ドパミン
Dopamine
3-hydroxytyramine hydrochloride
別名: Intropin · ASL-279 · dopamini hydrochloridum · 3-hydroxytyramine hydrochloride
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
これは持続点滴（CRI）の速度依存用量です。単純な体重換算ではなく、注入速度を計算してください。
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 |
|---|---|---|---|---|---|
| Vasodilatory shock if fluid resuscitation and dobutamine is not successful | 2.5-10 micrograms/kg/min | IV | CRI | Titrated to effect | 🌎 NA |
| Adjunctive therapy for acute heart failure | 1-10 micrograms/kg/min | IV | CRI | Titrated to effect | 🌎 NA |
| Treatment of severe hypotension/shock | 1-3 micrograms/kg/minute CRI; higher dosages of 3-10 micrograms/kg/min CRI are indicated if greater cardiotonic and BP support are indicated | IV | CRI | Titrated to effect | 🌎 NA |
| Treatment of severe hypotension/shock after fluid correction and if dobutamine does not give desired effect | 1-10 micrograms/kg/min | IV | CRI | Titrated to effect | 🌎 NA |
| Adjunctive therapy for oliguric renal failure | 1-3 micrograms/kg/min | IV | CRI | Until nonoliguric state achieved | 🌎 NA |
- Vasodilatory shock if fluid resuscitation and dobutamine is not successful: If not successful may try adding norepinephrine.
- Adjunctive therapy for acute heart failure: Initially, a dose of 2 micrograms/kg/min is usually used and titrated upward to desired clinical effect. Doses higher than 10 may increase peripheral vascular resistance and heart rate.
- Treatment of severe hypotension/shock: Not a substitute for adequate volume replacement therapy.
- Adjunctive therapy for oliguric renal failure: Used with diuretics (furosemide). Note: Many now believe that dopamine is not indicated for treating acute renal failure.
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Vasodilatory shock if fluid resuscitation and dobutamine is not successful | 2.5-10 micrograms/kg/min | IV | CRI | Titrated to effect | 🌎 NA |
| Treatment of severe hypotension/shock | 1-3 micrograms/kg/minute CRI; higher dosages of 3-10 micrograms/kg/min CRI are indicated if greater cardiotonic and BP support are indicated | IV | CRI | Titrated to effect | 🌎 NA |
| Treatment of severe hypotension/shock after fluid correction and if dobutamine does not give desired effect | 1-10 micrograms/kg/min | IV | CRI | Titrated to effect | 🌎 NA |
- Vasodilatory shock if fluid resuscitation and dobutamine is not successful: If not successful may try adding norepinephrine.
- Treatment of severe hypotension/shock: Not a substitute for adequate volume replacement therapy.
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
ドパミンは内因性のカテコールアミンであり、ノルアドレナリンの直接の代謝前駆体です。獣医療の集中治療において、主に適切な輸液蘇生を行った後の血行動態の不安定性（特に低血圧性ショックや急性心不全）を管理するため、持続静脈内投与（CRI）として使用されます。
臨床上のハイライト
- 用量依存性の効果: ドパミンの受容体親和性は輸注速度によって劇的に変化し、ドパミン作動性（血管拡張）からβ1（強心作用）、そしてα1（昇圧作用）へと移行します。
- 腎用量に関する議論: 歴史的に、「低用量」ドパミンは乏尿性急性腎障害における利尿を促進するために使用されてきました。しかし現代のエビデンスでは、糸球体濾過量（GFR）を有意に改善しないことが示されており、犬での使用は証明されていないか議論の余地があり、猫では有害となる可能性があります。
- 厳格な投与規則: 専用の静脈ラインとシリンジポンプまたは輸液ポンプを使用して投与する必要があります。血管外漏出は重篤な組織壊死を引き起こします。
作用機序
Dopamine acts directly on dopaminergic, β1-adrenergic, and α1-adrenergic receptors, and indirectly by stimulating the release of endogenous norepinephrine from sympathetic nerve terminals. Its effects are highly dose-dependent:
- Low Dose (0.5–2 µg/kg/min): Primarily stimulates D1 and D2 dopaminergic receptors → vasodilation of renal, mesenteric, coronary, and intracerebral vascular beds. Increases renal blood flow and urine output, but does not appreciably increase GFR.
- Medium Dose (2–10 µg/kg/min): Stimulates β1-adrenergic receptors in the myocardium → increases intracellular cAMP → positive inotropic (increased contractility) and mild chronotropic (increased heart rate) effects. Improves cardiac output and organ perfusion.
- High Dose (>10–12 µg/kg/min): Overrides dopaminergic effects and strongly stimulates α1-adrenergic receptors in the vasculature → profound vasoconstriction → increases systemic vascular resistance (SVR) and blood pressure. Renal and peripheral blood flows are decreased at these rates.
安全性・警告
禁忌
- Pheochromocytoma
- Ventricular fibrillation
- Uncorrected tachyarrhythmias
- Uncorrected hypovolemia (must replace fluids first)
有害事象
- Nausea and vomiting
- Ectopic beats (arrhythmias)
- Tachycardia
- Palpitations
- Hypotension (at low doses) or Hypertension (at high doses)
- Dyspnea
- Vasoconstriction (reduced peripheral circulation)
- Severe tissue necrosis and sloughing (if extravasated)
注意事項
Critical Warnings
- Extravasation Risk: Extravasation can cause severe ischemic tissue necrosis and sloughing. Monitor IV sites continuously. If extravasation occurs, infiltrate the ischemic area with 5-10 mg phentolamine diluted in 10-15 mL of normal saline using a fine needle with multiple subcutaneous injections.
- Hypovolemia: Dopamine is not a substitute for adequate fluid, electrolyte, or blood product replacement. Volume deficits must be corrected prior to use.
- Cardiovascular Disease: Use with extreme caution in patients with ischemic heart disease or occlusive vascular disease. Discontinue or reduce dose if arrhythmias (e.g., PVCs) occur or if signs of reduced peripheral circulation develop.
- Feline Renal Failure: Cats are unlikely to benefit from low-dose dopamine for oliguric renal failure, and it may be detrimental.
医薬品相互作用
May antagonize the vasoconstrictive properties of high-dose dopamine.
May result in increased incidences of ventricular arrhythmias.
May potentiate adverse cardiovascular effects.
May antagonize the cardiac (inotropic/chronotropic) effects of dopamine.
May potentiate urine production effects of low-dose dopamine.
Can significantly prolong and enhance the effects of dopamine.
May cause severe hypertension when used concurrently.
May antagonize the renal and mesenteric vasodilatation effects of dopamine.
Concurrent use may cause severe hypertension.
監視
- Continuous electrocardiogram (ECG) for cardiac rate and rhythm
- Direct or indirect blood pressure
- Urine output/flow
- IV catheter site (frequent checks for patency and signs of extravasation)
薬物動態
半減期
吸収
Not administered orally as it is rapidly metabolized in the GI tract. After IV administration, onset of action is usually within 5 minutes.
分布
Widely distributed in the body, but does not cross the blood-brain barrier in appreciable quantities. Placental transfer is unknown.
代謝
Metabolized in the kidney, liver, and plasma by monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) to inactive compounds. Up to 25% is metabolized to norepinephrine in adrenergic nerve terminals.
消失
Rapidly cleared; effects persist for less than 10 minutes after the infusion is stopped.
過剰投与
Accidental overdosage is primarily manifested by excessive blood pressure elevation (severe hypertension) and arrhythmias.
- Treatment: Because dopamine's half-life is extremely short (~2 minutes), treatment usually consists only of temporarily discontinuing the IV infusion or reducing the rate until parameters normalize.
- If the patient's condition fails to stabilize rapidly after discontinuation, the alpha-adrenergic antagonist phentolamine may be administered.
製品
製剤
- Concentrated solution for injection (40 mg/mL, 80 mg/mL, 160 mg/mL)
- Premixed injection solution in Dextrose 5% (0.8 mg/mL, 1.6 mg/mL, 3.2 mg/mL)
ヒト用医薬品
- Dopamine HCl for Concentrated Solution for Injection: 40 mg/mL, 80 mg/mL and 160 mg/mL in 5 mL & 10 mL vials
- Dopamine HCl in Dextrose 5% Injection Solution: 200 mg/250 mL (0.8 mg/mL); 400 mg/500 mL (0.8 mg/mL); 400 mg/250 mL (1.6 mg/mL); 800 mg/500 mL (1.6 mg/mL); & 800 mg/250 mL (3.2 mg/mL) in premixed containers
規制ステータス
規制データなし: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Protect from light. Store at room temperature (15-30°C). Solutions that are pink, yellow, brown, or purple indicate decomposition and must be discarded. After dilution in compatible IV fluids (e.g., normal saline, D5W, LRS), it is stable for at least 24 hours at room temperature, though it is recommended to dilute just prior to use. Most stable at pH < 5; oxidized at alkaline pH.
飼主向け情報
ドパミンは、通常は集中治療室（ICU）などの病院環境でのみ使用される集中治療薬です。
- 目的: 重度のショックや心不全などの生命を脅かす状態において、ペットの血圧、心機能、臓器への血流をサポートするために使用されます。
- 投与方法: 正確な投与量を確保するため、専用のポンプを使用して持続的な静脈内（IV）点滴として投与されます。
- モニタリング: この薬を使用している間、ペットは獣医療チームによって、継続的な心拍数、心電図、血圧のチェックなど、厳密に監視されます。
- 安全性: この薬が血管外に漏れると組織に損傷を与える可能性があるため、獣医療チームは静脈カテーテルを頻繁にチェックします。
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