放線菌素D (Dactinomycin)
Dactinomycin
Actinomycin D
別名: Cosmegen · Lyovac · Actinomycin D · DTIC · actinomycin C(1) · meractinomycin · NSC-3053 · Ac-De · Bioact-D · Dacmozen
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
這是按體表面積（mg/m²）計算的劑量；給藥前須先把體重換算為體表面積。
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Antineoplastic protocols (e.g., rescue therapy for lymphomas, sarcomas) | 0.5-1 mg/m 2 (NOT mg/kg) | IV | over 20 minutes; repeated at 1-3 week intervals | Depending on the protocol | 🌎 NA |
| Lymphoma (rescue protocols), sarcomas, and carcinomas | 0.5-0.75 mg/m2 | IV | q2-3wk | Administer slowly over 20 min | 🌍 EU |
- Antineoplastic protocols (e.g., rescue therapy for lymphomas, sarcomas): Dose is based on body surface area (m2). Consultation with a veterinary oncologist is strongly recommended.
- Lymphoma (rescue protocols), sarcomas, and carcinomas: Must be administered via a preplaced catheter due to vesicant properties.
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
概覽
Dactinomycin（又稱 Actinomycin D）是一種從微小鏈黴菌 (Streptomyces parvullus) 中提取的注射用抗腫瘤抗生素。在獸醫腫瘤學中，主要用於小動物淋巴網狀內皮腫瘤、骨與軟組織肉瘤及癌的輔助治療，也是犬淋巴瘤救援療法的用藥之一。
臨床要點與特徵：
- 發泡劑 (Vesicant)： 具有強烈刺激性，若藥物外滲會導致嚴重的組織壞死與脫落，必須確保靜脈導管留置完美。
- MDR1 基因突變： 該藥物由 P-醣蛋白 (P-gp) 幫浦主動運輸。帶有 ABCB1 (MDR1) 基因突變的犬種（如牧羊犬、澳洲牧羊犬）具有極高的致命毒性風險，強烈建議用藥前進行基因檢測。
- 毒性特徵： 具有顯著的骨髓抑制與胃腸道毒性，可能危及生命。
作用機制
Dactinomycin is a cell-cycle phase-nonspecific antineoplastic agent.
- Intercalation: The drug intercalates into the minor groove of the DNA double helix, specifically between adjacent guanine-cytosine base pairs.
- Transcription Inhibition: This stable dactinomycin-DNA complex physically blocks the progression of DNA-dependent RNA polymerase → inhibits transcription of messenger RNA (mRNA) → disrupts protein synthesis and leads to cell death.
- It also possesses some immunosuppressive and hypocalcemic properties.
安全性與警告
禁忌症
- Hypersensitivity to dactinomycin
- Pregnancy (teratogenic and embryotoxic)
不良反應
- Bone marrow depression (anemia, leukopenia, thrombocytopenia)
- Gastrointestinal toxicity (diarrhea, ulcerative stomatitis, GI ulceration)
- Severe tissue damage and pain (if extravasated)
- Hyperuricemia (may require allopurinol)
- Hepatotoxicity
注意事項
WARNING: Severe Vesicant and Highly Toxic
- Extravasation Risk: Can cause extensive pain and tissue damage. Must be administered via a perfectly placed IV catheter, ideally using a 'two-needle' technique and slow infusion into a running IV line.
- MDR1 Mutation: Use with extreme caution or avoid in breeds susceptible to the MDR1-allele mutation (Collies, Australian Shepherds, Shelties, Long-haired Whippets) due to high risk of fatal toxicity.
- Organ Dysfunction: Use with caution in patients with preexisting bone marrow depression, hepatic dysfunction, or active infections.
- Hazardous Drug: Chronic exposure increases mutagenic, teratogenic, and carcinogenic risks for healthcare workers. Strict hazardous drug handling, preparation, and disposal protocols are required.
- Pregnancy/Nursing: Embryotoxic and teratogenic (FDA Category C). Avoid use in pregnant or nursing animals.
藥物相互作用
Additive cardiotoxicity may occur if used concurrently or sequentially.
May cause additive myelosuppression.
Patients may require higher dosages of vitamin K when receiving dactinomycin.
監測
- Efficacy (tumor measurement/response)
- Complete Blood Count (CBC) with differential and platelets (prior to each dose and at nadir)
- Hepatic function tests
- Oral cavity examinations (check for ulcerative stomatitis)
- IV catheter site for any signs of extravasation during administration
藥物動力學
吸收
Poorly absorbed from the GI tract; must be administered intravenously.
分佈
Rapidly distributed into tissues. High concentrations are found in bone marrow and nucleated cells. It crosses the placenta.
代謝
Undergoes minimal hepatic metabolism.
排除
The majority of the drug is excreted unchanged in the bile and urine.
過量
Due to the extreme toxic potential of this agent, iatrogenic overdoses must be strictly avoided. Double-check all dosage calculations (ensure dosing is in mg/m2, not mg/kg). Overdose will result in severe, potentially fatal bone marrow suppression and gastrointestinal ulceration. Treatment is entirely symptomatic and supportive (e.g., broad-spectrum antibiotics, blood transfusions, aggressive fluid therapy, GI protectants).
可用產品
劑型
- Powder for injection (lyophilized)
人用標示
- Dactinomycin Powder for Injection, lyophilized: 500 micrograms with mannitol 20 mg in vials; Cosmegen® (Merck); (Rx)
各地核准狀態
POM (Prescription Only Medicine). Handled under strict cytotoxic safety regulations.
POM (Prescription Only Medicine).
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store the commercially available powder at room temperature and protect from light. Reconstitution: Must use sterile water for injection without preservatives, as preservatives will cause precipitation. Use the solution immediately after reconstitution and discard any unused portion. If stored in the refrigerator, it loses 2-3% potency over 6 hours. Note: IV fluid sterilizing filters (cellulose ester membrane) may partially remove the drug.
飼主須知
Dactinomycin 是一種用於治療特定癌症的強效化療藥物。由於其藥效強烈，需要密切的監測。
- 毒性徵兆： 如果您的寵物出現嚴重不適的跡象，包括血便或吐血、異常出血或瘀傷、排尿困難、嚴重精神沉鬱、感染跡象（發燒）或呼吸急促，請立即聯繫您的獸醫師。
- 口腔潰瘍： 請定期檢查寵物的口腔是否有破皮或潰瘍，這可能會導致牠們進食疼痛。
- 居家安全： 由於此藥物會經由寵物的排泄物排出，且具有潛在的細胞毒性，在治療後的幾天內，處理寵物的尿液、糞便或嘔吐物時請戴上手套，處理後請徹底洗手。
- 繁殖/懷孕： 此藥物會導致胎兒畸形。接受此藥物治療的寵物不可進行繁殖。
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