathetic surge unless the patient is catecholamine-depleted.
安全性・警告
禁忌
- Prior hypersensitivity reactions to ketamine
- Animals intended for human consumption
- Use as a sole agent for major surgery (due to poor muscle relaxation and visceral analgesia)
- Increased cerebrospinal fluid (CSF) pressure or head trauma
- Significant hypertension, heart failure, or arterial aneurysms
- Hypertrophic cardiomyopathy (HCM) in cats
- Increased intra-ocular pressure or open globe injuries (relative)
- Procedures involving the pharynx, larynx, or trachea (relative)
- Preexisting seizure disorders (use with extreme caution)
- Animals whose eyes are at risk of perforation
- Raised intraocular pressure (IOP)
- Raised intracranial pressure (ICP)
有害事象
- Hypertension
- Hypersalivation
- Respiratory depression (at high doses or rapid IV administration)
- Hyperthermia (especially in cats)
- Emesis
- Vocalization
- Erratic and prolonged recovery (emergence delirium)
- Dyspnea
- Spastic jerking movements and muscular tremors
- Seizures (up to 20% of cats at therapeutic doses)
- Hypertonicity and opisthotonos
- Cardiac arrest
- Pain after IM injection
- Eyes remain open (risk of corneal drying/ulceration)
- Cardiovascular depression and arrhythmias (in animals with high sympathetic tone, shock, or severe CV disease)
- Tachycardia (following high IV doses)
- Marked respiratory depression (in some animals)
- Skeletal muscle hypertonicity and spontaneous movement (if used alone)
- Spacey, abnormal behaviour or dysphoria during recovery (1-2 hours)
- Drug accumulation and prolonged recovery (with prolonged infusion)
注意事項
Cardiovascular Caution: Ketamine increases heart rate, blood pressure, and myocardial oxygen consumption. Avoid in patients where this is detrimental (e.g., unstable shock, congestive heart failure, hypertrophic cardiomyopathy).
Ocular Care: Cats' eyes remain open after receiving ketamine. Protect from injury and apply an ophthalmic lubricant (e.g., Lacri-Lube) to prevent excessive corneal drying.
- Hepatic/Renal Insufficiency: Use with caution. In cats, ketamine is excreted almost exclusively via the kidneys; reduce doses or use cautiously in feline renal disease.
- Sympathetic Tone: Use with caution in animals with preexisting increased sympathetic tone (e.g., pheochromocytoma, hyperthyroidism).
- Recovery: Minimize exposure to handling or loud noises during the recovery period to reduce the incidence of emergence reactions (delirium, thrashing), but continue to monitor vital signs closely.
- Hemorrhage: Because ketamine can increase blood pressure, careful control of post-surgical hemorrhage (e.g., declawing) is required.
医薬品相互作用
May prolong the anesthetic actions of ketamine
May prolong the recovery time after ketamine anesthesia
Recovery rates may be prolonged and the cardiac stimulatory effects of ketamine may be inhibited; close monitoring of cardiac status is recommended
Recommended not to use ivermectin in reptiles within 10 days of ketamine
May cause enhanced or prolonged respiratory depression
May induce severe hypertension and tachycardia; beta-blockers may be of benefit in treating these effects
Synergistic anaesthesia and prevention of muscle hypertonicity. Reversal of the alpha-2 agonist must be delayed until 45 minutes after ketamine administration to prevent unopposed ketamine excitation.
Synergistic anaesthesia and prevention of ketamine-induced skeletal muscle hypertonicity.
監視
- Level of anesthesia and analgesia
- Respiratory function
- Cardiovascular status (heart rate, rhythm, blood pressure)
- Eyes (monitor to prevent drying or injury)
- Body temperature (monitor for hyperthermia or hypothermia)
- Heart rate and rhythm
- Respiratory rate and depth
- Depth of anaesthesia
- Corneal lubrication status
- Quality of recovery (monitor for dysphoria)
薬物動態
半減期
吸収
After IM injection in the cat, peak levels occur in approximately 10 minutes. Sublingual spray in cats is absorbed enough to have pharmacologic action.
分布
Distributed into all body tissues rapidly, with highest levels found in the brain, liver, lung, and fat. Plasma protein binding is approximately 50% in the horse, 53% in dogs, and 37-53% in cats.
代謝
In most species, metabolized in the liver principally by demethylation and hydroxylation. One active metabolite, nor-ketamine, has 10-30% of the activity of the parent compound. In cats, ketamine is almost exclusively excreted unchanged.
消失
Eliminated primarily in the urine. Redistribution out of the CNS is more of a factor in determining duration of anesthesia than is the elimination half-life.
過剰投与
Ketamine has a wide therapeutic index (approximately 5 times greater than pentobarbital).
- Signs of Toxicity: When given too rapidly or in excessive doses, significant respiratory depression may occur.
- Treatment: Treatment using mechanically assisted respiratory support is recommended over the use of analeptic agents. In cats, yohimbine combined with 4-aminopyridine has been suggested for use as a partial antagonist.
製品
製剤
- Injection: 10 mg/mL
- Injection: 50 mg/mL
- Injection: 100 mg/mL
- Injectable: 100 mg/ml solution
動物用医薬品
- Ketamine HCl for Injection: 100 mg/mL in 10 mL vials (Ketaject, Ketaset, Keta-sthetic, Vetalar, VetaKet)
- Anaestamine 100 mg/ml injection
- Anesketin 100 mg/ml injection
- Ketaset 100 mg/ml injection
- Ketavet 100 mg/ml injection
- Narketan-10 100 mg/ml injection
- Vetalar-V 100 mg/ml injection
ヒト用医薬品
- Ketamine HCl Injection: 10 mg/mL in 20 mL vials
- Ketamine HCl Injection: 50 mg/mL in 10 mL vials
- Ketamine HCl Injection: 100 mg/mL in 5 mL vials (Ketalar)
規制ステータス
POM-V CD SCHEDULE 2
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Store between 15-30°C (59-86°F) and protect from light. Solution may darken upon prolonged exposure to light, which does not affect potency. Do not use if precipitates appear. Do not mix with barbiturates or diazepam in the same syringe or IV bag as precipitation may occur.
飼主向け情報
重要：ケタミンは規制薬物であり、臨床環境で獣医療従事者によってのみ投与されます。
- 目のケア：この薬の作用中、ペットの目は開いたままになることがあります。獣医療チームは、乾燥や怪我を防ぐために保護用の眼軟膏を塗布します。
- 回復期：回復中は、ペットを静かで薄暗い環境に保ってください。薬の効果が切れる際の驚愕反応、不規則な動き、または幻覚を防ぐために、大きな音、突然の動き、および過度の接触を最小限に抑えてください。
- 注意すべき点：異常なけいれん、長引くふらつき、または異常な行動がないか観察し、獣医師に報告してください。
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