ジメルカプロール
ジメルカプロール（別名**BAL**または**英国抗ルイサイト剤**）は、獣医学において主に**ヒ素**中毒の治療に使用される重金属キレート剤です。鉛、水銀、金の中毒にも使用されることがあります。 第二次世界大戦中にルイサイト（ヒ素系化学兵器）の解毒剤として開発されました。重金属と結合するスルフヒドリル基を含み、必須細胞酵素の阻害を防ぎます。 > **臨床上のポイント：** ピーナッツオイルに溶解されており、深部筋肉内注射で投与する必要がありますが、強い痛みを伴います。セレンなどの一部の金属には効果が薄く、鉄、カドミウム、セレン中毒には絶対禁忌です（形成される複合体が金属単体よりも強い毒性を持つため）。
作用機序: Heavy metals exert their toxic effects by binding to **sulfhydryl (-SH) groups** on essential cellular enzymes, leading to enzyme inactivation. Dimercaprol contains two sulfhydryl groups that act as "decoys." * **Dimercaprol + Heavy Metal → Heterocyclic Ring Complex** * This complex is more stable than the metal-enzyme bond, allowing the metal to be pulled away from the tissues and excreted via the kidneys and feces. > **Mechanistic Note:** The chelation is not irreversible. The complex can dissociate as dimercaprol concentrations decrease, if oxidized, or in an acidic environment. Therefore, **alkalinizing the urine** is crucial to prevent the complex from dissociating in the kidneys and causing nephrotoxicity.
動物種別の用量
- Arsenic toxicity · 2.5-5 mg/kg IM · IM · q4h for first 2 days; q8h on 3rd day; BID for next 10 days · Until recovery · Intensive supportive care required. 5 mg/kg dose only for acute cases and only for the first day. Give with sodium thiosulfate.
- Arsenic toxicity · 2.5-5 mg/kg IM · IM · q4h for first 2 days, then q12h · Until recovery · If ingestion was within 36 hours. Use emetics/gastric lavage if recent. Institute fluid therapy.
- Arsenic toxicity · 4 mg/kg IM · IM · q4-6h · Max 4 continuous days · Do not give for more than 4 continuous days.
- Arsenic toxicity · 5 mg/kg IM loading dose, then 2.5 mg/kg IM · IM · q3-4h for two days, then progressively lengthen to q12h · Until recovery · Loading dose of 5 mg/kg for acute cases only.
- Arsenic toxicity (no clinical signs) · 3 mg/kg IM · IM · q8h
- Arsenic toxicity (clinical signs) · 6 mg/kg IM · IM · q8h · 3-5 days
- Arsenic, lead or mercury poisoning · 2.5-5 mg/kg IM · IM · q4h · 2 days · Efficacy questionable unless given before signs appear or very early. Withdrawal info not available.
- Mercury toxicity · 3 mg/kg IM · IM · four times daily for 3 days, then twice daily · 13 days total · Treatment is often unsuccessful.
投与経路
禁忌
- Impaired hepatic function (unless secondary to acute arsenic toxicity)
- Iron poisoning
- Cadmium poisoning
- Selenium poisoning
有害事象
- Pain at injection site
- Vomiting
- Seizures (at higher dosages)
- Transient increases in blood pressure
- Tachycardia
- Nephrotoxicity
薬物相互作用
- Iron · Forms a highly toxic complex. Do not administer with iron salts; wait at least 24 hours after the last dimercaprol dose before starting iron therapy.
- Selenium · Forms a highly toxic complex. Do not administer with selenium salts; wait at least 24 hours after the last dimercaprol dose before starting selenium therapy. · major
- Cadmium · Forms a highly toxic complex. · major
- Uranium · Forms a highly toxic complex.
- Iron supplements · Forms highly toxic complexes · major
モニタリング
- Liver function
- Renal function
- Hemogram
- Hydration and perfusion status
- Electrolytes and acid/base status
- Urinary pH (maintain alkaline pH)
過量投与
Clinical signs of dimercaprol overdosage in animals include **vomiting, seizures, tremors, coma, and death**. No specific doses were located to correspond with these clinical signs. Treatment should be supportive and symptomatic.
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。