ニトロプルシドナトリウム
Nitroprusside Sodium
disodium (OC-6-22)pentakis(cyano-C)nitrosylferrate dihydrate
別名: Nitropress · natrii nitroprussias · sodium nitroferricyanide dihydrate · sodium nitroprussiate
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
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 |
|---|---|---|---|---|---|
| Hypertensive crisis (systolic arterial BP >200 mm Hg) | Initiate dose at 1-2 micrograms/kg/minute; increase dosage incrementally every 3-5 minutes until a predetermined target BP is attained. Reduce BP 25% over 4-hour period to allow readaptation of cerebral blood vessels. | IV | CRI | Titrate to effect | 🌎 NA |
| Adjunctive treatment of heart failure (cardiogenic shock; fulminant pulmonary edema) | Initiate dose at 1-2 micrograms/kg/minute; increase dosage incrementally every 3-5 minutes. Goal is to decrease or maintain mean arterial pressure to support vital organ functions-approx. 70 mmHg. | IV | CRI | Titrate to effect | 🌎 NA |
| Adjunctive treatment of heart failure | 0.5-10 micrograms/kg/min IV at a low fluid rate (2 mL/kg/hr) using D5W or other low sodium fluid. Usually start at 2 micrograms/kg/min and increase the base concentration by 1 microgram/kg every 20-30 minutes until there is an improvement in respiratory effort and thoracic auscultation. | IV | CRI | Maintain effective dose for 48 hours | 🌎 NA |
| Catastrophic pulmonary edema | As a CRI initiated at 1 microgram/kg/min and carefully titrated to effect by increasing by 1 microgram/kg/min increments every 15 minutes as long as BP remains stable and until perfusion and pulmonary function improves (usually requires between 2-5 micrograms/kg/min with the upper limit being 8-10 micrograms/kg/min). | IV | CRI | Maintain most effective dose for 12-15 hours | 🌎 NA |
- Adjunctive treatment of heart failure (cardiogenic shock; fulminant pulmonary edema): Concurrent use of dobutamine (5-10 micrograms/kg/min) often indicated.
- Adjunctive treatment of heart failure: Monitor blood pressure; cyanide poisoning can occur if infusion lasts more than 3 days. Taper drip as enalapril is initiated.
- Catastrophic pulmonary edema: Systolic BP must remain >90 mm Hg. Wean nitroprusside over 6 hours first, then dobutamine over 6 hours.
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Hypertensive crisis (systolic arterial BP >200 mm Hg) | Initiate dose at 0.5 micrograms/kg/minute; increase dosage incrementally every 3-5 minutes until a predetermined target BP is attained. Reduce BP 25% over 4-hour period to allow readaptation of cerebral blood vessels. | IV | CRI | Titrate to effect | 🌎 NA |
| Adjunctive treatment of heart failure (cardiogenic shock; fulminant pulmonary edema) | Initiate dose at 0.5 micrograms/kg/minute; increase dosage incrementally every 3-5 minutes. Goal to decrease or maintain mean arterial pressure to support vital organ functions-approx. 70 mmHg. | IV | CRI | Titrate to effect | 🌎 NA |
| Adjunctive treatment of heart failure | Initiate dose at 0.5 micrograms/kg/minute constant rate infusion and increase by 0.5-1 microgram/minute every 5 minutes to desired systolic pressure (90-100 mmHg). | IV | CRI | Titrate to effect | 🌎 NA |
| Catastrophic pulmonary edema | As a CRI initiated at 1 microgram/kg/min and carefully titrated to effect by increasing by 1 microgram/kg/min increments every 15 minutes as long as BP remains stable and until perfusion and pulmonary function improves (cats usually requires between 1-2 micrograms/kg/min with the upper limit being 2 micrograms/kg/min). | IV | CRI | Maintain most effective dose for 12-15 hours | 🌎 NA |
- Adjunctive treatment of heart failure (cardiogenic shock; fulminant pulmonary edema): Concurrent use of dobutamine (1-5 micrograms/kg/min) often indicated.
- Adjunctive treatment of heart failure: Cats are more sensitive to oxidative damage; keep total dosages to a minimum. Use dedicated line; never flush.
- Catastrophic pulmonary edema: Systolic BP must remain >90 mm Hg. Wean nitroprusside over 6 hours first, then dobutamine over 6 hours.
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
ニトロプルシドナトリウムは、集中治療室（ICU）環境で専ら使用される、非常に強力で超短時間作用型の混合性血管拡張薬です。
主な臨床的特徴：
- 主な適応症：高血圧クリーゼ、重度の僧帽弁閉鎖不全症に続発する急性心不全、および難治性うっ血性心不全（CHF）の管理。
- 血行動態への影響：動脈および静脈の平滑筋を弛緩させることにより、前負荷と後負荷を急速に低下させます。
- 臨床上のポイント：強力な降圧作用と超短半減期を持つため、持続的な直接動脈圧モニタリングを伴う定速点滴（CRI）として投与する必要があります。
- 毒性のリスク：長期使用（48〜72時間以上）または高用量投与は、特に腎機能または肝機能障害のある患者において、有毒な代謝物（シアン化物およびチオシアン酸塩）の蓄積を引き起こす可能性があります。
作用機序
Nitroprusside acts as a nitric oxide (NO) donor.
- Once in the bloodstream, it interacts with tissue sulfhydryl groups to release NO.
- NO activates the enzyme soluble guanylate cyclase in vascular smooth muscle cells.
- This leads to an increase in intracellular cyclic guanosine monophosphate (cGMP).
- Elevated cGMP activates protein kinase G, which reduces intracellular calcium concentrations → vascular smooth muscle relaxation.
This mechanism causes direct peripheral vasodilation of both arterioles and venules (independent of autonomic innervation), resulting in:
- Lowered blood pressure
- Significant reduction in total peripheral resistance (afterload)
- Reduced left ventricular end-diastolic pressure (preload)
- Mild decrease in cardiac output (though in severe heart failure, CO may actually increase due to afterload reduction)
- Reflex tachycardia (increase in heart rate)
安全性・警告
禁忌
- Compensatory hypertension (e.g., AV shunts, coarctation of the aorta, Cushing's reflex)
- Inadequate cerebral circulation
- Emergency surgery in patients near death
有害事象
- Profound hypotension
- Nausea
- Retching
- Restlessness
- Apprehension
- Muscle twitching
- Dizziness
- Infusion site irritation (avoid extravasation)
- Thiocyanate and cyanide toxicity (with prolonged use)
注意事項
CRITICAL WARNING: Must only be used in an ICU setting with continuous blood pressure monitoring.
- Organ Impairment: Use with extreme caution in patients with hepatic insufficiency, severe renal impairment, hyponatremia, or hypothyroidism due to increased risk of thiocyanate/cyanide toxicity.
- Surgical Use: When used for controlled hypotension during surgery, patients have less tolerance to hypovolemia, anemia, or blood loss.
- Geriatrics: Older patients may be more sensitive to hypotensive effects.
- Pregnancy: FDA Category C. Animal studies show adverse fetal effects. Use cautiously as a last resort when benefits clearly outweigh risks. Unknown if excreted in milk.
医薬品相互作用
May enhance the hypotensive effects of nitroprusside.
Synergistic effects (increased cardiac output and reduced wedge pressure) may result; often used together beneficially in severe heart failure.
Patients may be more sensitive to the hypotensive effects of nitroprusside.
監視
- Blood pressure (constant, direct arterial monitoring preferred)
- Acid/base balance (to detect early metabolic acidosis/cyanide toxicity)
- Electrolytes (especially Na+)
- Respiratory effort and thoracic auscultation
- Serum thiocyanate levels (if on prolonged therapy or concurrent renal dysfunction)
薬物動態
半減期
吸収
Immediate onset of action following IV infusion. Blood pressure returns to pretreatment levels within 1-10 minutes following cessation of therapy.
分布
Rapidly distributed in the bloodstream.
代謝
Metabolized non-enzymatically in the blood and tissues to cyanogen (cyanide radical). Cyanogen is then converted in the liver to thiocyanate.
消失
Eliminated in the urine, feces, and exhaled air.
過剰投与
Acute Overdosage: Manifests as profound hypotension.
- Treatment: Reduce or stop the infusion and administer IV fluids. Blood pressure will typically recover within 1-10 minutes. Monitor BP constantly.
Toxicity (Cyanide/Thiocyanate): Excessive doses, prolonged therapy (>3 days), depleted hepatic thiosulfate, or severe hepatic/renal insufficiency may lead to cyanogen or thiocyanate toxicity.
- Signs: Metabolic acidosis (early sign of cyanogen toxicity), tolerance to therapy, delirium (thiocyanate toxicity in dogs).
- Monitoring: Monitor acid/base status. Serum thiocyanate levels >100 mcg/mL are considered toxic.
- Treatment: Hydroxocobalamin (Vitamin B12a) may prevent or treat cyanogen toxicity. Contact an animal poison control center for specific antidotal protocols if suspected.
製品
製剤
- Powder for injection
ヒト用医薬品
- Nitroprusside Sodium Powder for Injection: 50 mg/vial in 2 mL and 5 mL vials (Nitropress)
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
Store powder protected from light and moisture at room temperature (15-30°C). Reconstitute ONLY with 5% Dextrose in Water (D5W). Immediately protect the reconstituted solution from light using aluminum foil or an opaque cover. Stable for 24 hours after reconstitution. Discard any solution that turns blue, dark red, or green (indicates degradation and loss of potency). Do not add any other medications to the IV line running nitroprusside.
飼主向け情報
集中治療用薬
- この薬は、集中治療室（ICU）環境において獣医療の専門家によってのみ使用されるべきものです。
- 専用の輸液ポンプによる正確な静脈内投与と、ペットの血圧の分単位での継続的なモニタリングが必要です。
- 重度の心不全や危険な高血圧クリーゼに陥っているペットを急速に安定させるために使用される救命薬です。
- 非常に強力な薬であるため、獣医療チームはペットの低血圧の兆候や薬の分解産物による副作用がないか注意深く監視します。
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。