Busulfan
**Busulfan** is a potent **bifunctional alkylating antineoplastic agent** primarily utilized in veterinary medicine for the adjunctive treatment of **chronic granulocytic leukemias (CML)** and **polycythemia vera** in small animals. * **Clinical Pearl**: While not commonly used in routine veterinary practice due to the advent of newer targeted therapies (such as hydroxyurea for polycythemia vera), it remains a viable option for specific myeloproliferative disorders. * It carries a significant risk of **severe myelosuppression**, necessitating rigorous hematological monitoring. * Therapy may elevate serum uric acid levels due to rapid tumor lysis and cellular breakdown, sometimes requiring concurrent allopurinol therapy to prevent uric acid nephropathy.
กลไกการออกฤทธิ์: Busulfan is a **cell cycle-phase nonspecific** alkylating agent. * **Mechanism**: It undergoes intracellular hydrolysis to release methanesulfonate groups → forms reactive carbonium ions → **alkylates DNA** by cross-linking guanine bases on DNA strands. * **Pathway**: DNA cross-linking → inhibition of DNA replication and RNA transcription → **apoptosis** (programmed cell death). * **Target**: It exhibits highly selective toxicity toward cells of the **granulocytic series** and myeloid precursors in the bone marrow, making it particularly effective against myeloproliferative diseases.
ขนาดยาตามชนิดสัตว์
- Adjunctive therapy of chronic granulocytic leukemias or polycythemia vera · 2-4 mg/m2 · PO · once daily · NOT mg/kg. Rarely used in veterinary medicine.
- Adjunctive therapy of chronic granulocytic leukemias or polycythemia vera · 2-4 mg/m2 · PO · once daily · NOT mg/kg. Rarely used in veterinary medicine.
ขนาดยาเป็นข้อมูลอ้างอิงทางคลินิกสำหรับสัตวแพทย์ผู้มีใบอนุญาต โปรดตรวจสอบกับฉลากล่าสุดและผู้ป่วยแต่ละรายเสมอ
วิธีการให้ยา
ข้อห้ามใช้
- Patients with known hypersensitivity to busulfan
- Patients who have shown resistance to the drug in the past
- Pregnancy (FDA Category D), unless potential benefits outweigh the risks
- Nursing dams
อาการไม่พึงประสงค์
- Myelosuppression (anemia, leukopenia, thrombocytopenia)
- Pancytopenia (can take months to years for recovery)
- Bronchopulmonary dysplasia with pulmonary fibrosis (uncommon, chronic use)
- Uric acid nephropathy
- Stomatitis
อันตรกิริยาระหว่างยา
- Acetaminophen · Use within 72 hours prior to busulfan can reduce busulfan clearance by reducing glutathione concentrations in tissues and blood.
- Cyclophosphamide · Can potentially reduce clearance of busulfan, probably by competing for available glutathione.
- Itraconazole · Potential decreased busulfan clearance.
- Myelosuppressant agents · Concurrent use with other bone marrow depressant medications may result in additive myelosuppression.
- Phenytoin · Possible increased clearance of busulfan.
- Thioguanine · Used concomitantly with busulfan may result in hepatotoxicity.
การติดตาม
- CBC (Complete Blood Count)
- Serum uric acid
- Clinical efficacy
การได้รับยาเกินขนาด
There is limited experience with busulfan overdoses. The LD50 in mice is 120 mg/kg. * **Chronic vs Acute**: Chronic overdosage is more likely to cause serious bone marrow suppression than is an acute overdose. * **Treatment**: Any overdose should be treated seriously with standard gut emptying protocols used when appropriate and supportive therapy initiated when required. * **Antidote**: There is no known specific antidote for busulfan intoxication.
ข้อมูลอ้างอิงยาของ VetSheet มีไว้สำหรับสัตวแพทย์ผู้มีใบอนุญาตเพื่อช่วยในการตัดสินใจทางคลินิก ไม่ใช่สิ่งทดแทนการวินิจฉัยของผู้เชี่ยวชาญหรือฉลากล่าสุดของผู้ผลิต