Pentostatin is used to treat hairy cell leukemia (a type of blood cancer).

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

Pentostatin can cause harmful side effects on your kidneys, liver, lungs, or central nervous system. Call your doctor at once if you have symptoms such as: swelling, rapid weight gain, little or no urinating, pink or red urine, severe shortness of breath, wheezing, chest pain, cough, vision problems, numbness, tingling, or burning pain.

Your doctor will perform blood tests to make sure you do not have conditions that would prevent you from safely receiving pentostatin.

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

Pentostatin is usually given every other week. Your doctor will determine how long to treat you with pentostatin.

Pentostatin can lower your blood cell counts. Your blood will need to be tested often. Your cancer treatments may be delayed based on the results. You may also need to have a bone marrow biopsy.

Usual Adult Dose for Hairy Cell Leukemia:

4 mg/m2 IV by bolus injection OR diluted in a larger volume and given over 20 to 30 minutes every other week (higher doses are not recommended)

Duration of therapy: In the absence of major toxicity and with continuing improvement, treat until complete response; although not required, the administration of 2 additional doses has been recommended following complete response.

Comments:
-Patients should be hydrated with 500 to 1000 mL of 5% dextrose in 0.5 normal saline or equivalent before this drug is administered; an additional 500 mL should be administered after this drug is given.
-Assess response to therapy after 6 months.
-Continue therapy if patient achieves at least a partial response after 6 months.
-Discontinue therapy if patient has not achieved at least a partial response after 6 months.
-Discontinue therapy if patient has only a partial response after 12 months.
-Withhold therapy in patients with active infection until the infection is controlled.

Use: A single-agent treatment for both untreated and alpha-interferon-refractory hairy cell leukemia patients with active disease as defined by clinically significant anemia, neutropenia, thrombocytopenia, or disease-related symptoms

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

Tell your doctor if you have ever had:

• kidney disease;

• liver disease;

• lung disease;

• any type of infection (including pneumonia); or

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

Pentostatin 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 pentostatin.

Call your doctor for instructions if you miss an appointment for your pentostatin injection.

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

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

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

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

• skin sores, severe skin rash;

• confusion, hallucinations, problems with speech or memory, seizure;

• muscle twitching, loss of movement in any part of your body;

• numbness, tingling, or burning pain;

• fluid build-up in or around the lungs--pain when you breathe, feeling short of breath while lying down, wheezing, gasping for breath, cough with foamy mucus, cold, clammy skin, anxiety, rapid heartbeats;

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

• 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.

Common side effects of pentostatin may include:

• loss of appetite, nausea, vomiting, stomach pain;

• diarrhea;

• rash, itching;

• muscle pain;

• headache, tiredness; or

• fever, chills, cough.

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.

Tell your doctor about all your other medicines, especially:

• carmustine;

• cyclophosphamide;

• etoposide;

• fludarabine; or

• vidarabine.

This list is not complete. Other drugs may affect pentostatin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.