博來黴素
博來黴素是一種源自*Streptomyces verticillus*的糖肽類抗腫瘤抗生素。 **主要臨床用途：** * 用於犬貓淋巴瘤、鱗狀細胞癌 (SCC)、畸胎瘤和非功能性甲狀腺腫瘤的輔助治療。 * **電化學療法 (ECT)：** 當與病灶內電穿孔技術結合使用時，博來黴素非常有效，能顯著增加局部腫瘤（如貓鼻鏡鱗狀細胞癌、犬肥大細胞瘤）的細胞內藥物濃度。 **毒性特徵：** 與許多傳統化療藥物不同，博來黴素通常**不會對骨髓造成嚴重抑制**。然而，它具有引起**肺纖維化**和皮膚毒性的顯著風險。這種獨特的毒性特徵是因為肺部和皮膚缺乏能使該藥物失去活性的*博來黴素水解酶 (bleomycin hydrolase)*。
作用機制: Bleomycin acts primarily by inducing **single- and double-strand DNA breaks**. * **Mechanism:** The drug possesses a DNA-binding domain and an iron-binding domain. It binds to DNA and chelates intracellular **Fe²⁺** (ferrous iron). * **Oxidative Cleavage:** The Bleomycin-Fe²⁺ complex reacts with oxygen to generate highly reactive oxygen species (ROS), such as superoxide and hydroxyl radicals → oxidative cleavage of the DNA phosphodiester backbone. * **Cell Cycle:** It is considered cell-cycle phase-specific, primarily arresting cells in the **G2 and M phases**. * **Resistance:** Mediated by decreased cellular uptake, increased DNA repair mechanisms, or increased cellular expression of **bleomycin hydrolase** (the enzyme responsible for its degradation).
各物種劑量
- Antineoplastic therapy (General guide) · 10 Units mg/m2 (NOT mg/kg) or 0.3-0.5 mg/kg · Parenteral · Varies (e.g., once daily for a few days then once weekly, or once weekly at the start) · Do not exceed total maximum dosage of 125-200 mg/m2 · 1 Unit = 1 mg. Consultation with a veterinary oncologist is strongly recommended.
- Antineoplastic therapy (General guide) · 10 Units mg/m2 (NOT mg/kg) or 0.3-0.5 mg/kg · Parenteral · Varies (e.g., once daily for a few days then once weekly, or once weekly at the start) · Do not exceed total maximum dosage of 125-200 mg/m2 · 1 Unit = 1 mg. Consultation with a veterinary oncologist is strongly recommended.
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
- Prior hypersensitivity reactions to the drug
- Preexisting pulmonary disease
- Adverse pulmonary effects from prior therapy
- Pregnancy (unless owners accept the associated teratogenic risks)
不良反應
- Fever
- Anorexia
- Vomiting
- Allergic reactions (including anaphylaxis)
- Alopecia
- Skin rashes
- Stomatitis
- Pneumonitis
- Pulmonary fibrosis (potentially fatal)
- Thrombocytopenia (mild)
- Leukopenia (mild)
- Decreased hemoglobin
- Renal toxicity
- Hepatotoxicity
藥物相互作用
- General Anesthetics · Bleomycin sensitizes lung tissue to oxygen. Use of general anesthetics can cause rapid deterioration of pulmonary function and post-operative pulmonary fibrosis, even at safe inspired oxygen concentrations.
- Other Chemotherapy Agents or Radiation Therapy · Prior or concomitant use can lead to increased hematologic, mucosal, and pulmonary toxicities.
監測
- Efficacy (tumor response)
- Pulmonary Toxicity: Chest radiographs (baseline and regularly, e.g., q1-2 weeks), lung auscultation (monitor for dyspnea and fine rales)
- Blood chemistry (renal and hepatic function markers)
- Hematologic profiles (CBC)
- Total cumulative dose accumulation (do not exceed 125-200 mg/m2)
過量
No specific information was located in the monograph. Because of the high toxicity and low therapeutic index of the drug, it is critical to determine dosages carefully. Overdosage would likely manifest as severe exacerbations of acute toxicities (anaphylaxis, fever, vomiting) and accelerated onset of delayed toxicities (pulmonary fibrosis, stomatitis).
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。