脂肪乳剤（静注用）
**静注用脂肪乳剤 (IFE/ILE)** は、静脈内投与用に調製された無菌で発熱性物質を含まない脂肪乳剤です。 歴史的には主に**経静脈的なカロリーおよび必須脂肪酸の供給源**として利用されてきましたが、現在では獣医毒性学における重要な**救命解毒剤**として注目されています。従来の治療法が効かない場合、脂溶性の高い薬物による生命を脅かす中毒の治療に極めて有効です。 **主な臨床応用:** * **中毒の救命治療:** 局所麻酔薬（ブピバカイン、リドカイン）、大環状ラクトン類（イベルメクチン、モキシデクチン）、カルシウム拮抗薬（アムロジピン）、β遮断薬、および一部の抗うつ薬/抗精神病薬。 * **経静脈栄養 (PN):** 高密度のカロリーを提供します（20%溶液で約2 kCal/mL）。*注意: 免疫抑制や感染リスクの可能性があるため、重症患者の栄養管理への使用には議論があります。*
作用機序: **Toxicologic Mechanism (Antidote):** * **"Lipid Sink" Theory:** IFE creates an expanded intravascular lipid phase. Highly lipophilic toxins partition out of target tissues (e.g., myocardium, CNS) and into this "lipid sink" within the plasma, reducing the free (active) drug concentration at receptor sites. * **Metabolic/Cardiac Enhancement:** Provides a direct energy substrate (free fatty acids) to the myocardium, overcoming mitochondrial lipid metabolism blockade (e.g., by bupivacaine) and increasing intracellular calcium to improve cardiac contractility. **Nutritional Mechanism:** * Provides a dense source of calories and essential fatty acids (linoleic, linolenic acids) necessary for cellular integrity and metabolism.
動物種別の用量
- Parenteral Nutrition (PN) · 25-60% of calories administered. Traditionally not recommended at > 2 g/kg/day for TPN therapy. · IV · CRI · As needed · Consult a veterinary nutritionist.
- Rescue agent for fat-soluble drug/toxin intoxication · IFE 20% via a sterile, peripheral IV catheter as a 1.5 mL/kg bolus over 1-3 minutes, then 0.25-0.5 mL/kg/min for 30-60 min. The bolus could be repeated in case of cardiac arrest. If symptomatic after traditional dosing, consider additional doses of 1.5 mL/kg IV over 30 min q4-6h for 24-36 hours until clinical signs resolve, or maintaining a CRI of 0.5 mL/kg/hour until clinical signs resolve. · IV · Bolus followed by CRI · Until clinical signs resolve · Extrapolated from general veterinary/human guidelines.
- Parenteral Nutrition (PN) · 25-60% of calories administered. Traditionally not recommended at > 2 g/kg/day for TPN therapy. · IV · CRI · As needed · Consult a veterinary nutritionist. Keep PPN solutions below 600 mOsm/L.
- Rescue agent for fat-soluble drug/toxin intoxication · IFE 20% via a sterile, peripheral IV catheter as a 1.5 mL/kg bolus over 1-3 minutes, then 0.25-0.5 mL/kg/min for 30-60 min. The bolus could be repeated in case of cardiac arrest. If symptomatic after traditional dosing, consider additional doses of 1.5 mL/kg IV over 30 min q4-6h for 24-36 hours until clinical signs resolve, or maintaining a CRI of 0.5 mL/kg/hour until clinical signs resolve. · IV · Bolus followed by CRI · Until clinical signs resolve · Do not exceed 8 mL/kg/day generally, though this has been exceeded in acute toxicosis without ill effect.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Severe egg yolk allergies
- Abnormal fat metabolism
- Premature and low-birth weight infants (human black box warning)
- Blood coagulation disorders
- Pulmonary disease
- Renal impairment
- Severe liver damage
- Patients at high risk for fat emboli
有害事象
- Sepsis or thrombophlebitis (secondary to IV catheterization)
- Fat overload syndrome (hyperlipidemia, hepatomegaly, icterus, splenomegaly, fat embolism, thrombocytopenia, hemolysis, prolonged clotting times)
- Pulmonary toxicity (temporary)
- GI effects
- Somnolence
- Headache
- Flushing
- Pancreatitis
- Hypercoagulability
- Hypersensitivity
薬物相互作用
- Lipid Soluble Drugs · IFE may act as a 'lipid sink', reducing the free circulating levels and clinical efficacy of concurrently administered lipophilic medications.
モニタリング
- Serum/plasma drug levels (for toxicology tracking)
- Blood glucose
- Serum triglycerides and gross lipemia
- PCV and Total Protein
- IV catheter site status (phlebitis/sepsis)
- Hydration status and vital signs (temp, HR, RR)
- Serum electrolytes (including phosphorus)
- Renal and liver function tests
- CBC
- Coagulation times (if using heparin)
過量投与
In the event of inadvertent overdose or severe fat overload, **stop the infusion** until the lipid has cleared from the plasma. Clearance can be evaluated visually (inspecting hematocrit tubes for lipemia) or via laboratory methods (triglyceride concentrations, nephelometry). If severe hyperlipidemia occurs during toxicity treatment, **heparin therapy (75-250 Units/kg SQ q6h)** may be considered to increase lipid clearance via lipoprotein lipase activation. However, weigh risks carefully, as heparin may alter the antidote mechanism. Monitor PTT; if PTT exceeds 2-2.5X normal, lower heparin dose (75 Units/kg SQ q6-8h) or discontinue.
VetSheet の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。