Generic name: Busulfan
Other trade name: Myleran^®

Chemocare.com uses generic names in all descriptions of drugs. Busulfex is a trade name for Busulfan. Myleran is another trade name for Busulfan. In some cases, health care professionals may use the trade names Busulfex or Myleran when referring to the generic drug name Busulfan.

Drug type: Busulfex is an anti-cancer ("antineoplastic" or "cytotoxic") chemotherapy drug.  Busulfex is classified as an "alkylating agent."  (For more detail, see "How this drug works" section below).

What This Drug Is Used For:

• Busulfan is used to treat chronic myelogenous leukemia (CML). 
• Also used to treat certain blood disorders such as polycythemia vera and myeloid metaplasia.
• Used in some conditioning regimens prior to bone marrow transplant.
  Note:  If a drug has been approved for one use, physicians sometimes elect to use this same drug for other problems if they believe it might be helpful.

How This Drug Is Given:

• Busulfan is taken by mouth in pill form.
• It also may be given as an infusion into the vein (intravenous or IV).
• The amount of busulfan that you will receive and how it is given depends on many factors, including your height and weight, your general health or other health problems, and the type of cancer or condition being treated. 
• Your doctor will determine your dose and schedule.

Side Effects:

Important things to remember about the side effects of busulfan:

• Most people do not experience all of the side effects listed.
• Side effects are often predictable in terms of their onset and duration.
• Side effects are almost always reversible and will go away after treatment is complete.
• There are many options to help minimize or prevent side effects.
• There is no relationship between the presence or severity of side effects and the effectiveness of the medication.

The following side effects are common (occurring in greater than 30%) for patients taking busulfan:

• Low blood counts. Your white and red blood cells and platelets may temporarily decrease.  This can put you at increased risk for infection, anemia and/or bleeding.  In rare cases this can also be a delayed effect.

Nadir: Meaning low point, nadir is the point in time between chemotherapy cycles in which you experience low blood counts.

Onset: 7-10 days
Nadir: 14-21 days
Recovery: 28 days

• Nausea and vomiting (usually mild with standard doses).
• Diarrhea (usually mild with standard doses).
• Poor appetite.
• Mouth sores.
• Loss of fertility.  Meaning, your ability to conceive or father a child may be affected by busulfan.  This effect is dose dependent.  Discuss this issue with your health care provider.

These side effects are less common side effects (occurring in about 10-29%) of patients receiving busulfan:

• Discoloration of the skin, especially in the creases of the hands and nail beds.
• Skin rash
• Itching

These are rare but serious complications of busulfan therapy:

• Lung problems. After long-term or high-dose therapy a syndrome known as "busulfan lung" may occur.  This may be a delayed toxicity occurring 1 to 10 years after discontinuation of treatment.  Symptoms include cough, shortness of breath and fever.
• Liver problems, seen with high dose therapy such as used in bone marrow transplant setting (syndrome consists of enlarged liver, jaundice, ascites and liver failure).
• Adrenal insufficiency (low production of needed steroids produced by the adrenal glands). Symptoms of adrenal insufficiency are:
• Fatigue, poor appetite, nausea, vomiting, diarrhea, weight loss, weakness, and dizziness.  Be sure your health care provider is aware if you are experiencing these symptoms.  If adrenal insufficiency occurs replacement steroids may be needed.
• Seizures may occur with high doses used in bone marrow transplant.  Anti-seizure medications are often used to prevent this.
• Increased risk of secondary cancer such as acute leukemia especially with long-term use of the drug.  Discuss this with your doctor.

Not all side effects are listed above, some that are rare (occurring in less than 10% of patients) are not listed here.  However, you should always inform your health care provider if you experience any unusual symptoms.

When to contact your doctor or health care provider:

Contact your health care provider immediately, day or night, if you should experience any of the following symptoms:

• Fever of 100.4° F (38° C) or higher, chills (possible signs of infection).

The following symptoms require medical attention, but are not an emergency.  Contact your health care provider within 24 hours of noticing any of the following:

• Nausea (interferes with ability to eat and unrelieved with prescribed medication).
• Vomiting (vomiting more than 4-5 times in a 24 hour period).
• Diarrhea (4-6 episodes in a 24-hour period).
• Unusual bleeding or bruising
• Black or tarry stools, or blood in your stools
• Blood in the urine
• Pain or burning with urination
• Extreme fatigue (unable to carry on self-care activities)
• Dizziness
• Mouth sores (painful redness, swelling or ulcers)
• Yellowing of the skin or eyes
• Swelling of the abdomen

Always inform your health care provider if you experience any unusual symptoms.

Precautions:

• Before starting busulfan treatment, make sure you tell your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc.
• Do not take aspirin, products containing aspirin unless your doctor specifically permits this.
• Do not receive any kind of immunization or vaccination without your doctor's approval while taking busulfan.
• Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment. Pregnancy category D (Busulfan may be hazardous to the fetus.  Women who are pregnant or become pregnant must be advised of the potential hazard to the fetus).
• For both men and women: Do not conceive a child (get pregnant) while taking busulfan. Barrier methods of contraception, such as condoms, are recommended. Discuss with your doctor when you may safely become pregnant or conceive a child after therapy.
• Do not breast feed while taking this medication.

Self-Care Tips:

• Take pills by mouth with chilled liquids.
• Drink at least two to three quarts of fluid every 24 hours, unless you are instructed otherwise.
• You may be at risk of infection so try to avoid crowds or people with colds, and report fever or any other signs of infection immediately to your health care provider.
• Wash your hands often.
• To help treat/prevent mouth sores, use a soft toothbrush, and rinse three times a day with 1/2 to 1 teaspoon of baking soda and/or 1/2 to 1 teaspoon of salt mixed with 8 ounces of water.
• Use an electric razor and a soft toothbrush to minimize bleeding.
• Avoid contact sports or activities that could cause injury.
• To reduce nausea, take anti-nausea medications as prescribed by your doctor, and eat small, frequent meals.  
• Avoid sun exposure.  Wear SPF 15 (or higher) sunblock and protective clothing.
• In general, drinking alcoholic beverages should be kept to a minimum or avoided completely.  You should discuss this with your doctor.
• Get plenty of rest. 
• Maintain good nutrition.
• If you experience symptoms or side effects, be sure to discuss them with your health care team.  They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

Monitoring and Testing:

You will be checked regularly by your health care professional while you are taking busulfan, to monitor side effects and check your response to therapy.  Periodic blood work to monitor your complete blood count (CBC) as well as the function of other organs (such as your kidneys and liver) will also be ordered by your doctor.   

How This Drug Works:

Cancerous tumors are characterized by cell division, which is no longer controlled as it is in normal tissue.   "Normal" cells stop dividing when they come into contact with like cells, a mechanism known as contact inhibition.  Cancerous cells lose this ability.  Cancer cells no longer have the normal checks and balances in place that control and limit cell division.  The process of cell division, whether normal or cancerous cells, is through the cell cycle.  The cell cycle goes from the resting phase, through active growing phases, and then to mitosis (division).

The ability of chemotherapy to kill cancer cells depends on its ability to halt cell division.  Usually, the drugs work by damaging the RNA or DNA that tells the cell how to copy itself in division.  If the cells are unable to divide, they die.  The faster the cells are dividing, the more likely it is that chemotherapy will kill the cells, causing the tumor to shrink.  They also induce cell suicide (self-death or apoptosis).

Chemotherapy drugs that affect cells only when they are dividing are called cell-cycle specific.  Chemotherapy drugs that affect cells when they are at rest are called cell-cycle non-specific.  The scheduling of chemotherapy is set based on the type of cells, rate at which they divide, and the time at which a given drug is likely to be effective.  This is why chemotherapy is typically given in cycles.

Chemotherapy is most effective at killing cells that are rapidly dividing.  Unfortunately, chemotherapy does not know the difference between the cancerous cells and the normal cells. The "normal" cells will grow back and be healthy but in the meantime, side effects occur.  The "normal" cells most commonly affected by chemotherapy are the blood cells, the cells in the mouth, stomach and bowel, and the hair follicles; resulting in low blood counts, mouth sores, nausea, diarrhea, and/or hair loss.  Different drugs may affect different parts of the body.

Busulfan is classified as an alkylating agent.  Alkylating agents are most active in the resting phase of the cell.  These drugs are cell-cycle non-specific.  There are several types of alkylating agents:

• Mustard gas derivatives:  Mechlorethamine, Cyclophosphamide, Chlorambucil, Melphalan, and Ifosfamide. 
• Ethylenimines:  Thiotepa and Hexamethylmelamine.
• Alkylsulfonates:  Busulfan.
• Hydrazines and Triazines: Altretamine, Procarbazine, Dacarbazine and Temozolomide. 
• Nitrosureas:  Carmustine, Lomustine and Streptozocin.  Nitrosureas are unique because, unlike most chemotherapy, they can cross the blood-brain barrier.  They can be useful in treating brain tumors.
• Metal salts:  Carboplatin, Cisplatin, and Oxaliplatin.

Note:  We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice.

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