Busulphan, Alkylating agent

• Carbonium ions are rapidly formed after systemic absorption of busulfan leading to alkylation of DNA. This results in breaks in the DNA molecule as well as cross-linking of the twin strands, thus interfering with DNA replication and transcription of RNA. The antitumour activity of busulfan is cell cycle phase-nonspecific.
• endocardiac fibrosis (rare), seizures (10%, with BMT doses), mucositis (with high dose therapy), myelosuppression, veno-occlusive disease (25%, in adults; 8% in children, with BMT doses), pulmonary toxicity (3%, dyspnea, dry cough, fever and rales), hyperuricemia (during periods of active cell lysis)