プロタミン硫酸塩
Protamine Sulfate
Protamini sulfas
別名: Prosulf · protamine sulphate · protamini sulfas · sulfato de protamina · Protamine sulfate
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 |
|---|---|---|---|---|---|
| Heparin overdosage | 1-1.5 mg protamine sulfate to antagonize each mg (100 units) of heparin via slow IV injection. Reduce dose as time increases between heparin dose and start of treatment (after 30 minutes give only 0.5 mg). | IV | Single dose | — | 🌎 NA |
| Heparin overdosage | Administer 1 mg protamine for each 100 Units of heparin to be inactivated. Decrease protamine dose by ½ for every 30 minutes that have lapsed since heparin was administered | IV | Single dose | — | 🌎 NA |
- Heparin overdosage: Give slowly.
- Heparin overdosage: May be ineffective if heparin was given deep SC. Do not give faster than 50 mg over 10 minutes.
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Heparin overdosage | 1-1.5 mg protamine sulfate to antagonize each mg (100 units) of heparin via slow IV injection. Reduce dose as time increases between heparin dose and start of treatment (after 30 minutes give only 0.5 mg). | IV | Single dose | — | 🌎 NA |
| Heparin overdosage | Administer 1 mg protamine for each 100 Units of heparin to be inactivated. Decrease protamine dose by ½ for every 30 minutes that have lapsed since heparin was administered | IV | Single dose | — | 🌎 NA |
- Heparin overdosage: Give slowly.
- Heparin overdosage: May be ineffective if heparin was given deep SC. Do not give faster than 50 mg over 10 minutes.
牛
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Bracken Fern (Pteridium spp.) poisoning | 1 injection of 10 mL of 1% protamine sulfate IV | IV | Single dose | — | 🌎 NA |
- Bracken Fern (Pteridium spp.) poisoning: In combination with whole blood (2.25-4.5 L)
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
プロタミン硫酸塩は、サケや関連魚類の精子または成熟精巣から得られる、単純で低分子量のカチオン性タンパク質です。獣医療においては、主にヘパリン過剰投与による重篤な出血に対する特異的な解毒剤として使用されます。
重要な臨床ポイント：
- 未分画ヘパリン vs 低分子量ヘパリン（LMWH）： プロタミンは未分画ヘパリンを完全に中和しますが、低分子量ヘパリン（ダルテパリンやエノキサパリンなど）の抗Xa活性は部分的にしか中和しません。ただし、LMWH過剰による微小血管出血を改善する効果はあります。
- その他の用途： 反芻動物におけるワラビ（Pteridium spp.）中毒の補助治療として提案されています。
臨床のポイント： プロタミンは異種タンパク質であるため、特に過去に投与歴がある患者や魚アレルギーのある患者では、過敏症反応（アナフィラキシーを含む）が起こる可能性があります。
作用機序
Protamine works via direct acid-base neutralization.
- Mechanism: Heparin is a strongly acidic molecule, while protamine is strongly basic.
- Pathway: Protamine → binds directly to circulating heparin → forms an inactive, stable salt complex → neutralizes heparin's anticoagulant activity.
Pharmacology Note: Protamine possesses weak intrinsic anticoagulant activity of its own. If administered in large doses without heparin present, it can theoretically interfere with coagulation, though this rarely causes clinical hemorrhage.
安全性・警告
禁忌
- Known hypersensitivity or intolerance to protamine
- Hypersensitivity to protamine
- Conditions where heparin has not been administered
有害事象
- Acute hypotension (if given too rapidly)
- Bradycardia
- Pulmonary hypertension
- Dyspnea
- Hypersensitivity/Anaphylaxis
- Heparin 'rebound' effect (bleeding hours after neutralization)
- Anaphylactoid reactions
- Paradoxical bleeding (at high doses)
注意事項
Administration Warnings
- Rate of Injection: Must be administered via slow IV injection (over 1-3 minutes). Rapid IV injection can cause severe acute hypotension, bradycardia, pulmonary hypertension, and dyspnea. Do not exceed a rate of 50 mg over a 10-minute period.
- Heparin Rebound: A 'rebound' effect may occur where anticoagulation and bleeding resume several hours after apparent neutralization. This is likely due to the release of heparin from extravascular compartments or degradation of the protamine-heparin complex by fibrinolysin.
- Pregnancy: FDA Category C. Use only if clearly needed.
医薬品相互作用
Forms a stable salt, causing the loss of anticoagulant activity of both compounds (therapeutic intent).
監視
- Coagulation parameters (e.g., aPTT, ACT) to assess heparin neutralization
- Blood pressure (monitor for hypotension during administration)
- Heart rate and rhythm (monitor for bradycardia)
- Respiratory rate and effort
- Signs of recurrent bleeding (heparin rebound effect) for several hours post-administration
- Coagulation times (aPTT, ACT)
- Signs of anaphylaxis during administration
薬物動態
半減期
吸収
Binds to heparin within 5 minutes after IV injection.
分布
Forms a complex with heparin in the intravascular space.
代謝
The exact metabolic fate is unknown, but evidence suggests the heparin-protamine complex is partially metabolized and/or degraded by fibrinolysin, which can free previously bound heparin.
消失
Clearance mechanisms are not fully defined, but degradation of the complex can lead to a clinical 'rebound' effect.
過剰投与
Because protamine has inherent, albeit weak, anticoagulant activity, massive overdoses could theoretically result in hemorrhage.
However, clinical data in humans suggests that significant overdoses (600-800 mg) typically result in only mild, transient effects on coagulation. The LD50 of protamine in mice is reported to be 100 mg/kg. Treatment of overdose should be supportive.
製品
製剤
- Injection: 10 mg/mL
- 10 mg/ml injectable solution
ヒト用医薬品
- Protamine Sulfate Injection: 10 mg/mL preservative-free in 5 mL and 25 mL vials
- Protamine sulphate 10 mg/ml solution for injection
規制ステータス
POM (Prescription Only Medicine)
POM (Prescription Only Medicine)
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Powder for injection: Store at room temperature (15-30°C). Liquid injection: Store in the refrigerator (2-8°C); avoid freezing (though stable at room temperature for at least 2 weeks). Reconstituted powder: Use immediately if mixed with Sterile Water for Injection, or within 72 hours if mixed with Bacteriostatic Water for Injection. Compatible with D5W, normal saline, cimetidine, and verapamil.
飼主向け情報
飼い主様への重要な情報
- 緊急時専用： プロタミン硫酸塩は、ヘパリンの過剰投与による重度の出血を治療するために、病院内でのみ使用される特殊な救命薬です。
- 集中的なモニタリング： 投与が早すぎると血圧や心拍数が急激に低下する可能性があるため、この薬を投与されている間、ペットはICUで注意深く監視されます。
- リバウンド出血： 治療が成功した後でも、ヘパリンの出血作用が「リバウンド」して再発することがあるため、数時間はペットを観察する必要があります。
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