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肼屈嗪

Hydralazine

Hydralazine HCl

血管擴張劑POIV狗貓馬

別名: Alphapress · Bionobal · Cesoline · Hydrapres · Hyperex · Hyperphen · Ipolina · Nepresol · Novo-Hylazin · Nu-Hydral · Rolazine · Slow-Apresoline · Supres · apressinum · hydralazini · hydrallazine · Hydralazine hydrochloride · Hidralazina

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

1 mg/kg (starting dose, titrate up to 3 mg/kg if needed)PO· q12h
— 🐕

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
Adjunctive therapy in treatment of heart failure (not receiving ACE inhibitors)1 mg/kg (starting dose, titrate up to 3 mg/kg if needed)POq12h—🌎 NA
Acute, fulminant heart failure due to severe mitral regurgitation (not receiving ACE inhibitors)2 mg/kgPOOnce—🌎 NA
Adjunctive therapy in treatment of heart failure (receiving ACE inhibitors)0.5 mg/kg (starting dose, increase in 0.5 mg/kg increments to max 3 mg/kg)POq12h—🌎 NA
Short-term treatment of CHF secondary to valve diseaseInitial dose of 1 mg/kg PO (additional 0.5-1 mg/kg can be administered to max cumulative 3 mg/kg)POq12hShort-term🌎 NA
Treatment of systemic hypertension (Fifth step drug)0.5 mg/kgPOtwice daily—🌎 NA
Congestive heart failure / Systemic hypertension0.5-3 mg/kgPOq8-12hLong-term🌍 EU
  • Adjunctive therapy in treatment of heart failure (not receiving ACE inhibitors): Effective dose is 0.5-3 mg/kg PO q12h. Titrate upwards carefully. If BP monitored, can titrate more rapidly in 1-2 hour intervals.
  • Acute, fulminant heart failure due to severe mitral regurgitation (not receiving ACE inhibitors): Given along with IV furosemide. May cause hypotension, but benefits outweigh risks.
  • Adjunctive therapy in treatment of heart failure (receiving ACE inhibitors): Give with extreme caution as severe hypotension may occur. Blood pressure monitoring required.
  • Short-term treatment of CHF secondary to valve disease: Goal MAP is 60-80 mmHg. Once desired BP achieved, administer PO q12h.
  • Treatment of systemic hypertension (Fifth step drug): Added if systolic BP > 160 mmHg after enalapril/benazepril, amlodipine (low then high dose), and spironolactone.
  • Congestive heart failure / Systemic hypertension: Start at low dose (0.5-1 mg/kg q12h), monitor blood pressure regularly and increase to 2 mg/kg or even 3 mg/kg q12h if necessary.

貓

適應症劑量途徑頻次療程地區
Adjunctive therapy in treatment of heart failurestart titration at 2.5 mg (total dose) and if necessary, increase up to 10 mgPOq12h—🌎 NA
Treatment of systemic hypertension (Fourth step drug)0.5 mg/kgPOtwice daily—🌎 NA
Systemic hypertension2.5-10 mg/catPOq12hLong-term🌍 EU
  • Adjunctive therapy in treatment of heart failure: Follow similar titration protocols as dogs.
  • Treatment of systemic hypertension (Fourth step drug): Added if systolic BP > 160 mmHg after amlodipine, ACE inhibitor, and spironolactone.
  • Systemic hypertension: Start at low dose and titrate upwards cautiously. Monitor blood pressure regularly.

馬

適應症劑量途徑頻次療程地區
Adjunctive therapy in treatment of heart failure (afterload reducer)0.5 mg/kgIVOnce—🌎 NA
Adjunctive therapy in treatment of heart failure (long-term therapy)0.5-1.5 mg/kgPOq12hLong-term🌎 NA
  • Adjunctive therapy in treatment of heart failure (afterload reducer): ARCI UCGFS Class 3 Drug.

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概覽

肼屈嗪（Hydralazine）是一種強效的​直接作用小動脈血管擴張劑​，主要用於治療全身性高血壓，以及作為小動物充血性心臟衰竭（CHF）的輔助治療（​降低後負荷​）。

  • ​臨床應用​：對於二尖瓣閉鎖不全、大型心室中膈缺損或嚴重主動脈瓣逆流的病例特別有益，因為降低心臟泵血的阻力（後負荷）至關重要。
  • ​難治性心臟衰竭​：當 ACE 抑制劑（如依那普利）無法有效改善二尖瓣閉鎖不全犬隻的臨床症狀時，常會使用此藥。
  • ​合併療法​：通常與利尿劑合併使用，以抵消其引起鈉水滯留的傾向；有時也與 β-受體阻斷劑併用，以減輕反射性心搏過速。
  • ​限制​：若原發性心肌疾病（如擴張性心肌病）是唯一問題且無明顯瓣膜逆流時，使用此藥治療心臟衰竭的效果不佳。

作用機轉

Hydralazine acts as a semicarbazide-sensitive amine oxidase (SSAO) inhibitor, directly relaxing vascular smooth muscle.

  • Mechanism: Alters cellular calcium metabolism in smooth muscle → interferes with calcium movements → prevents the initiation and maintenance of the contractile state.
  • Vascular Selectivity: Exerts a much greater effect on arterioles than on veins. This selective arterial dilation significantly decreases systemic vascular resistance (SVR) and blood pressure.
  • Cardiac Effects: In CHF patients, the reduction in afterload → significantly increases forward cardiac output.
  • Compensatory Responses: In non-CHF hypertensive patients, the sudden drop in blood pressure can trigger baroreceptor-mediated reflex tachycardia and activation of the ​renin-angiotensin-aldosterone system (RAAS)​ → leading to sodium and water retention.

安全性與警告

禁忌症

  • Known hypersensitivity to hydralazine
  • Coronary artery disease
  • Hypovolemia
  • Preexisting hypotension
  • Hypovolaemia
  • Renal impairment
  • Cerebral bleeding

不良反應

  • Weakness and lethargy
  • Syncope (fainting)
  • Reflex tachycardia
  • Sodium and water retention
  • GI distress (vomiting, diarrhea)
  • Increased creatinine levels
  • SLE-like syndrome (documented in humans, theoretical in animals)
  • Lacrimation and conjunctivitis
  • Peripheral neuritis
  • Blood dyscrasias
  • Urinary retention
  • Constipation
  • Severe hypotension
  • Anorexia (especially in cats)
  • Vomiting (especially in cats)

注意事項

Dose Titration: Doses must be titrated upwards carefully to avoid severe, life-threatening hypotension.

  • Renal Disease: Use with caution. Reduced renal blood flow can activate the RAAS and exacerbate renal injury; pretreatment with an ACE inhibitor and spironolactone is often advised.
  • Intracerebral Bleeding: Use with caution due to potential effects on cerebral blood flow.
  • Autoimmune Disease: Use cautiously in patients with preexisting autoimmune diseases, as an SLE-like syndrome has been documented in humans.
  • Pregnancy: FDA Category C (humans); Papich Class B (veterinary). Safe for use if used cautiously, but crosses the placenta. Excreted in milk but generally considered compatible with nursing.

藥物交互作用

ACE-INHIBITORS

May cause additive hypotensive effect; usually used for therapeutic advantage

BETA-BLOCKERS

May cause additive hypotensive effect; usually used for therapeutic advantage

DIAZOXIDE

Potentially could cause profound hypotension

DIURETICSModerate

May cause additive hypotensive effect; usually used for therapeutic advantage

FUROSEMIDE

Hydralazine may increase furosemide's renal effects

MAO INHIBITORS

May cause additive hypotensive effect

SYMPATHOMIMETICS (e.g., epinephrine)

Hydralazine may cause decreased pressor effect and may cause additive tachycardia

ACE inhibitors (e.g., enalapril, benazepril)Major

Enhanced hypotensive effects

AnaestheticsModerate

Enhanced hypotensive effects

Beta-blockers (e.g., propranolol)Moderate

Enhanced hypotensive effects

Calcium-channel blockers (e.g., diltiazem, verapamil)Moderate

Enhanced hypotensive effects

CorticosteroidsMinor

Enhanced hypotensive effects

NSAIDsModerate

Enhanced hypotensive effects

Sympathomimetics (e.g., phenylpropanolamine)Moderate

May cause tachycardia

Adrenaline (Epinephrine)Moderate

Reduced pressor response to adrenaline

監測

  • Baseline thoracic radiographs
  • Mucous membrane color and capillary refill time
  • Serum electrolytes and creatinine
  • Arterial blood pressure (Target MAP 60-80 mmHg for short-term CHF treatment)
  • Venous PO2
  • Occasional CBC (due to possibility of blood dyscrasias)
  • Systemic blood pressure (frequent monitoring during initiation)
  • Heart rate and rhythm
  • Renal function (BUN, Creatinine)
  • Hydration status and body weight (to monitor for fluid retention)

藥物動力學

半衰期

貓Unknown狗2-4 hours

吸收

Rapidly absorbed after oral administration. Onset of action within 1 hour, peak effects at 3-5 hours. High first-pass effect. Food decreases oral bioavailability in dogs by about 63% (though some reports suggest food may enhance tablet bioavailability).

分佈

Widely distributed in body tissues. Approximately 85% bound to plasma proteins in humans. Crosses the placenta and very small amounts are excreted into milk.

代謝

Extensively metabolized in the liver. N-acetylation is a primary enzymatic pathway, which is mostly absent in dogs, leading to increased risks for toxicity.

排除

Approximately 15% is excreted unchanged in the urine. Duration of action in dogs after oral administration is reportedly 11-13 hours.

過量

Clinical Signs: Overdoses are characterized by severe hypotension, reflex tachycardia or other arrhythmias, skin flushing, and myocardial ischemia.

Treatment:

  • Decontamination: Evacuate gastric contents and administer activated charcoal using standard precautions if ingestion was recent and cardiovascular status is stable.
  • Cardiovascular Support: Treat shock using volume expanders. Avoid pressor agents if possible.
  • Pressor Agents: If required to maintain blood pressure, use a minimally arrhythmogenic agent (e.g., phenylephrine or methoxamine).
  • Additional Support: Digitalis agents may be required. Diligently monitor blood pressure and renal function.

可用產品

劑型

  • Oral tablets
  • Injection
  • 25 mg oral tablet
  • 50 mg oral tablet

人用標示

  • Hydralazine HCl Oral Tablets: 10 mg, 25 mg, 50 mg & 100 mg (Apresoline, generic)
  • Hydralazine Injection: 20 mg/mL in 1 mL vials (generic)
  • Apresoline 25 mg tablets
  • Apresoline 50 mg tablets

各地核准狀態

European Union✗ 未核准處方藥EMA

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

United Kingdom✗ 未核准處方藥VMD

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

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

儲存與穩定性

Store tablets in tight, light-resistant containers at room temperature. Store injectable product at room temperature; avoid refrigeration or freezing. When mixed with infusion solutions, a color change may occur over 8-12 hours, which does not necessarily indicate a loss in potency.

飼主須知

肼屈嗪是一種用於降低血壓和減輕寵物心臟工作負擔的藥物，特別適用於患有心臟瓣膜閉鎖不全的寵物。

  • ​嚴格遵從醫囑​：必須完全按照獸醫師的指示給藥，以發揮最大療效並避免血壓危險性下降。
  • ​注意事項​：如果您的寵物變得異常嗜睡、虛弱、抑鬱或暈厥，請立即聯繫您的獸醫師。這些可能是血壓降得太低（低血壓）的跡象。
  • ​副作用​：您可能會注意到輕微的嘔吐或腹瀉。如果這些症狀持續存在，請告知您的獸醫師。
  • ​飲食​：請向獸醫師確認此藥物是否應與食物一起服用，因為食物可能會影響藥物在寵物體內的吸收量。

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