Chemotherapy (chemo) uses strong medicines to kill cancer cells. The medicines affect and kill cancer cells that grow quickly. Some normal cells also grow quickly. Because of this, chemo can also harm those cells. This can cause side effects.

For chronic lymphocytic leukemia (CLL), chemo may be one of the first treatments used. Your doctor may suggest chemo if you start to have symptoms or signs that your leukemia is getting worse (such as blood counts getting worse).

Chemo won't cure CLL. But it can often help keep it under control. Even if the leukemia is very advanced, chemo may help ease symptoms. This can help you feel better and improve your quality of life.

Most people get chemo in an outpatient part of the hospital, at a doctor's office, or at an infusion clinic. Some people may need to stay in the hospital during treatment. This depends on the medicines you are given and your overall health.

You may get chemo in pill form, by injection, or through a small, flexible tube that's put into a vein by I.V. (intravenously). You may get chemo in more than one way.

You get chemo in cycles over a period of time. This means you take the medicine for a set amount of time and then you have a rest period. Each period of treatment and rest is one cycle. You'll likely get several cycles. Having treatment in cycles helps by:

• Killing more cancer cells. Chemo can kill more cancer cells over time because the cells aren't all dividing at the same time. Cycles allow the chemo to fight more cells.
• Giving your body a rest. Treatment is hard on other cells of the body that divide quickly. This includes cells in the lining of the mouth and stomach. It causes side effects such as mouth sores and nausea. Chemo can also cause a drop in healthy blood cells. Between cycles your body can get a rest and healthy cells can recover.
• Giving your mind a rest. Chemo can be stressful. Taking breaks between cycles can let you get an emotional break between treatments.

The chemo medicines used most often for CLL include:

• Fludarabine.
• Chlorambucil.
• Cyclophosphamide.
• Bendamustine.

You may get one medicine at a time, or a combination of medicines. Chemo is often combined with other medicines, such as targeted therapy or immunotherapy.

The medicines you get and how often you get them will depend on many factors. They include your overall health, the genetic changes in your CLL cells, and your age. For instance, if you're older or have other major health problems, you may be given a chemo medicine that tends to cause fewer side effects.

Your doctor may also give you medicines called steroids, such as prednisone, methylpredisolone, or dexamethasone. This is done to help fight a problem of CLL in which the immune system attacks the body's healthy blood cells.

Chemo medicines affect and kill cells that divide quickly, such as cancer cells. They can also affect normal cells that divide quickly. These include hair follicles, the lining of the intestines and mouth, and the bone marrow cells where new blood cells are made. The side effects of chemo are different for everyone. They often go away over time when treatment ends.

The most common short-term side effects of chemo include:

• Loss of appetite.
• Easy bruising or bleeding from low levels of blood platelets.
• Diarrhea.
• Severe tiredness (fatigue) from having low levels of red blood cells (anemia).
• Hair loss.
• Headaches.
• Increased chance of infections from low levels of white blood cells.
• Loss of sexual desire.
• Mouth sores.
• Nausea and vomiting.
• Pain when swallowing.

Tumor lysis syndrome is another possible side effect of chemo. It tends to happen during the first cycle if you have a very high number of CLL cells in your blood (sometimes called bulky disease). The chemo kills the cells and all the cell waste is dumped into your blood. Your kidneys can't filter it out fast enough. This can lead to serious problems like kidney failure and heart rhythm changes. To keep this from happening, you might get extra fluid in your I.V. to help wash the cell waste through your kidneys. If your risk for tumor lysis syndrome is high, certain medicines can also be used to help prevent it.

It's important to know which medicines you're taking. Write down the names of your medicines. Ask your health care team how they work, what they do, and what side effects they might cause.

Talk with your doctor about what signs to look for, and when you should call. Make sure you know what number to call with questions, even after office hours, on holidays, and weekends.

It may be helpful to keep a diary of your side effects. Write down any physical, thinking, and emotional changes. A written list will make it easier for you to remember your questions when you go to your appointments. It will also make it easier for you to work with your health care team to make a plan to manage your side effects.