Reviewed on 11/2/2022

What Is Busulfan and How Does It Work?

Busulfan is a prescription medication used for the treatment of chronic myelogenous leukemia

What Are Side Effects Associated with Using Busulfan?

Common side effects of Busulfan include:

  • nausea,
  • vomiting,
  • diarrhea,
  • constipation,
  • loss of appetite,
  • weight loss,
  • mouth sores,
  • upset stomach,
  • abdominal pain,
  • dizziness,
  • weakness,
  • swelling of the ankles/feet/hand,
  • flushing (warmth,
  • redness, or tingly feeling),
  • headache,
  • trouble sleeping,
  • swelling or irritation around the IV needle,
  • missed menstrual periods,
  • hair loss,
  • darkened skin color, and
  • fatigue.

Serious side effects of Busulfan include:

  • pale skin,
  • lightheadedness,
  • shortness of breath,
  • trouble concentrating,
  • easy bruising,
  • unusual bleeding,
  • purple or red pinpoint spots under the skin,
  • signs of infection (such as fever, chills, sore throat, flu symptoms, loss of appetite, weight loss, unusual weakness, mouth and throat ulcers, rapid and shallow breathing),
  • weight gain,
  • stomach swelling or tenderness,
  • yellowing of the skin or eyes (jaundice),
  • coughing up blood,
  • stomach pain,
  • sharp chest pain,
  • trouble breathing,
  • lower back pain,
  • blood in your urine,
  • urinating less than usual or not at all,
  • confusion,
  • jerking muscle movements,
  • muscle tightness or contraction,
  • overactive reflexes,
  • muscle weakness or limp feeling,
  • leg discomfort,
  • numbness or tingly feeling around the mouth,
  • fast/slow/uneven heart rate,
  • weak pulse,
  • confusion,
  • fainting,
  • seizures (convulsions),
  • persistent cough,
  • congestion, or
  • low fever

Rare side effects of Busulfan include:

  • none

Seek medical care or call 911 at once if you have the following serious side effects:

  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.


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What Are Dosages of Busulfan?

Adult dosage

Injectable solution

  • 6 mg/mL


  • 2 mg

Chronic Myelogenous (Myeloid, Myelocytic, Granulocytic) Leukemia

Adult and geriatric dosage

  • Remission induction: 60 mcg/kg/day or 1.8 mg/m²; 4-8 mg orally every day usual range  
  • Maintenance doses: 1-4 mg/day to 2 mg/week orally to maintain WBC 10,000-20,000 cells/mm³ may withhold drug when leukocyte count has declined to approximately 15,000/mcL
  • Examine the patient at monthly intervals and resume treatment with induction dosage when the total leukocyte count reaches approximately 50,000/mcL
  • Administered as component of busulfan/cyclophosphamide: 0.8 mg/kg IV every 6 hours for 4 days (in combo with cyclophosphamide) until WBC count= 15,000/mm³

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What Other Drugs Interact with Busulfan?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Busulfan has severe interactions with no other drugs.
  • Busulfan has serious interactions with at least 22 other drugs.
  • Busulfan has moderate interactions with at least 54 other drugs.
  • Busulfan has minor interactions with the following drugs:

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.

What Are Warnings and Precautions for Busulfan?


  • Hypersensitivity, resistance to busulfan
  • Patients without a definitive diagnosis of CML

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Busulfan?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Busulfan?”


  • Bone marrow depression may occur
  • Seizures reported with use; initiate anticonvulsant prophylactic therapy before treatment with busulfan; monitor patients with a history of seizure disorder, head trauma, or receiving epileptogenic drugs
  • Cardiac tamponade reported in children with thalassemia in combination with cyclophosphamide
  • Ovarian failure may occur
  • Secondary malignancies reported
  • Antiemetics may be recommended to prevent nausea and vomiting
  • Increased risk of developing the hepatic veno-occlusive disease (HVOD) at AUC greater than 1,500 μM•min; monitor serum transaminases, alkaline phosphatase, and bilirubin daily
  • Bronchopulmonary dysplasia with pulmonary fibrosis reported and can be fatal; toxicity may be additive if used with other agents that cause pulmonary toxicity; discontinue therapy if busulfan toxicity develops
  • Avoid pregnancy; can cause fetal harm; advise of the potential risk to a fetus and use effective contraception

Pregnancy & Lactation

  • Can cause fetal harm when administered to a pregnant woman based on animal data; the drug has shown to be teratogenic in mice, rats, and rabbits following administration during organogenesis; the solvent, DMA, may also cause fetal harm when administered to a pregnant woman; in rats, DMA doses of approximately 40% of the daily dose of DMA in dose on an mg/m² basis given during organogenesis caused significant developmental anomalies; no available human data are informing drug-associated risk; advise pregnant women of the potential risk to a fetus
  • Advise females of reproductive potential to use effective contraception during treatment and for 6 months following cessation of therapy
  • May damage spermatozoa and testicular tissue, resulting in possible genetic fetal abnormalities; males with female sexual partners of reproductive potential should use effective contraception during treatment and for 3 months after cessation of therapy
  • Infertility
    • Females: Ovarian suppression and amenorrhea commonly occur in premenopausal women undergoing chronic, low-dose busulfan therapy for chronic myelogenous leukemia; therapy may also cause temporary or permanent infertility in prepubertal girls or females of child-bearing potential treated with high-dose busulfan in the conditioning regimen before allogeneic hematopoietic progenitor cell transplantation
    • Males: Sterility, azoospermia, and testicular atrophy reported in male patients
  • Lactation
    • Not available


What is leukemia? See Answer

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