Leustatin is a cancer medicine that is used to treat hairy cell leukemia (a type of blood cancer).

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

Leustatin can increase your risk of bleeding or infection. Call your doctor if you have unusual bruising or bleeding, or new signs of infection (fever, chills, cough, chest pain, mouth sores, skin sores, sore throat, trouble breathing).

Very high doses of cladribine injection can cause nerve damage or paralysis that may not be reversible. However, this effect is rare when Leustatin is given in recommended doses.

Leustatin is given as an infusion into a vein. A healthcare provider will give you this injection.

Leustatin is usually given around the clock for 7 days in a row. Your doctor will determine how many 7- day treatments you will receive and how often.

Leustatin can increase your risk of bleeding or infection. You will need frequent medical tests, and your next dose may be delayed based on the results.

If Leustatin accidentally gets on your skin, wash it thoroughly with soap and warm water.

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

Tell your doctor if you have ever had:

• heart problems;

• liver or kidney disease; or

• weak immune system (caused by disease or by using certain medicine).

Leustatin may harm an unborn baby. Use effective birth control to prevent pregnancy, and tell your doctor if you become pregnant.

You should not breastfeed while using Leustatin.

Since this medication is given in a healthcare setting around the clock, you will not miss a dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Very high doses of Leustatin can cause nerve damage. In some people, this has resulted in loss of movement (paralysis) that may not be reversible. However, such severe symptoms are rare when Leustatin is given in recommended doses. Talk with your doctor if you have concerns about this risk.

Do not receive a "live" vaccine while using Leustatin, or you could develop a serious infection. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

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

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Leustatin may cause serious side effects. Call your doctor at once if you have:

• numbness, tingling, weakness, or burning pain in your fingers or toes;

• loss of movement in any part of your body;

• redness, swelling, or itching under your skin;

• low blood cell counts--fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath;

• kidney problems--little or no urination, swelling in your feet or ankles, feeling tired or short of breath;

• signs of infection--fever, chills, cough, chest pain, mouth sores, skin sores, sore throat, trouble breathing; or

• signs of tumor cell breakdown--tiredness, weakness, muscle cramps, nausea, vomiting, diarrhea, fast or slow heart rate, tingling in your hands and feet or around your mouth.

Common side effects of Leustatin may include:

• fever;

• nausea, vomiting, diarrhea;

• headache, tiredness;

• rash;

• cough; or

• pain, bruising, swelling, or irritation where the medicine was injected.

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.

Leustatin can harm your kidneys, especially if you also use certain medicines for infections, cancer, osteoporosis, organ transplant rejection, bowel disorders, high blood pressure, or pain or arthritis (including Advil, Motrin, and Aleve).

Other drugs may affect Leustatin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.