Busulfan: uses, dosing, side effects & brands
Busulfan is an alkylating drug sold in the U.S. under 3 brand and generic names, for polycythemia vera, bcr-abl positive chronic myelogenous leukemia and primary myelofibrosis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Alkylating Drug
- Treats (across its forms)
- Polycythemia Vera, Bcr-Abl Positive Chronic Myelogenous Leukemia and Primary Myelofibrosis
- Available as
- Injectable · Solution · Tablet
- Sold as
- 3 products — Busulfan, Busulfex and Myleran
- Prescription?
- Prescription only
- Generic available?
- Yes
- Boxed warning
- Boxed warning
How Busulfan is dosed
From the FDA label for Busulfan (application ANDA205139). Other busulfan products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Pre-medicate with anticonvulsants (e.g. benzodiazepines, phenytoin, valproic acid or levetiracetam) and antiemetic. ( 2.1 , 5.2 ) Dilute and administer as intravenous infusion. Do not administer as intravenous push or bolus. ( 2.1 , 2.3 ) Recommended adult dose: 0.8 mg per kg of ideal body weight or actual body weight, whichever is lower, administered intravenously via a central venous catheter as a two-hour infusion every six hours for four consecutive days for a total of 16 doses. ( 2.1 ) 2.1 Initial Dosing Information Administer Busulfan Injection in combination with cyclophosphamide as a conditioning regimen prior to bone marrow or peripheral blood progenitor cell replacement. For patients weighing more than 12 kg, the recommended doses are: Busulfan Injection 0.8 mg per kg (ideal body weight or actual body weight, whichever is lower) intravenously via a central venous catheter as a two-hour infusion every six hours for four consecutive days for a total of 16 doses (Days -7, -6, -5 and -4). Cyclophosphamide 60 mg per kg intravenously as a one-hour infusion on each of two days beginning no sooner than six hours following the 16 th dose of Busulfan Injection (Days -3 and -2). Administer hematopoietic progenitor cells on Day 0. Premedicate patients with anticonvulsants (e.g., benzodiazepines, phenytoin, valproic acid or levetiracetam) to prevent seizures reported with the use…
Everything below is the FDA label for Busulfan (injectable, solution). Busulfan is also sold as tablet, and those are different medicines to take — follow the label for the one you were prescribed.
Busulfan side effects
The following adverse reactions are discussed in more detail in other sections of the labeling: Myelosuppression [see Warnings and Precautions (5.1) ] Seizures [see Warnings and Precautions (5.2) ] Hepatic Veno-Occlusive Disease (HVOD) [see Warnings and Precautions (5.3) ] Embryo-fetal Toxicity [see Warnings and Precautions (5.4) ] Cardiac Tamponade [see Warnings and Precautions (5.5) ] Bronchopulmonary Dysplasia [see Warnings and Precautions (5.6) ] Cellular Dysplasia [see Warnings and Precautions (5.7) ] Most common adverse reactions (incidence > 60%) were: myelosuppression, nausea, stomatitis, vomiting, anorexia, diarrhea, insomnia, fever, hypomagnesemia, abdominal pain, anxiety, headache, hyperglycemia and hypokalemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Hospira, Inc. at 1-800-441-4100 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse reaction information is primarily derived from the clinical study (N=61) of Busulfan Injection and the data obtained for high-dose oral busulfan conditioning in the setting of randomized, controlled trials identified through a…
Who shouldn’t take Busulfan
Busulfan Injection is contraindicated in patients with a history of hypersensitivity to any of its components. Busulfan Injection is contraindicated in patients with a history of hypersensitivity to any of its components. ( 4 )
Busulfan drug interactions
Drugs that Decrease Busulfan Injection Clearance: Metronidazole, itraconazole, iron chelating agents, acetaminophen. ( 7.1 ) Drugs that Increase Busulfan Injection Clearance: Phenytoin. ( 7.2 ) 7.1 Drugs that Decrease Busulfan Injection Clearance Itraconazole decreases busulfan clearance by up to 25%. Metronidazole decreases the clearance of busulfan to a greater extent than does itraconazole; metronidazole coadministration has been associated with increased busulfan toxicity. Fluconazole (200 mg) has been used with Busulfan Injection. Decreased clearance of busulfan was observed with concomitant use with deferasirox. The mechanism of this interaction is not fully elucidated. Discontinue iron chelating agents well in advance of administration of Busulfan Injection to avoid increased exposure to busulfan. Because busulfan is eliminated from the body via conjugation with glutathione, use of acetaminophen prior to (less than 72 hours) or concurrent with Busulfan Injection may result in reduced busulfan clearance based upon the known property of acetaminophen to decrease glutathione levels in the blood and tissues. 7.2 Drugs that Increase Busulfan Injection Clearance Phenytoin increases the clearance of busulfan by 15% or more, possibly due to the induction of glutathione-S-transferase. Since the pharmacokinetics of Busulfan Injection were studied in patients treated with phenytoin, the clearance of Busulfan Injection at the recommended dose may be lower and exposure (AUC) higher in patients not treated with phenytoin.
Every busulfan product we track (3)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 72/100 | Prescription | Injectable | No data | — | View → | |
| 2 | Not yet rated | Prescription | Injectable | No data | — | View → | |
| 3 | Not yet rated | Prescription | Tablet | No data | — | View → |
What busulfan pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| GX;EF3;M | 2 mg | white | round | — |
Busulfan recalls
From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.
Busulfan and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for busulfan: levels in milk, effects in breastfed infants, and the drugs it would consider insteadMost sources consider breastfeeding to be contraindicated during maternal antineoplastic drug therapy. It might be possible to breastfeed safely with busulfan during intermittent therapy with an appropriate period of breastfeeding abstinence. Although minimal data are available to determine an appropriate period to withhold breastfeeding, the drug's terminal half-live of 2.5 hours suggests that at least 24 hours may be sufficient. Chemotherapy may adversely affect the normal microbiome and chemical makeup of breastmilk. Women who receive chemotherapy during pregnancy are more likely to have difficulty nursing their infant.
National Institute of Child Health and Human Development, record revised August 16, 2021. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about busulfan
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 15,935 reports naming busulfan, and the FDA flagged 95% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- mucosal inflammation1,087 reports
- graft versus host disease975 reports
- venoocclusive liver disease932 reports
- cytomegalovirus infection885 reports
- acute graft versus host disease863 reports
- febrile neutropenia860 reports
- pyrexia824 reports
- chronic graft versus host disease648 reports
Read these as a signal, not a rate. A report does not mean busulfan caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label.
Source: openFDA drug/event (FAERS), retrieved September 25, 2026.
Related calculators
Frequently asked questions
What is Busulfan?
Busulfan is an alkylating drug used to treat Polycythemia Vera, Bcr-Abl Positive Chronic Myelogenous Leukemia, Primary Myelofibrosis.
What kind of drug is busulfan?
The FDA classifies busulfan as an alkylating drug. Alkylating chemotherapy drugs attach chemical groups to a cell's DNA, forming cross-links that lock the two DNA strands together. This damage stops the cell from copying its DNA and dividing, which triggers it to die; because they are not limited to one phase of the cell cycle, they can act on cells whether or not they are actively dividing. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take busulfan with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run busulfan against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is busulfan sold under?
We track 3 busulfan-containing products in the U.S.: Busulfan, Busulfex and Myleran. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does busulfan come in?
Across the brands we track, busulfan is currently marketed as injectable, solution and tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic busulfan?
Yes. Our catalog lists 1 generic busulfan product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Has busulfan been recalled?
The FDA's Enforcement database lists 1 recall record whose product description mentions busulfan. The most recent: Busulfan Injection (May 4, 2026). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Busulfan: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/busulfan
- MLA
- “Busulfan: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/busulfan.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for busulfan on DailyMed (NIH) ↗ — including its boxed warning in full.