アセプロマジン
Acepromazine
Acepromazine maleate
別名: PromAce · Aceproject · Aceprotabs · Plegicil · Notensil · Atravet · Acecare · ACP · Acetylpromazine maleate
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
確認済み・計算対象外のエビデンス確認済み・計算対象外のエビデンス (1)
エビデンス表示のみ（自動計算対象外）
Tranquilization
a) Tranquilization: 0.25 – 0.75 mg/kg IM or SC 46 ; the lower to mid-range of the dosage is generally adequate.
必ず考慮する臨床コンテキスト (4)
- 1. Acepromazine does not provide analgesia; addition of an analgesic agent is required when pain relief is needed.
- All dosages are extra-label.
- Store tablets and injection protected from light at 20°C to 25°C (68°F-77°F), with excursions permitted between 15°C and 30°C (59°F-86°F). Tablets should be stored in tight containers. There is no limit to the number of vial punctures throughout the full expiry period. 1
- 2. Administer IV doses slowly; allow at least 15 minutes for onset of action. 1
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
アセプロマジンは、獣医学において古くから広く利用されているフェノチアジン系神経遮断薬であり、主にその確実な鎮静および精神安定作用のために使用されます。
臨床上の重要なポイント：
- 鎮痛作用なし： アセプロマジンには鎮痛効果が全くありません。痛みを伴う処置には、適切な鎮痛薬（オピオイドなど）との併用（神経遮断鎮痛）が必須です。
- 心血管系への影響： α1受容体遮断作用による強力な血管拡張薬であり、頻繁に低血圧を引き起こします。循環血液量減少、ショック、または血行動態が不安定な患者には使用を避けるべきです。
- 犬種の感受性： 超大型犬やサイトハウンド（グレイハウンドなど）は非常に敏感です。MDR1（ABCB1）遺伝子変異を持つ犬（コリー、オーストラリアン・シェパードなど）は、大幅な用量減量（25〜50％）が必要です。
- 馬に関する注意事項： 牡馬において持続的な陰茎脱出または持続勃起症を引き起こす可能性があり、陰茎牽引筋の永久的な麻痺につながる恐れがあります。
歴史的には旅行不安や音響恐怖症に使用されてきましたが、現代の獣医行動学者は、根本的な恐怖やパニックを軽減せずに動物を鎮静させるだけであり、音に対する感受性を高める可能性があるため、これらの状態に対する単独療法としての使用を推奨していません。
作用機序
Acepromazine exerts its effects through multiple receptor antagonisms:
- Dopamine (D2) Receptor Antagonism: Blocks postsynaptic D2 receptors in the CNS (specifically the basal ganglia and limbic system) → depresses the reticular activating system → produces sedation and tranquilization.
- Alpha-1 Adrenergic Antagonism: Blocks peripheral alpha-1 receptors → causes peripheral vasodilation → leads to hypotension and secondary hypothermia.
- Additional Blockade: Possesses varying degrees of anticholinergic (muscarinic), antihistaminic (H1), and antispasmodic effects.
- Antiemetic Effect: Blocks dopamine receptors in the Chemoreceptor Trigger Zone (CRTZ) of the medulla.
Clinical Pearl: Because of its alpha-blocking properties, administering epinephrine to an acepromazine-induced hypotensive patient can cause "epinephrine reversal" (unopposed beta-2 vasodilation), worsening the hypotension. Alpha-agonists like phenylephrine are preferred for treating severe acepromazine-induced hypotension.
安全性・警告
禁忌
- Significant cardiac disease
- Hypovolemia, hypotension, or shock
- Tetanus or strychnine intoxication
- Intra-arterial injection in horses (can cause severe CNS excitement, seizures, death)
- Use with extreme caution in very young, geriatric, or debilitated animals
- Avoid in racing animals within 4 days of a race
有害事象
- Hypotension and cardiovascular collapse
- Bradycardia (vagally mediated) or reflex tachycardia
- Hypothermia or hyperthermia
- Penile protrusion/prolapse in large animals (especially stallions)
- Prolapse of the membrana nictitans (third eyelid)
- Decreased tear production (especially in cats)
- Paradoxical excitement, restlessness, or aggression
- Transient pain at IM injection sites
- Decreased hematocrit (due to splenic sequestration of RBCs)
注意事項
Dosage Adjustments: The manufacturer's labeled dose is often considered up to 10 times higher than clinically necessary. Use lower end of dose ranges.
Breed Sensitivities:
- MDR1 Mutation: Dogs with the MDR1 (ABCB1) mutation (Collies, Australian Shepherds, etc.) require a 25% dose reduction if heterozygous, and a 30-50% reduction if homozygous.
- Giant Breeds & Sight Hounds: Extremely sensitive; require lower doses.
- Terriers: May be somewhat resistant to effects.
Administration: Give IV injections slowly. Allow at least 15 minutes for onset of action. Never inject intra-arterially in horses.
Behavioral: Use cautiously as a restraining agent in aggressive dogs; it may make the animal more prone to startle and react to noises.
Other: May cause regurgitation of ruminal contents in cattle during general anesthesia induction.
医薬品相互作用
Possible increased risk for hypothermia
May cause reduced GI absorption of oral phenothiazines
May cause reduced GI absorption of oral phenothiazines
May cause additive CNS depression if used with acepromazine
Acepromazine may impair the vasopressive action of dopamine
Acepromazine may reduce the effectiveness of emetics
Concomitant use can lead to unopposed beta-activity causing vasodilation and increased cardiac rate (epinephrine reversal)
May increase risks for extrapyramidal adverse effects
May enhance hypotensive effects; dosages of acepromazine are generally reduced when used with an opiate
Effects may be potentiated; do not give within one month of worming with these agents
Metabolism may be decreased if given concurrently
Activity may be enhanced by phenothiazines
Increased blood levels of both drugs may result
May cause additive cardiac depression
Additive CNS depression; doses of other anaesthetic drugs should be reduced when ACP is used for premedication
Unopposed beta activity causing severe vasodilation and tachycardia (due to ACP's alpha-adrenergic blockade)
Reduced GI absorption of oral phenothiazines
監視
- Cardiac rate, rhythm, and blood pressure (especially in compromised patients)
- Degree of tranquilization and sedation
- Male horses: Monitor to ensure the penis retracts and is not injured
- Body temperature (especially if ambient temperature is very hot or cold)
薬物動態
半減期
吸収
Onset of action is fairly slow, requiring up to 15 minutes following IV administration, with peak effects seen in 30-60 minutes.
分布
Fairly high volume of distribution (6.6 L/kg in horses), and is more than 99% protein bound.
代謝
Metabolized in the liver.
消失
Both conjugated and unconjugated metabolites are eliminated in the urine. Metabolites may be found in equine urine up to 96 hours after dosing.
過剰投与
The LD50 in mice is 61 mg/kg IV and 257 mg/kg PO. Dogs have survived oral dosages up to 220 mg/kg, but overdoses can cause serious hypotension, CNS depression, pulmonary edema, and hyperemia.
Clinical Signs of Toxicity:
- Dogs: Ataxia, sedation, lethargy, depression, protrusion of the third eyelid, somnolence, bradycardia, and recumbency.
- Cats: Sedation, ataxia, lethargy, protrusion of the third eyelid, and depression.
Treatment:
- Because of relatively low toxicity, most overdoses are handled by monitoring and symptomatic treatment.
- Massive oral overdoses should be treated by emptying the gut if possible.
- Hypotension: Should not be treated initially with fluids. If fluids fail to maintain BP, use alpha-adrenergic pressor agents (e.g., phenylephrine). Note: Avoid epinephrine due to the risk of "epinephrine reversal" causing further vasodilation.
- Seizures: May be controlled with barbiturates or diazepam.
- CNS Depression: Doxapram has been suggested as an antagonist to the CNS depressant effects.
製品
製剤
- Injection: 10 mg/mL
- Tablets: 5 mg, 10 mg, 25 mg
動物用医薬品
- Acepromazine Maleate for Injection: 10 mg/mL in 50 mL vials (PromAce, generic)
- Acepromazine Maleate Tablets: 5 mg, 10 mg & 25 mg (PromAce, generic)
規制ステータス
Classified as POM-V (Prescription Only Medicine - Veterinarian)
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Store protected from light. Tablets should be stored in tight containers. Acepromazine injection should be kept from freezing. Stable and efficacious for at least 180 days after mixing with ketamine and xylazine if stored at room temperature in the dark.
飼主向け情報
- 尿の変色： この薬はペットの尿を一時的にピンク色または赤褐色に変色させることがありますが、これは正常な副作用であり心配はいりません。
- 鎮痛薬ではありません： アセプロマジンは鎮静効果をもたらしますが、痛みを取り除くことはありません。ペットが痛みを伴う処置を受ける場合は、他の薬が必要になります。
- 静かな環境を保つ： ペットが眠そうに見えても、大きな音や突然の動きに驚き、予測不可能な反応を示すことがあります。薬の効き目が切れるまでは、静かで落ち着いた環境に置いてください。
- 瞬膜（第三眼瞼）： ペットの「第三眼瞼」（目頭にある膜）が目の一部を覆っていることに気づくかもしれません。これは正常な現象であり、薬の効き目が切れるとともに元に戻ります。
- 規制： 食用を目的としない犬、猫、馬への使用がFDAによって承認されています。
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。