VetSheet

レベチラセタム

Levetiracetam

S-Etriacetam / Pyrrolidone-derivative

抗てんかん薬POIVRectal犬猫

別名: Keppra XR · Desitrend · S-Etriacetam · UCB-22059 · UCBL059 · S-Etiracetam

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

20 mg/kg PO every 8 hoursPO· q8h
— 🐕

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。

動物種別用量

🌎 NA — North America🌍 EU — Europe

犬

適応用量経路頻度期間地域
As an add-on treatment for epilepsy in dogs refractory to phenobarbital and bromides20 mg/kg PO every 8 hoursPOq8h—🌎 NA
As an add-on treatment for epilepsy in dogs refractory to phenobarbital and/or bromides7.1-23.8 mg/kg PO every 8 hoursPOq8h—🌎 NA
Seizure management10-20 mg/kg PO q8hPOq8h—🌎 NA
Seizure managementInitially, 20 mg/kg PO q8h. May increase dose in 20 mg/kg increments until efficacy achieved, side effects become apparent, or the drug becomes cost prohibitive.POq8h—🌎 NA
Seizure management20 mg/kg PO q8h; may also be given as an IV bolus (20 mg/kg).PO/IVq8h—🌎 NA
Single-dose pharmacokinetic study60 mg/kg IV bolus doseIVOnce—🌎 NA
For status epilepticusInitially, lorazepam at 0.2 mg/kg IV once, followed by a bolus IV loading dose of levetiracetam at 60 mg/kg.IVOnce—🌎 NA
  • Single-dose pharmacokinetic study: Well tolerated and achieves plasma drug concentrations within or above the therapeutic range reported for humans for at least 8 hours.

猫

適応用量経路頻度期間地域
As an add-on to phenobarbital treatment for epilepsyInitially, 20 mg/kg PO three times daily; slowly increase to effectPOTID—🌎 NA
As an adjunct to phenobarbital in suspected idiopathic epilepsyInitially, 20 mg/kg PO three times daily. Monitor as below. If ineffective, increase dose in 20 mg/kg increments.POTID—🌎 NA

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。

診察中ですか？VetSheet の AI が薬剤・用量・投与期間を構造化された診察記録に直接記入します。VetSheet の仕組みを見る

概要

​レベチラセタム​は、主に獣医療において補助療法として使用される、構造的にユニークな新規の抗てんかん薬です。

  • ​犬：​ フェノバルビタールや臭化カリウムが禁忌または忍容性が低い場合、あるいは難治性てんかんの三次選択薬として使用されます。犬では長期投与により効果が減弱する「ハネムーン効果」が見られることがある点に注意が必要です。
  • ​猫：​ 通常、フェノバルビタールで十分な効果が得られない場合の二次追加薬として、またはフェノバルビタールに忍容性がない場合の単剤療法として使用されます。

​臨床のポイント：​ 肝臓での代謝がごくわずかであり、シトクロムP450酵素系に依存しないため、肝機能障害のある患者に非常に適しています。ただし、半減期が短いため頻回（1日3回）の投薬が必要であり、飼い主にとって負担になることがあります。

作用機序

The exact mechanism of levetiracetam's antiseizure activity is not fully elucidated, but it is distinct from traditional anticonvulsants (which typically affect GABA or ion channels).

  • Binds specifically to ​Synaptic Vesicle Protein 2A (SV2A)​ in the central nervous system.
  • Binding to SV2A → modulates neurotransmitter release into the synaptic cleft → selectively prevents hypersynchronization of epileptiform burst-firing and propagation of seizure activity.
  • It does not affect normal neuronal excitability.

安全性・警告

禁忌

  • Hypersensitivity to levetiracetam or any of its components
  • Severe renal disease

有害事象

  • Sedation (most common in dogs)
  • Lethargy (most common in cats)
  • Decreased appetite (most common in cats)
  • Behavior changes
  • Gastrointestinal effects
  • Sedation (dogs)
  • Ataxia (dogs)
  • Reduced appetite (cats)
  • Hypersalivation (cats)
  • Lethargy (cats)

注意事項

​Renal Impairment:​ Clearance is primarily renal (glomerular filtration and active tubular secretion). Dosage amounts or intervals must be adjusted in patients with decreased creatinine clearance.

  • ​Pregnancy/Nursing:​ FDA Category C. High doses in animal models showed embryofetal mortality and minor skeletal abnormalities. Excreted in maternal milk; use with caution in nursing patients.
  • ​Withdrawal:​ Abrupt discontinuation may precipitate withdrawal seizures; taper slowly if discontinuing.

医薬品相互作用

NSAIDs (naproxen, ketorolac)

May increase the risk for seizures (reported in humans; veterinary significance unclear).

PhenobarbitalModerate

Significantly increases levetiracetam clearance and reduces its half-life in dogs (from 3.43 hrs to 1.73 hrs); dosage adjustments may be required.

監視

  • Therapeutic drug monitoring (target range 5-45 mcg/mL) approximately one week after starting, then every 6-12 months (primarily to adjust dosage)
  • Seizure activity log (frequency, duration, severity)
  • Routine CBC and basic metabolic panel every 6 months
  • Adverse effects (sedation, lethargy, appetite changes)
  • Seizure frequency and severity
  • Renal function (BUN, Creatinine, SDMA) especially in older patients
  • Therapeutic drug monitoring is rarely required but can be performed

薬物動態

半減期

猫~3 hours (wide inter-patient variation)犬2-5 hours

吸収

Well absorbed after oral dosing; peak levels occur in about 2 hours in dogs and cats. In humans, food delays the rate but not the extent of absorption.

分布

Volume of distribution is about 0.9 L/kg in dogs. Less than 10% bound to plasma proteins in humans.

代謝

Not extensively metabolized. The acetamide group is enzymatically hydrolyzed to an inactive carboxylic acid metabolite. Hepatic CYP P450 isoenzymes are not involved.

消失

Primarily excreted unchanged via renal mechanisms (glomerular filtration and active tubular secretion). Clearance is significantly reduced in renal impairment.

過剰投与

Levetiracetam is a relatively safe agent.

  • ​Dogs:​ Doses of 1200 mg/kg/day (~20x therapeutic dose) caused only salivation and vomiting.
  • ​Humans:​ Doses of 6000 mg/kg caused drowsiness. Other reported effects include depressed consciousness, agitation, aggression, and respiratory depression.
  • ​Treatment:​ Basically supportive. The drug can be removed with hemodialysis. Contact an animal poison control center for significant overdoses.

製品

製剤

  • Oral Tablets (film-coated, scored)
  • Extended-Release Oral Tablets
  • Concentrate for Injection
  • Oral tablets: 250 mg, 500 mg, 750 mg, 1 g
  • Oral solution: 100 mg/ml (300 ml bottle)
  • Coated granules: 250 mg/sachet
  • Injectable solution: 100 mg/ml (5 ml vial)
  • Infusion solution: formulated with sodium chloride at 500 mg/100 ml, 1000 mg/100 ml, 1500 mg/100 ml

ヒト用医薬品

  • Levetiracetam Oral Tablets (film-coated, scored): 250 mg, 500 mg, 750 mg & 1000 mg (Keppra, generic)
  • Levetiracetam Extended-Release Oral Tablets: 500 mg & 750 mg (Keppra XR)
  • Levetiracetam Oral Solution: 100 mg/mL (Keppra, generic)
  • Levetiracetam Concentrate for Injection: 100 mg/mL in 5 mL single-use vials (Keppra)
  • Desitrend
  • Keppra (250 mg, 500 mg, 750 mg, 1 g tablets; 100 mg/ml oral solution; 100 mg/ml IV solution)

規制ステータス

European Union✓ 承認済み処方箋医薬品EMA
🐕 Dogs🐈 Cats

POM (Prescription Only Medicine)

United Kingdom✓ 承認済み処方箋医薬品VMD
🐕 Dogs🐈 Cats

POM (Prescription Only Medicine)

規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

保管・安定性

Tablets or oral solution should be stored at 25°C (77°F); excursions permitted to 15-30°C (59-86°F).

飼主向け情報

  • ​厳密な投薬スケジュール​：この薬は指示通りに、通常​8時間ごと（1日3回）​に投薬する必要があります。投薬を忘れると発作が起きる可能性があります。
  • ​副作用​：初期には眠気、無気力、食欲低下が見られることがありますが、通常はペットが薬に慣れるにつれて改善します。
  • ​発作日記​：獣医師が用量を調整する際の参考となるよう、発作の日時、持続時間、重症度を詳細に記録してください。

​自己判断で中止しない​：急に投薬をやめると、重篤で生命に関わる発作を引き起こす危険があります。用量を変更する前には必ず獣医師に相談してください。

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。