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プロクロルペラジン

Prochlorperazine

Prochlorperazine (base, edisylate, maleate)

フェノチアジン系制吐薬IMSCPORectalIV犬猫

別名: Compazine · Compro · Prorazin · Stemetil · Tementil · chlormeprazine · prochlorpemazine

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

0.5 mg/kgIM or SC· 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 antiemetic0.5 mg/kgIM or SCq8h—🌎 NA
As an antiemetic0.1 mg/kgIMq6-8h—🌎 NA
As an antiemetic0.1-0.5 mg/kgIM or SCq6-8h—🌎 NA
All uses (motion sickness, emesis)0.1-0.5 mg/kgIV/IM/SCq6-8h—🌍 EU
All uses (motion sickness, emesis)0.5-1 mg/kgPOq8-12h—🌍 EU
  • As an antiemetic: Ensure adequate hydration
  • As an antiemetic: Use with extreme caution in dehydrated or hypotensive animals

猫

適応用量経路頻度期間地域
As an antiemetic0.5 mg/kgSC or IMthree times a day—🌎 NA
As an antiemetic0.5 mg/kgIM or SCq8h—🌎 NA
As an antiemetic0.1-0.5 mg/kgIM or SCq6-8h—🌎 NA
All uses (motion sickness, emesis)0.1-0.5 mg/kgIV/IM/SCq6-8h—🌍 EU
All uses (motion sickness, emesis)0.5-1 mg/kgPOq8-12h—🌍 EU
  • As an antiemetic: Ensure adequate hydration

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

プロクロルペラジンは強力な​フェノチアジン系制吐薬​であり、獣医療では主に犬や猫の重度の悪心および嘔吐を抑えるために使用されます。

歴史的には獣医専用の配合剤（抗コリン薬を含むDarbazine®など）として広く使用されていましたが、現在では人体用製剤を適応外使用（オフラベル）することが一般的です。

​臨床のポイント：​ 広範な受容体拮抗作用を持つため、中枢性嘔吐に対して非常に有効です。しかし、顕著な鎮静作用やαアドレナリン受容体遮断（低血圧を引き起こす）のリスクがあるため、通常はマロピタントやオンダンセトロンなどの新しい標的制吐薬が無効または利用できない場合に限定して使用されます。また、軽度の鎮静作用と弱い抗コリン作用も併せ持ちます。

作用機序

Prochlorperazine exerts its antiemetic effects primarily by acting on the brain's emetic center and the ​Chemoreceptor Trigger Zone (CRTZ)​. Its broad-spectrum efficacy is due to the antagonism of multiple receptor types:

  • Dopaminergic (D2) Antagonism → Blocks dopamine signaling in the CRTZ, providing the primary antiemetic effect.
  • Histaminergic (H1) & Cholinergic (M1) Antagonism → Contributes to anti-motion sickness efficacy and mild antispasmodic effects in the GI tract.
  • Alpha-1 Adrenergic Antagonism → Causes peripheral vasodilation, which is responsible for the primary adverse effect of hypotension.

It also has strong extrapyramidal effects due to central dopamine blockade in the basal ganglia.

安全性・警告

禁忌

  • Hypovolemia or dehydration
  • Shock
  • Tetanus
  • Strychnine intoxication
  • Hepatic dysfunction (use with caution)
  • Cardiac disease (use with caution)

有害事象

  • Sedation
  • Hypotension
  • Muscle fasciculations and tremors (extrapyramidal signs)
  • Prolactin release
  • Depression
  • Extrapyramidal reactions (rigidity, tremors, weakness, restlessness)

注意事項

Animals may require lower dosages of general anesthetics following phenothiazine administration. Use cautiously and at smaller doses in animals with hepatic dysfunction, cardiac disease, or general debilitation. Because of hypotensive effects, it is relatively contraindicated in patients with hypovolemia, dehydration, or shock. May exacerbate depression in patients with pre-existing CNS depression. Do not use for tetanus or strychnine intoxication due to extrapyramidal effects. Use with caution in very young or debilitated animals.

医薬品相互作用

AntacidsModerate

May cause reduced GI absorption of oral phenothiazines

Antidiarrheal mixtures (e.g., Kaolin/pectin, bismuth subsalicylate)

May cause reduced GI absorption of oral phenothiazines

CNS Depressant Agents (barbiturates, narcotics, anesthetics)

May cause additive CNS depression if used with phenothiazines

Dopamine

Phenothiazines may decrease pressor effects

Epinephrine

Phenothiazines block alpha-adrenergic receptors; concomitant epinephrine can lead to unopposed beta-activity causing vasodilation and increased cardiac rate (epinephrine reversal)

Metoclopramide

Phenothiazines may potentiate the extrapyramidal effects of metoclopramide

Opiates

May enhance the hypotensive effects of the phenothiazines; dosages of prochlorperazine may need to be reduced

Organophosphate Agents

Phenothiazines should not be given within one month of worming with these agents as their effects may be potentiated

Paraquat

Toxicity of the herbicide paraquat may be increased by prochlorperazine

Phenytoin

Metabolism may be decreased if given concurrently with phenothiazines

Physostigmine

Toxicity may be enhanced by prochlorperazine

Procaine

Activity may be enhanced by phenothiazines

PropranololModerate

Increased blood levels of both drugs may result if administered together

Warfarin

Prochlorperazine may decrease anticoagulant effect

CNS depressants (anaesthetics, narcotic analgesics)Major

May cause additive CNS depression

Antidiarrhoeal preparations (bismuth subsalicylate, kaolin/pectin)Moderate

May reduce GI absorption of oral phenothiazines

Adrenaline (Epinephrine)Major

Phenothiazines block alpha-adrenergic receptors, leading to unopposed beta activity causing vasodilation and increased cardiac rate

監視

  • Cardiac rate, rhythm, and blood pressure (if indicated and possible to measure)
  • Anti-emetic/anti-spasmodic efficacy
  • Hydration and electrolyte status
  • Body temperature (especially if ambient temperature is very hot or cold)
  • Heart rate and rhythm
  • CNS status (sedation level, extrapyramidal signs)
  • Liver function (with prolonged use)

薬物動態

吸収

Little specific information available; likely follows general patterns of other phenothiazine agents.

分布

Likely follows general patterns of other phenothiazines. A related compound (chlorpromazine) is detected in maternal milk with a milk-to-plasma ratio of 0.5-0.7 or less.

代謝

Hepatic (assumed based on phenothiazine class).

消失

Likely follows general patterns of other phenothiazine agents.

過剰投与

Overdose generally presents as an exaggeration of adverse effects, particularly profound sedation, hypotension, and extrapyramidal clinical signs (such as torticollis, severe tremors, muscle rigidity, and excessive salivation).

​Treatment:​ Acute extrapyramidal signs have been successfully treated with injectable diphenhydramine in humans. Hypotension should be treated with intravenous fluids; avoid epinephrine due to the risk of "epinephrine reversal" causing further vasodilation.

製品

製剤

  • Injection (edisylate salt)
  • Oral tablets (maleate salt)
  • Rectal suppositories (base)
  • 12.5 mg/ml injectable solution (1 ml ampoule)
  • 3 mg oral tablet
  • 5 mg oral tablet
  • 5 mg/5 ml oral syrup

動物用医薬品

  • None currently available (Darbazine® is no longer marketed in the USA)

ヒト用医薬品

  • Prochlorperazine for Injection: 5 mg/mL in 2 mL vials
  • Prochlorperazine Tablets: 5 mg & 10 mg (as maleate)
  • Prochlorperazine Suppositories: 25 mg (as base)
  • Stemetil 12.5 mg/ml injection
  • Stemetil 3 mg tablets
  • Stemetil 5 mg tablets
  • Stemetil 5 mg/5 ml syrup

規制ステータス

European Union✗ 未承認処方箋医薬品EMA

Not a first choice; used off-label under the prescribing cascade as maropitant and metoclopramide are authorized.

United Kingdom✗ 未承認処方箋医薬品 · POMVMD

POM (Prescription Only Medicine). Used under the cascade.

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

保管・安定性

Store in tight, light-resistant containers at room temperature. Avoid temperatures above 40°C and below freezing. A slight yellowing of the oral or injectable solution has no effects on potency or efficacy, but do not use if a precipitate forms or the solution is substantially discolored.

飼主向け情報

​重要な安全上の注意：​ 投薬後少なくとも1時間はペットを注意深く観察してください。この薬は眠気やふらつきを引き起こす可能性があるため、安全で静かな環境に置いてください。

  • ​口の渇き：​ ペットが口をくちゃくちゃさせることに気づくかもしれません。ペットの舌に少量の水を10〜15分間与えることで和らげることができます。
  • ​尿の色の変化：​ この薬により、尿がピンク色または赤褐色に変色することがありますが、これは無害であり正常な反応ですので心配いりません。
  • ​獣医師に連絡するタイミング：​ 長引く嘔吐や下痢は深刻な場合があります。症状が改善しない場合は獣医師に連絡してください。ペットが異常な行動をとったり、体が硬直したり、その他の異常な体の動きや震えを示した場合は、​直ちに獣医師の診察を受けてください​。

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。