Busulfan oral (taken by mouth) is used to treat the symptoms of chronic myelogenous leukemia (a type of blood cancer). Busulfan is not a cure for leukemia.

Busulfan injection is used together with a medicine called cyclophosphamide, to prepare your body to receive a stem cell transplant from a donor's bone marrow.

Busulfan may also be used for purposes not listed in this medication guide.

You should not use busulfan if you are allergic to it.

Tell your doctor if you have ever had:

• a weak immune system (bone marrow depression) caused by other cancer medications or radiation treatment;
• epilepsy or other seizure disorder;
• a head injury; or
• lung or breathing problems.

Some people treated with busulfan have developed new forms of cancer. Talk to your doctor about your specific risks and benefits of using this medicine.

Busulfan can harm an unborn baby or cause birth defects if the mother or the father is using this medicine.

• If you are a woman, do not use busulfan if you are pregnant. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 6 months after your last dose.
• If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 3 months after your last dose.
• Tell your doctor right away if a pregnancy occurs while either the mother or the father is using busulfan.

High-dose busulfan may affect fertility (ability to have children) in women, either temporarily or permanently. Talk with your doctor if you have concerns about this risk.

You should not breastfeed while using this medicine.

Use Busulfan (Oral/Injection)(Intravenous,Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Call your doctor at once if you have:

• easy bruising, unusual bleeding, purple or red spots under your skin;
• fever, chills, tiredness, sore throat;
• cough, trouble breathing, chest pain, wheezing;
• coughing with bloody mucus;
• pale skin, cold hands and feet;
• vision problems;
• persistent cough, congestion, or breathing problems that occur several months or years after using busulfan;
• a seizure;
• adrenal gland problems--nausea, vomiting, loss of appetite, weight loss and severe weakness or tired feeling;
• signs of a heart problem--stomach pain, vomiting, sharp chest pain, trouble breathing;
• signs of liver problems--weight gain, stomach swelling or tenderness, jaundice (yellowing of the skin or eyes); o
• signs of an electrolyte imbalance--muscle contractions, muscle weakness, leg cramps, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling.

Common side effects may include:

• fever, chills, headache, weakness;
• pain;
• nausea, vomiting, stomach pain, diarrhea;
• fast heartbeats;
• changes in your menstrual periods;
• blisters or ulcers in your mouth, red or swollen gums, trouble swallowing;
• dry mouth, nose, or throat;
• dry or thinning skin, darkened skin color;
• breast swelling;
• sleep problems (insomnia); or
• anxiety.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.