VetSheet

異丙嗪

Promethazine

Promethazine hydrochloride

吩噻嗪類抗組織胺 / 止吐藥POIMIVRectal狗貓

別名: Phenergan · Phenadoz · Promethegan · Promethazine HCl · Lilly 01516 · PM 284 · RP 3277 · prometazina · Promethazine hydrochloride · Promethazini hydrochloridum

由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本

2 mg/kg PO or IM once dailyPO/IM· q24h
— 🐕

劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。

各物種劑量

🌎 NA — North America🌍 EU — Europe

狗

適應症劑量途徑頻次療程地區
As an antiemetic2 mg/kg PO or IM once dailyPO/IMq24h—🌎 NA
As an antihistamine0.2-0.4 mg/kg PO three to four times a dayPOq6-8h—🌎 NA
As an antihistamine1-2 mg/kg PO q12hPOq12h—🌎 NA

貓

適應症劑量途徑頻次療程地區
As an antiemetic2 mg/kg PO or IM once dailyPO/IMq24h—🌎 NA
As an antihistamine0.2-0.4 mg/kg PO three to four times a dayPOq6-8h—🌎 NA
As an antihistamine1-2 mg/kg PO q12hPOq12h—🌎 NA

劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。

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概覽

異丙嗪是一種吩噻嗪類衍生物，在獸醫學中主要用作止吐藥和抗組織胺藥。

  • ​主要用途​：偶爾用於控制犬貓的噁心和嘔吐，也曾嘗試用於治療異位性皮膚炎犬隻的搔癢（但對後者的療效通常不佳）。
  • ​藥理特徵​：雖然在結構上與乙醯丙嗪 (acepromazine) 等鎮靜劑相似，但異丙嗪的特點在於其強效的抗組織胺特性，同時兼具止吐、抗膽鹼、鎮靜和輕微的局部麻醉作用。

​臨床提示​：與較新的標靶止吐藥（如 maropitant、ondansetron）或標準抗組織胺藥（如 diphenhydramine）相比，異丙嗪在現代獸醫臨床中的處方相對較少，這主要是因為它可能引起鎮靜和錐體外症候群等副作用。

作用機轉

Promethazine exerts its effects through competitive antagonism at multiple receptor sites centrally and peripherally:

  • H1-Receptor Antagonism: Competitively blocks histamine at H1 receptors → reduces allergic responses and pruritus.
  • D2-Dopaminergic Antagonism: Blocks dopamine receptors in the Chemoreceptor Trigger Zone (CRTZ) of the medulla → provides central antiemetic effects.
  • Muscarinic Antagonism: Blocks acetylcholine at muscarinic receptors → contributes to antiemetic efficacy and causes anticholinergic side effects (e.g., dry mouth).
  • Alpha-1 Adrenergic Antagonism: Blocks peripheral alpha-1 receptors → can lead to vasodilation and subsequent hypotension.

安全性與警告

禁忌症

  • Hypovolemia or shock (due to hypotensive effects)
  • Tetanus or strychnine intoxication (due to extrapyramidal effects)
  • Human label black box warning: Contraindicated in children < 2 years old (fatal respiratory depression)
  • Known hypersensitivity to phenothiazines
  • Severe central nervous system depression
  • Comatose patients
  • Use with caution in patients with seizure disorders
  • Use with caution in patients with severe hepatic or cardiovascular disease

不良反應

  • Sedation or lethargy
  • Anticholinergic effects (dry mouth, urinary retention, decreased GI motility)
  • Hypotension (especially with rapid IV administration or in hypovolemic patients)
  • Extrapyramidal signs (tremors, rigidity, torticollis) - rare but possible
  • Sedation / Lethargy
  • Dry mucous membranes (anticholinergic effect)
  • Tachycardia
  • Paradoxical excitation (especially in cats)
  • Gastrointestinal disturbances

注意事項

Use cautiously and at smaller doses in animals with hepatic dysfunction, cardiac disease, or general debilitation. Animals may require lower dosages of general anesthetics following phenothiazine administration. Use with extreme caution in very young or severely debilitated animals. Promethazine can cause false-positive results for salicylates in urine and false-positive/negative results for chorionic gonadotropin in urine.

藥物交互作用

Antacids

May cause reduced GI absorption of oral phenothiazines.

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

May cause reduced GI absorption of oral phenothiazines.

Atropine & other anticholinergics

May have additive anticholinergic effects when used with promethazine.

CNS Depressant Agents (barbiturates, narcotics, anesthetics)

May cause additive CNS depression if used with phenothiazines.

EpinephrineMajor

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.

Monoamine Oxidase Inhibitors (MAOIs)

May potentiate extrapyramidal effects.

Opiates

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

Organophosphate Agents

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

CNS Depressants (e.g., opioids, barbiturates, anesthetics)Major

Additive central nervous system depression and sedation.

Anticholinergic agents (e.g., atropine, glycopyrrolate)Moderate

Additive anticholinergic effects (tachycardia, dry mouth, ileus).

監測

  • Clinical efficacy (resolution of vomiting or pruritus)
  • Degree of sedation
  • Hydration status (if vomiting persists)
  • Heart rate and rhythm
  • Blood pressure (especially with IV use)
  • Level of consciousness / CNS status
  • Respiratory rate

藥物動力學

半衰期

貓Unknown狗Unknown

吸收

Little veterinary data available. In humans, well absorbed following oral, rectal, or IM administration.

分佈

Presumed to follow general phenothiazine patterns (widely distributed, crosses blood-brain barrier).

代謝

Metabolized in the liver.

排除

Metabolites are eliminated primarily in the urine.

過量

Overdose may result in profound sedation, severe hypotension, or acute extrapyramidal clinical signs (e.g., torticollis, tremors, excessive salivation, rigidity).

  • Treatment: Supportive care is primary. Acute extrapyramidal signs have been successfully treated with injectable diphenhydramine in humans. Hypotension should be treated with IV fluids; avoid epinephrine due to the risk of epinephrine reversal (use alpha-agonists like phenylephrine if pressors are required).

可用產品

劑型

  • Oral tablets
  • Oral syrup
  • Injection (IV/IM)
  • Rectal suppositories
  • 10 mg tablet
  • 25 mg tablet
  • 1 mg/ml syrup
  • 25 mg/ml injectable solution

人用標示

  • Promethazine HCl for Injection: 25 mg/mL & 50 mg/mL in 1 mL ampules
  • Promethazine HCl Oral syrup: 1.25 mg/mL
  • Promethazine HCl Oral Tablets: 12.5 mg, 25 mg & 50 mg
  • Promethazine HCl Rectal Suppositories: 12.5 mg, 25 mg, & 50 mg
  • Phenergan 10 mg tablets
  • Phenergan 25 mg tablets
  • Phenergan 1 mg/ml syrup
  • Phenergan 25 mg/ml injectable solution

各地核准狀態

European Union✓ 已核准處方藥 · POMEMA

Available as a human prescription product (POM).

United Kingdom✓ 已核准處方藥 · POMVMD

Phenergan is a POM (Prescription Only Medicine) in the UK.

暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

儲存與穩定性

Store tablets at room temperature (20-25°C) in tight, light-resistant containers. Syrup should be stored at 15-25°C and protected from light. Injection should be stored at room temperature (20-25°C) and protected from light; do not use if precipitate forms or solution is discolored. Suppositories should be stored in the refrigerator (2-8°C). Promethazine can adsorb to plastic IV bags and tubing.

飼主須知

異丙嗪用於幫助控制噁心和嘔吐，或偶爾用於治療過敏反應。

  • ​口乾​：此藥物可能會導致口乾。您可以透過在寵物的舌頭上滴少量水並持續 10-15 分鐘來緩解此症狀。
  • ​鎮靜作用​：可能會引起嗜睡、鎮靜或輕微的行為改變。如果這些影響很嚴重或令您擔憂，請聯繫您的獸醫師。
  • ​何時聯繫獸醫​：持續的嘔吐或腹瀉可能很嚴重；如果寵物的臨床症狀沒有改善，請聯繫您的獸醫師。
  • ​危險信號​：如果您的動物表現出異常的抽搐動作、顫抖或變得僵硬，請立即聯繫您的獸醫師。

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