VetSheet

フェニルプロパノールアミン

Phenylpropanolamine

Phenylpropanolamine HCl

交感神経刺激薬PO犬猫

別名: Proin · Propalin · Cystolamine · Uricon · Uriflex-PT · Urilin · PPA · dl-norephedrine · Diphenylpyraline

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

12.5-50 mg (total dose) or 1-2 mg/kg PO q8hPO· 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
Urethral sphincter hypotonus12.5-50 mg (total dose) or 1-2 mg/kg PO q8hPOq8h—🌎 NA
Urethral sphincter hypotonusDogs weighing less than 40 lbs: ½ capsule PO daily. Dogs 40-100 lbs: 1 capsule PO daily. Dogs weighing >100 lbs: 1.5 capsules PO per day.POq24h—🌎 NA
Urethral sphincter hypotonus1-1.5 mg/kg PO two to three times a dayPOq8-12h—🌎 NA
Urethral sphincter hypotonus5-50 mg per dog PO q8h or 1.5 mg/kg PO q8h-12hPOq8-12h—🌎 NA
Retrograde ejaculation3-4 mg/kg PO twice dailyPOq12h—🌎 NA
  • Urethral sphincter hypotonus: Using the time-release 75 mg capsules
  • Urethral sphincter hypotonus: Controls 74-92% of dogs with primary sphincter mechanism incontinence. Over half of dogs not responding to regular PPA will respond to sustained-release PPA.
  • Retrograde ejaculation: May be tried

猫

適応用量経路頻度期間地域
Urethral sphincter hypotonus12.5 mg PO q8hPOq8h—🌎 NA
Urethral sphincter hypotonus1-1.5 mg/kg PO q8hPOq8h—🌎 NA
Urethral sphincter hypotonus1.1 -2.2 mg/kg PO two to three times dailyPOq8-12h—🌎 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

フェニルプロパノールアミン（PPA）は非選択的交感神経刺激アミンであり、獣医療では主に避妊手術後の雌犬に見られる​尿道括約筋機能不全（USMI）​に関連する​尿失禁​の管理に使用されます。

歴史的には鼻閉改善薬として使用されてきましたが、獣医療における主な適応は、膀胱頸部および近位尿道の平滑筋緊張を高める作用に基づいています。

​臨床上のポイント：​

  • PPAは犬の後天性尿失禁に対して非常に有効であり、成功率はしばしば75〜85％を超えます。
  • 交感神経刺激薬であるため、全身性の作動性作用、特に高血圧や行動の変化（落ち着きのなさ、不安）を引き起こす可能性があります。
  • 米国では、メタンフェタミン合成の前駆物質として使用される可能性があるため、リスト1化学物質に分類されており、購入に特定の制限が課される場合があります。

作用機序

Phenylpropanolamine acts primarily as an indirect-acting sympathomimetic, though it may have some direct receptor agonist activity.

  • ​Mechanism:​ It stimulates the release of endogenous norepinephrine from presynaptic nerve terminals.
  • ​Pathway:​ Released norepinephrine binds to alpha-1 adrenergic receptors located in the smooth muscle of the internal urethral sphincter and bladder neck → increased sphincter tone → prevention of urine leakage.
  • It also stimulates beta-adrenergic receptors, which can contribute to systemic cardiovascular effects (e.g., increased heart rate and contractility).
  • ​Note:​ Prolonged use or excessive dosing frequency can theoretically deplete norepinephrine from storage sites, leading to tachyphylaxis (decreased response), though this is rarely documented in dogs or cats treated for incontinence.

安全性・警告

禁忌

  • Glaucoma
  • Prostatic hypertrophy
  • Hyperthyroidism
  • Diabetes mellitus
  • Cardiovascular disorders
  • Hypertension
  • Severe renal or hepatic disease

有害事象

  • Restlessness
  • Anxiety
  • Irritability
  • Urine retention
  • Tachycardia
  • Hypertension
  • Anorexia
  • Rare reports of 'stroke' in dogs
  • Panting

注意事項

Use with caution in patients with glaucoma, prostatic hypertrophy, hyperthyroidism, diabetes mellitus, cardiovascular disorders, or hypertension. May cause decreased ovum implantation, though clinical experience has not demonstrated untoward effects during pregnancy.

医薬品相互作用

HalothaneMajor

Increased risk of arrhythmias. Propranolol may be administered should these occur.

Monoamine Oxidase (MAO) Inhibitors (e.g., amitraz, selegiline)

Should not be given within two weeks of receiving MAOIs due to risk of severe hypertension and toxicity.

NSAIDs (including aspirin)

Increased chance of hypertension if given concomitantly.

Reserpine

Increased chance of hypertension if given concomitantly.

Other Sympathomimetic Agents (e.g., ephedrine)

Should not be administered together as increased toxicity may result.

Tricyclic Antidepressants (e.g., clomipramine, amitriptyline)

Increased chance of hypertension if given concomitantly.

NSAIDsModerate

Increased risk of hypertension

Monoamine Oxidase Inhibitors (MAOIs)Major

Risk of severe hypertensive crisis

Tricyclic AntidepressantsMajor

Increased sympathomimetic effects and risk of hypertension

監視

  • Clinical effectiveness (reduction in urine leakage)
  • Adverse effects (restlessness, irritability, anorexia)
  • Blood pressure
  • Clinical response (reduction in urinary incontinence)
  • Heart rate and rhythm
  • Behavioral changes (restlessness, pacing)

薬物動態

半減期

猫Unknown犬Approximately 3 to 4 hours

吸収

In humans, readily absorbed after oral administration. Onset of action is about 15-30 minutes with a duration of effect lasting approximately 3 hours (regular capsules/tablets).

分布

Reportedly distributed into various tissues and fluids, including the CNS. Unknown if it crosses the placenta or enters milk.

代謝

Partially metabolized to an active metabolite.

消失

80-90% is excreted unchanged in the urine within 24 hours of dosing.

過剰投与

Clinical signs of overdosage may consist of an exacerbation of adverse effects (restlessness, anxiety).

​Severe Overdose Signs:​

  • ​Cardiovascular:​ Hypertension to rebound hypotension, bradycardias to tachycardias, and cardiovascular collapse.
  • ​CNS:​ Stimulation progressing to coma.
  • Case report: A dog ingesting 48 mg/kg developed ventricular tachycardia and myocardial necrosis (resolved within 6 months).

​Treatment:​

  • If recent, empty the stomach using usual precautions and administer charcoal and a cathartic.
  • Treat clinical signs supportively.

  • ​WARNING:​ Do NOT use propranolol to treat hypertension in bradycardic patients. Do NOT use atropine to treat bradycardia.

  • Hypertension may be managed with a phenothiazine (e.g., acepromazine at very low doses such as 0.02 mg/kg IV or IM). If unsuccessful, consider a CRI of nitroprusside.
  • Contact an animal poison control center for further guidance.

製品

製剤

  • Chewable tablets
  • Timed-release capsules
  • Oral solution
  • 40 mg/ml syrup
  • 15 mg tablet
  • 50 mg tablet

動物用医薬品

  • Phenylpropanolamine Chewable Tablets: 25 mg, 50 mg, & 75 mg (Proin, Propalin, Uriflex-PT, Uricon)
  • Phenylpropanolamine Timed-Release Capsules: 75 mg (Cystolamine)
  • Phenylpropanolamine oral solution: 25 mg/mL in 60 mL bottles (Proin Drops); 50 mg/mL in 30 mL and 100 mL bottles
  • Propalin 40 mg/ml syrup
  • Urilin 40 mg/ml syrup
  • Proin 15 mg tablets
  • Proin 50 mg tablets

ヒト用医薬品

  • Removed from the US market due to potential adverse effects in humans.

規制ステータス

European Union✓ 承認済み処方箋医薬品EMA
🐕 Dogs

Classified as POM-V (Prescription Only Medicine - Veterinary).

United Kingdom✓ 承認済み処方箋医薬品VMD
🐕 Dogs

Classified as POM-V.

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

保管・安定性

Store phenylpropanolamine products at room temperature in light-resistant, tight containers.

飼主向け情報

​重要​：この薬が効果を発揮するためには、獣医師の指示通りに正確に投与する必要があります。投与を忘れると効果が失われ、尿漏れが再発します。

  • 薬の十分な効果が現れるまでに数日かかる場合があります。
  • この薬は尿失禁を管理するものであり、完治させるものではありません。通常、長期的な投与が必要です。
  • ​獣医師への連絡の目安​：ペットに持続的な行動の変化（過度なパンティング、落ち着きのなさ、うろうろする、怒りっぽくなるなど）が見られる場合、食欲がなくなった場合、または尿失禁が続くか悪化する場合は、獣医師に連絡してください。

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。