Myleran (Busulfan)

• Busulfan is an alkylating chemotherapy agent used in specific hematologic malignancies and transplant preparation.
• Chronic myeloid leukemia (CML): provides disease control by reducing leukemic cell proliferation.
• Conditioning regimen for bone marrow transplantation: delivers myeloablation to facilitate donor cell engraftment.

• Busulfan exerts its antineoplastic effect by alkylating DNA strands, forming cross‑links that impede DNA replication and transcription. This disruption leads to cell cycle arrest and apoptosis, preferentially affecting rapidly dividing malignant hematopoietic cells while sparing most normal tissues.

Busulfan may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Nausea and vomiting
• Mucositis or oral ulceration
• Alopecia (hair loss)
• Skin rash or discoloration

Serious or Rare Side Effects

• Pulmonary fibrosis or interstitial lung disease
• Hepatic veno‑occlusive disease (VOD)
• Severe bone marrow suppression leading to pancytopenia
• Seizures, especially at high plasma concentrations
• Secondary malignancies with long‑term use
• Life‑threatening infections due to immunosuppression

Before initiating therapy, several safety considerations should be addressed.

• Monitor blood counts: perform regular complete blood counts to detect myelosuppression.
• Assess liver function: evaluate hepatic enzymes and bilirubin prior to dosing.
• Evaluate pulmonary status: baseline lung function tests are recommended.
• Avoid in patients with known hypersensitivity to busulfan or related alkylating agents.
• Adjust dose in hepatic impairment: consider reduced dosing or increased monitoring.
• Store at below 25°C: keep in the original container, protect from moisture and direct sunlight.

Busulfan can interact with other medicines, influencing its efficacy or toxicity.

Major Interactions (Avoid)

• Cyclophosphamide: combined use increases risk of severe myelosuppression.
• Azathioprine: concurrent administration may potentiate bone marrow toxicity.
• Phenytoin: enzyme induction reduces busulfan plasma levels, compromising therapeutic effect.

Moderate Interactions (Monitor Closely)

• Azole antifungals (e.g., fluconazole, itraconazole): may raise busulfan concentrations, requiring dose adjustment.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): increase bleeding risk when thrombocytopenia is present.
• Acetaminophen: concurrent high‑dose use may add hepatic stress, warranting liver function monitoring.