Busulfan
Busulfan is a chemotherapy medication classified as a bifunctional alkylating agent. It works by producing reactive carbonium ions that cross-link DNA in cells, preventing their replication and causing cell death. It is primarily used in the treatment of chronic myelogenous leukemia (CML) and as part of conditioning regimens prior to hematopoietic stem cell transplantation.
Busulfan is an alkylating chemotherapy agent used primarily for chronic myelogenous leukemia and bone marrow transplant conditioning.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- L01AB01
- RxNorm
- 1828
- Generic
- Busulfan
- Class
- atc-l01
- Brands
- Myleran, Busulfex
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- injection, tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
10 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks; busulfan is known to cause fetal harm and congenital malformations
regular fetal monitoring and ultrasound examinations
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
third trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks; consider alternative therapy
regular fetal monitoring and assessment of fetal growth
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingdo not breastfeed
busulfan is excreted in breast milk; discontinue breastfeeding during treatment and for at least 2 weeks after last dose
not applicable
Use of this medication in this population requires careful consideration of risks and benefits.
pediatric_age
childrenadjust dose based on body weight or body surface area
commonly used for hematopoietic stem cell transplantation conditioning in pediatric patients; requires careful monitoring
frequent CBC monitoring, liver function tests, renal function monitoring, and monitoring for veno-occlusive disease
Use with caution and monitor for adverse effects.
geriatric
elderlyno specific dose adjustment required; individualize therapy
use with caution due to potential decreased organ function; monitor closely for toxicity
frequent CBC, liver function tests, renal function tests, and monitoring for pulmonary toxicity
Use with caution and monitor for adverse effects.
renal_impairment
mild to moderateno initial dose adjustment needed for mild to moderate impairment
monitor renal function closely; dose adjustments may be needed based on clinical response and tolerability
regular monitoring of renal function and CBC
Use with caution and monitor for adverse effects.
renal_impairment
severeconsider dose reduction in severe renal impairment
use with caution in severe renal impairment; consider reducing dose and monitoring closely
frequent monitoring of renal function, CBC, and drug levels if available
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderateno standard dose adjustment; use with caution
use with caution in hepatic impairment; monitor liver function tests closely
frequent liver function tests, CBC, and monitoring for veno-occlusive disease
Use with caution and monitor for adverse effects.
hepatic_impairment
severeconsider dose reduction in severe hepatic impairment
use with extreme caution in severe hepatic impairment; benefits must outweigh risks
frequent monitoring of liver function, coagulation parameters, and clinical status
Use with caution and monitor for adverse effects.
Statistics and clinical data
FDA approval year
Initial FDA approval for treatment of chronic myeloid leukemia
Drug class
Busulfan is classified as an alkylating agent, specifically a busulfan derivative
Mechanism of action
Busulfan forms covalent bonds with DNA, causing crosslinking and inhibiting DNA replication
Primary indications
Main therapeutic uses in oncology
Chronic myelogenous leukemia (CML), myeloproliferative disorders, and as part of myeloablative conditioning prior to allogeneic hematopoietic stem cell transplantation for various hematologic malignancies and disorders.
As a bifunctional alkylating agent, busulfan hydrolyzes in aqueous media to release methanesulfonate groups that form reactive carbonium ions. These ions cross-link DNA strands, disrupting DNA replication and transcription, which leads to cell death, particularly in rapidly dividing cells like hematopoietic cells.
Significant myelosuppression is expected; regular blood count monitoring is essential. Seizure prophylaxis is often required due to CNS toxicity risk. Hepatotoxicity, pulmonary fibrosis, and secondary malignancies are potential long-term risks. Use requires specialized supervision by oncologists or transplant specialists in controlled settings.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy