二巰丙醇
二巰丙醇（Dimercaprol，又稱**英國抗路易斯毒氣劑**或**BAL**）是一種重金屬螯合劑，在獸醫學中主要用於治療**砷**中毒。它偶爾也用於鉛、汞和金中毒。 它最初在二戰期間開發，作為路易斯毒氣（一種含砷的化學戰劑）的解毒劑。它含有巰基，能與重金屬結合，防止它們干擾必需的細胞酶。 > **臨床要點：** 二巰丙醇配製於花生油中，必須進行深部肌肉注射，這可能會相當疼痛。它對某些金屬（如硒）相對無效，並且絕對禁忌用於鐵、鎘和硒中毒，因為產生的二巰丙醇-金屬複合物比單獨的金屬毒性更強。
作用機制: 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.
各物種劑量
- 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.
- Arsenic toxicity · 5 mg/kg IM initially, followed by 3 mg/kg IM q6h for remainder of first day, then 1 mg/kg IM q6h · IM · q6h · 2 or more additional days · Therapy is difficult due to large volumes required and painful IM route. Must be used acutely; delays significantly decrease effectiveness.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Impaired hepatic function (unless secondary to acute arsenic toxicity)
- Iron poisoning
- Cadmium poisoning
- Selenium poisoning
不良反應
- Pain at injection site
- Vomiting
- Seizures (at higher dosages)
- Transient increases in blood pressure
- Tachycardia
- Nephrotoxicity
藥物相互作用
- 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
監測
- Liver function
- Renal function
- Hemogram
- Hydration and perfusion status
- Electrolytes and acid/base status
- Urinary pH (maintain alkaline pH)
過量
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 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。