VetSheet

エフェドリン

Ephedrine

Ephedrine sulfate

交感神経刺激性気管支拡張薬 / 昇圧薬POIVIMSCIntranasal犬猫

別名: Enurace · Ephedrine sulphate · Ephedrine hydrochloride · Ephedrini hydrochloridum

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

1-2 mg/kg PO q8-12hPO· q8-12h
— 🐕

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
Treatment of bronchospasm (maintenance therapy)1-2 mg/kg PO q8-12hPOq8-12h—🌎 NA
Treatment of bronchospasm2 mg/kg PO q8-12hPOq8-12h—🌎 NA
Treatment of urinary incontinence5-15 mg (total dose) PO q8hPOq8h—🌎 NA
Treatment of urinary incontinence1.2 mg/kg PO q8h or 5-15 mg (total dose) PO q8hPOq8h—🌎 NA
Treatment of hypotension associated with anesthesia0.03-0.1 mg/kg IV bolusIVOnce, may repeat in 5 minutes—🌎 NA
Treatment of hypotension associated with anesthesia0.1-0.25 mg/kg IV bolusIVOnce—🌎 NA
Treatment of hypotension associated with anesthesia0.1-0.2 mg/kg IV bolusIVOnce15-60 minutes🌎 NA
Treatment of hypotension associated with anesthesia0.15-0.25 mg/kg IV boluses OR CRI at 5-10 micrograms/kg/minuteIVTo effect or CRI—🌎 NA
Hypotension during anaesthesiaDose not specified in monographIV/IMAs needed (effects wane after 2-3 doses)Perioperative🌍 EU
Urinary incontinenceDose not specified in monographPONot specifiedLong-term🌍 EU
  • Treatment of hypotension associated with anesthesia: Dilute 5 mg in 10 mL of saline and give the lower dosage first as sinus tachycardia may accompany the higher dose.
  • Treatment of hypotension associated with anesthesia: For relatively short procedures in ASA I or II patients when hypotension is not responsive to 1 or 2 crystalloid boluses.
  • Treatment of hypotension associated with anesthesia: Dilute into 5 mL of a balanced electrolyte solution or saline and give small increment IV boluses until desirable blood pressure achieved.
  • Hypotension during anaesthesia: Assists in bradycardia. Tachyphylaxis occurs rapidly.
  • Urinary incontinence: Exclude polyuria before treatment. Can be used with phenylpropanolamine.

猫

適応用量経路頻度期間地域
Treatment of bronchospasm (emergency treatment)2-5 mg POPOOnce—🌎 NA
Treatment of urinary incontinence2-4 mg (total dose) PO q8hPOq8h—🌎 NA
Treatment of urinary incontinence2-4 mg/kg PO q6-12h or 2-4 mg (total dose) PO q8hPOq6-12h or q8h—🌎 NA
Treatment of urinary incontinence2-4 mg per cat PO q8-12hPOq8-12h—🌎 NA
Treatment of hypotension associated with anesthesia0.15-0.25 mg/kg IV boluses OR CRI at 5-10 micrograms/kg/minuteIVTo effect or CRI—🌎 NA
Hypotension during anaesthesiaDose not specified in monographIV/IMAs neededPerioperative🌍 EU
Nasal congestion (cat 'flu')Dose not specified in monographtopicalNot specifiedShort-term🌍 EU
  • Treatment of hypotension associated with anesthesia: Dilute into 5 mL of a balanced electrolyte solution or saline and give small increment IV boluses until desirable blood pressure achieved.
  • Hypotension during anaesthesia: Use with caution.
  • Nasal congestion (cat 'flu'): Proposed for treatment of nasal congestion; may be of some benefit.

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

エフェドリンは非カテコールアミン系の交感神経刺激アミンです。獣医療では主に犬および猫の​尿道括約筋機能不全（USMI）​の管理に使用されますが、中枢神経系の副作用が少ないフェニルプロパノールアミン（PPA）が好まれることが多いです。

さらに、麻酔誘発性の低血圧に対処するための注射用​昇圧薬​として、また呼吸器疾患に対する​気管支拡張薬​としても機能します。

​臨床のポイント:​ エフェドリンは他の多くの交感神経刺激薬よりも血液脳関門を通過しやすいため、軽度から中等度の中枢神経刺激を引き起こす可能性があり、一部の患者では落ち着きのなさや興奮として現れます。

作用機序

Ephedrine is a mixed-acting sympathomimetic.

  • ​Indirect Action (Primary):​ It enters the sympathetic nerve terminal and promotes the release of stored norepinephrine into the synaptic cleft.
  • ​Direct Action (Secondary):​ It directly stimulates ​α- and β-adrenergic receptors​.

​Key Pathways:​

  • ​α1-receptors​ → Smooth muscle contraction → Increased internal urethral sphincter tone (improving continence) and peripheral vasoconstriction (increasing blood pressure).
  • ​β1-receptors​ → Positive inotropic and chronotropic effects on the heart → Increased cardiac output.
  • ​β2-receptors​ → Smooth muscle relaxation → Bronchodilation.

​Note:​ Because it relies heavily on endogenous norepinephrine stores, repeated frequent dosing can deplete these stores, leading to tachyphylaxis (diminished response over time).

安全性・警告

禁忌

  • Severe cardiovascular disease
  • Cardiac arrhythmias
  • Pregnancy
  • Lactation
  • Glaucoma

有害事象

  • Irritability
  • Tachycardia
  • Hypertension
  • Anorexia
  • Tachyphylaxis (decreased response to subsequent doses)
  • Panting
  • Mydriasis (dilated pupils)
  • CNS stimulation (restlessness, agitation)
  • Atrial fibrillation
  • Vasoconstriction
  • Reduction of intestinal wall motility and tone

注意事項

Use with caution in patients with glaucoma, prostatic hypertrophy, hyperthyroidism, diabetes mellitus, cardiovascular disorders, or hypertension.

When administered IV, the administration rate should be carefully controlled (in humans, not to exceed 10 mg/minute; scale appropriately for veterinary patients).

​Pregnancy/Nursing:​ FDA Category C. Excreted in milk and may have deleterious effects on nursing animals. Consider milk replacer if use is absolutely necessary in a nursing dam.

医薬品相互作用

Acepromazine (and other phenothiazines)

Phenothiazines block alpha-adrenergic receptors; concomitant use can lead to unopposed beta-activity causing vasodilation and increased cardiac rate.

Alpha-blockers (e.g., phentolamine, prazosin)

May negate the therapeutic effects of ephedrine.

General Anesthetics (cyclopropane, halogenated hydrocarbons)

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

Beta-blockers

Concomitant use may diminish the effects of both drugs.

DigoxinMajor

Increased risk of arrhythmias if used concurrently.

Monoamine Oxidase Inhibitors (including amitraz)

Should not be given within two weeks of receiving MAOIs; severe hypertension and hyperpyrexia are possible.

Other Sympathomimetic Agents (e.g., phenylpropanolamine)

Should not be administered together as increased toxicity may result.

Reserpine

May reverse the pressor effects of ephedrine.

TheophyllineModerate

May increase the risk for theophylline toxicity.

Tricyclic Antidepressants

May decrease the pressor effects of ephedrine.

Urinary Alkalinizers (e.g., sodium bicarbonate, citrates, carbonic anhydrase inhibitors)

May reduce urinary excretion of ephedrine and prolong its duration of activity, potentially requiring dosage adjustments.

Other sympathomimeticsModerate

Synergistic effects, increasing the risk of adverse cardiovascular and CNS stimulation.

Volatile anaestheticsMajor

Enhances the sensitivity of the myocardium to the arrhythmogenic effects of ephedrine.

Cardiac glycosides (e.g., digoxin)Major

Concomitant use can cause severe cardiac arrhythmias.

Tricyclic antidepressants (e.g., amitriptyline)Major

Concomitant use can cause severe cardiac arrhythmias.

MAO inhibitors (e.g., selegiline)Major

May cause severe hypertension when given concurrently.

AmitriptylineMajor

Concomitant use with tricyclic antidepressants can cause arrhythmias.

SelegilineMajor

Concomitant use with MAO inhibitors may cause severe hypertension.

PhenylpropanolamineModerate

Can be used in conjunction for urinary incontinence, but increases sympathetic load.

監視

  • Clinical effectiveness (resolution of incontinence, improved blood pressure, or bronchodilation)
  • Behavioral changes (restlessness, irritability)
  • Heart rate and rhythm (ECG during anaesthesia)
  • Resolution of urinary incontinence
  • Signs of CNS stimulation or excessive panting

薬物動態

吸収

Rapidly absorbed after oral or parenteral administration.

分布

Thought to cross both the blood-brain barrier and the placenta.

代謝

Metabolized in the liver.

消失

Excreted unchanged in the urine. Urine pH may significantly alter excretion characteristics.

過剰投与

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

In a very large overdose, severe cardiovascular signs (hypertension leading to rebound hypotension, bradycardias to tachycardias, and cardiovascular collapse) or CNS effects (ranging from severe stimulation to coma) can be seen.

​Treatment:​

  • If the overdose was recent, empty the stomach using usual precautions.
  • Administer activated charcoal and a cathartic.
  • Treat clinical signs supportively as they occur.

製品

製剤

  • Capsules
  • 10 mg tablet
  • 15 mg tablet
  • 30 mg tablet
  • 50 mg tablet
  • 3 mg/ml solution for injection
  • 30 mg/ml solution for injection
  • 0.5% nasal drops
  • 1% nasal drops

動物用医薬品

  • Enurace 10 mg, 15 mg, 30 mg, 50 mg tablets

ヒト用医薬品

  • Ephedrine Sulfate Capsules: 25 mg
  • Ephedrine Sulfate Injection: 50 mg/mL in 1 mL single-dose vials & preservative free in 1 mL single-dose amps
  • Ephedrine hydrochloride 3 mg/ml, 30 mg/ml solutions for injection
  • Ephedrine 0.5%, 1% nasal drops

規制ステータス

European Union✓ 承認済み処方箋医薬品EMA
🐕 Dogs

POM-V classification in the UK/EU.

United Kingdom✓ 承認済み処方箋医薬品VMD
🐕 Dogs

POM-V, POM.

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

保管・安定性

Store ephedrine sulfate products in tight, light-resistant containers at room temperature unless otherwise directed. When used parenterally, ephedrine sulfate is usually administered directly and not diluted.

飼主向け情報

  • ​継続が鍵です:​ 尿失禁に対して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、尿漏れが再発する可能性があります。
  • ​忍耐:​ 薬の完全な効果が現れるまでに数日かかる場合があります。
  • ​副作用:​ この薬は刺激剤のように作用するため、ペットが「そわそわ」する可能性があります。ペットに持続的な行動の変化（落ち着きのなさ、イライラ、うろうろする）が見られる場合、または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。
  • ​タイミング:​ 睡眠の妨げにならないよう、特別な指示がない限り、その日の最後の投与を就寝直前に行うのは避けてください。
  • ​食欲:​ ペットの食欲が一時的に低下することに気づくかもしれません。

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