リドカイン
Lidocaine
Lidocaine hydrochloride
別名: Xylocaine MPF · EMLA · Intubeaze · Lignadrin · Lignol · Locovetic · Lidoderm · lidocaini hydrochloridum · lignocaine hydrochloride · Lidocainum
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Regional anesthesia (extra-label) — CRI via peritoneal wound catheter
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 (5)
- 1. Lidocaine formulation concentration, administration volume, site of administration, administration technique (eg, aspiration prior to injection), and underlying patient condition(s) are important interrelated factors that determine lidocaine’s safe and effective use.
- 2. All dosages below use 2% lidocaine (20 mg/mL) unless otherwise specified.
- Infiltration: dilute to 0.5% concentration (for each 1 mL of lidocaine 2% solution, dilute with 3 mL sterile water)
- Regional anesthesia (extra-label):
- Lidocaine should be stored at room temperature, at 15°C to 30°C (59°F-86°F).
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
リドカインは、多用途のアミド系局所麻酔薬およびクラスIB抗不整脈薬です。獣医療においては、局所・区域麻酔だけでなく、心室性不整脈、神経障害性疼痛、消化管運動障害の管理のために全身投与としても広く利用されています。
主な臨床応用：
- 抗不整脈治療： 犬の急性で生命を脅かす心室頻拍（VT）および心室期外収縮（VPC）に対する第一選択薬です。
- 全身性鎮痛： 定速点滴（CRI）として投与され、オピオイドやケタミン（例：MLK CRI）と併用されることが多く、強力な補助鎮痛を提供し、吸入麻酔薬の最小肺胞濃度（MAC）を低下させ、神経障害性疼痛や痛覚過敏を軽減します。
- 消化管運動促進および抗炎症作用： 馬では、術後イレウスの治療や予防、および活性酸素種（ROS）の消去による虚血再灌流障害の軽減のために全身性リドカインが頻繁に使用されます。
臨床上のポイント： 猫はリドカインの心機能抑制および中枢神経系（CNS）の毒性作用に対して非常に敏感です。猫への全身投与には議論があり、極めて慎重な取り扱いと正確な用量設定が必要です。
作用機序
Lidocaine exerts its effects through multiple mechanisms depending on the target tissue:
- Antiarrhythmic Action (Class IB): Lidocaine binds to and blocks fast voltage-gated sodium channels (Nav1.5) in the myocardium. It exhibits use-dependent and state-dependent blockade, meaning it preferentially binds to sodium channels in their inactive state (which occurs during depolarization). This action → attenuates phase 4 diastolic depolarization → decreases automaticity → suppresses ectopic ventricular pacemakers without significantly affecting the SA or AV nodes at therapeutic levels.
- Local Anesthetic/Analgesic Action: Blocks neuronal voltage-gated sodium channels, preventing the influx of sodium required for the initiation and conduction of action potentials in peripheral nerves. Systemically, it reduces ectopic firing from damaged afferent neurons, providing relief from neuropathic pain.
- Prokinetic & Cytoprotective Action: The exact mechanism for enhancing intestinal motility (especially in equine ileus) is multifactorial, likely involving suppression of sympathetic inhibitory reflexes, direct anti-inflammatory effects, and acting as a scavenger of reactive oxygen species (ROS) to prevent lipid peroxidation and reperfusion injury.
安全性・警告
禁忌
- Known hypersensitivity to amide-class local anesthetics
- Severe SA, AV, or intraventricular heart block (unless artificially paced)
- Adams-Stokes syndrome
- Intravenous use of lidocaine products containing epinephrine
- Continuous rate infusion (CRI) in cats during the perioperative period (due to negative haemodynamic effects)
- Intravenous administration of lidocaine solutions containing adrenaline
- Use of adrenaline-containing solutions for complete ring block of an extremity (danger of ischaemic necrosis)
有害事象
- CNS toxicity (dose-related): drowsiness, depression, ataxia, nystagmus, muscle tremors, seizures
- Gastrointestinal: nausea and vomiting (usually transient)
- Cardiovascular: hypotension (especially with rapid IV bolus), bradycardia, PR and QRS interval prolongation, circulatory collapse at toxic doses
- Cats: heightened risk of severe cardiodepression and CNS signs
- Muscle fasciculations
- Laryngeal oedema (in cats, associated with CFC propellants in unlicensed aerosols)
注意事項
Use with extreme caution in cats due to heightened sensitivity to CNS and cardiodepressant effects. Use cautiously in patients with liver disease, congestive heart failure, shock, hypovolemia, severe respiratory depression, or marked hypoxia. Patients susceptible to malignant hyperthermia require intensified monitoring. NEVER administer lidocaine containing epinephrine intravenously.
医薬品相互作用
Lidocaine infusions reduce MAC requirements. Additive cardiodepression may occur, especially in cats.
May cause additive or antagonistic cardiac effects; enhanced risk of toxicity.
May decrease lidocaine clearance, increasing lidocaine levels and effects.
Diuretic-induced hypokalemia may reduce the antiarrhythmic efficacy of lidocaine.
May induce hepatic enzymes, increasing lidocaine metabolism and decreasing its serum levels.
May decrease hepatic blood flow and lidocaine clearance, increasing lidocaine levels.
Large doses of lidocaine may prolong succinylcholine-induced apnea.
May cause increased myocardial depression
監視
- Continuous ECG monitoring (especially during IV bolus or CRI)
- Signs of CNS toxicity (ataxia, tremors, seizures)
- Blood pressure (monitor for hypotension)
- Serum lidocaine levels if available (Therapeutic range: 1-6 micrograms/mL)
- ECG (especially during IV therapy for arrhythmias)
- Heart rate
- CNS signs (monitor for fasciculations or seizures)
薬物動態
半減期
吸収
High first-pass effect makes it ineffective orally. Following a therapeutic IV bolus, onset of action is generally within 2 minutes with a duration of 10-20 minutes.
分布
Rapidly redistributed from plasma into highly perfused organs (kidney, liver, lungs, heart), then widely throughout body tissues. High affinity for fat and adipose tissue. Bound to plasma proteins (primarily alpha1-acid glycoprotein). Vd is approximately 4.5 L/kg in dogs.
代謝
Rapidly metabolized in the liver to active metabolites (MEGX and GX).
消失
Less than 10% of a parenteral dose is excreted unchanged in the urine.
過剰投与
In dogs, toxicity may result if serum levels exceed 8 micrograms/mL.
- Clinical Signs: Ataxia, nystagmus, depression, seizures, bradycardia, hypotension, and at very high levels, circulatory collapse.
- Management: Because lidocaine is rapidly metabolized, simply stopping the infusion or reducing the rate (with close monitoring) is often sufficient for minor signs.
- Seizure Control: Treat seizures or excitement with diazepam or a short/ultrashort-acting barbiturate. > Warning: Longer-acting barbiturates (e.g., pentobarbital) should be avoided.
- Cardiovascular Support: Treat circulatory depression with IV fluids, pressor agents, and initiate CPR if necessary.
製品
製剤
- Injection: 0.5%, 1%, 1.5%, 2%, 4% solutions
- Premixed IV infusion solutions (with D5W)
- Topical: patches, ointments, creams, lotions, gels, sprays, and jellies
- Injectable: 1% solution
- Injectable: 2% solution (some contain adrenaline)
- Topical: 2% solution
- Topical: 4% solution
- Topical: 2.5% cream (with prilocaine)
- Transdermal: 5% patches
動物用医薬品
- Lidocaine HCl for Injection: 2% (20 mg/mL) in 100 mL & 250 mL multi-use vials
- Intubeaze 2% topical solution
- Lignadrin injectable
- Lignol injectable
- Locaine injectable
- Locovetic injectable
ヒト用医薬品
- Lidocaine Hydrochloride Injection: 0.5%, 1%, 1.5%, 2% & 4% in various vials, ampules, and syringes
- Lidocaine Hydrochloride with Dextrose Injection: 1.5% or 5% with 7.5% dextrose
- Premixed IV infusions in D5W (2 mg/mL, 4 mg/mL, 5 mg/mL)
- Topical liquids, patches, ointments, creams, lotions, gels, sprays, and jellies
- EMLA 2.5% cream (with prilocaine)
- Xylocaine 4% topical solution
- Lidoderm 5% transdermal patch
規制ステータス
POM-V classification
POM-V classification
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Store at temperatures less than 40°C, preferably between 15-30°C. Avoid freezing.
飼主向け情報
リドカインは強力な薬剤であり、通常は動物病院で獣医療の専門家によってのみ使用されます。
- 目的： 生命を脅かす異常な心拍リズム（不整脈）を修正するため、または大手術や外傷後に持続的な痛みの管理（他の鎮痛薬と混合されることが多い）を提供するために使用されます。
- モニタリング： 薬は直接血流に投与されるため、用量が安全で効果的であることを確認するために、ペットは厳密に監視されます（通常は心電図や血圧測定が行われます）。
- 副作用： 副作用が発生した場合でも、通常は軽度であり、薬の投与速度を調整すればすぐに治まります。ペットが起きている場合は、眠気、筋肉の震え、吐き気などの兆候に注意してください。
VetSheet医薬品リファレンスは獣医専門家の臨床意思決定支援を目的としており、専門的判断または製造業者の最新医薬品情報の代替にはなりません。