In the U.S.—

In Canada—

Other commonly used names are 2'-deoxycoformycin; 2'DCF.

• Antineoplastic

Pentostatin ( PEN-toe-stat-in) belongs to the group of medicines called antimetabolites. It is used to treat hairy cell leukemia.

Pentostatin interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal body cells may also be affected by pentostatin, other effects will also occur. Some of these may be serious and must be reported to your doctor. Other effects may not be serious but may cause concern. Some effects may not occur for months or years after the medicine is used.

Before you begin treatment with pentostatin, you and your doctor should talk about the good this medicine will do as well as the risks of using it.

Pentostatin is to be administered only by or under the immediate supervision of your doctor. It is available in the following dosage form:

Parenteral
• Injection (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For pentostatin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to pentostatin.

Pregnancy—There is a chance that this medicine may cause birth defects if either the male or female is taking it at the time of conception or if it is taken during pregnancy. Pentostatin has been shown to cause birth defects in rats and mice. In addition, many cancer medicines may cause sterility which could be permanent. Although sterility has not been reported with this medicine, it does occur in animals and the possibility should be kept in mind.

Be sure that you have discussed this with your doctor before taking this medicine. It is best to use some kind of birth control while you are receiving pentostatin. Tell your doctor right away if you think you have become pregnant while receiving pentostatin.

Breast-feeding—It is not known whether pentostatin passes into breast milk. However, because this medicine may cause serious side effects, breast-feeding is generally not recommended while you are receiving it.

Children—There is no specific information comparing use of pentostatin in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of pentostatin in the elderly with use in other adults, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving pentostatin, it is especially important that your health care professional know if you are taking any of the following:

• Amphotericin B by injection (e.g., Fungizone) or
• Antithyroid agents (medicine for overactive thyroid) or
• Azathioprine (e.g., Imuran) or
• Chloramphenicol (e.g., Chloromycetin) or
• Colchicine or
• Flucytosine (e.g., Ancobon) or
• Ganciclovir (e.g., Cytovene) or
• Interferon (e.g., Intron A, Roferon-A) or
• Plicamycin (e.g., Mithracin) or
• Zidovudine (e.g., AZT, Retrovir) or
• If you have ever been treated with x-rays or cancer medicines—Pentostatin may increase the effects of these medicines or radiation therapy on the blood

• Probenecid (e.g., Benemid) or
• Sulfinpyrazone (e.g., Anturane)—Pentostatin may raise the amount of uric acid in the blood. Since these medicines are used to lower uric acid levels, they may not be as effective in patients receiving pentostatin

• Chickenpox (including recent exposure) or
• Herpes zoster (shingles)—Risk of severe disease affecting other parts of the body

• Gout (history of) or
• Kidney stones (history of)—Pentostatin may increase levels of uric acid in the body, which can cause gout or kidney stones

• Infection—Pentostatin may decrease your body's ability to fight infection

• Kidney disease—Effects of pentostatin may be increased because of slower removal from the body

This medicine often causes nausea and vomiting. However, it is very important that you continue to receive the medicine even if you begin to feel ill. Ask your health care professional for ways to lessen these effects.

Dosing—

The dose of pentostatin will be different for different patients. The dose that is used may depend on a number of things, including what the medicine is being used for, the patient's size, and whether or not other medicines are also being taken. If you are receiving pentostatin at home, follow your doctor's orders or the directions on the label. If you have any questions about the proper dose of pentostatin, ask your doctor.

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

While you are being treated with pentostatin, and after you stop treatment with it, do not have any immunizations (vaccinations) without your doctor's approval. Pentostatin may lower your body's resistance and there is a chance you might get the infection the immunization is meant to prevent. In addition, other persons living in your household should not take oral polio vaccine since there is a chance they could pass the polio virus on to you. Also, avoid persons who have taken oral polio vaccine. Do not get close to them and do not stay in the same room with them for very long. If you cannot take these precautions, you should consider wearing a protective face mask that covers the nose and mouth.

Pentostatin can lower the number of white blood cells in your blood temporarily, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
• Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in urine or stools; or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.

Along with its needed effects, a medicine may cause some unwanted effects. Some side effects will have signs or symptoms that you can see or feel. Your doctor may watch for others by doing certain tests.

Also, because of the way these medicines act on the body, there is a chance that they might cause other unwanted effects that may not occur until months or years after the medicine is used. These delayed effects may include certain types of cancer. Discuss these possible effects with your doctor.

Check with your doctor or nurse immediately if any of the following side effects occur:

• More common
  • Cough or hoarseness;  fever or chills ;  lower back or side pain;  painful or difficult urination 
  
  

• Less common
  • Black, tarry stools;  blood in urine or stools;  chest pain;  pinpoint red spots on skin;  unusual bleeding or bruising  
  
  

Check with your health care professional as soon as possible if any of the following side effects occur:

• More common
  • Pain;  skin rash or itching (sudden) ;  unusual tiredness 
  
  

• Less common
  • Anxiety or nervousness;  changes in vision ;  confusion;  cramps in lower legs;  mental depression;  nosebleed;  numbness or tingling of hands or feet ;  shortness of breath;  sleepiness;  sore, red eyes;  sores in mouth or on lips;  stomach pain;  swelling of feet or lower legs;  trouble in sleeping 
  
  

This medicine may also cause the following side effects that your doctor will watch for:

• More common
  • Anemia;  liver problems;  low platelet counts 
  
  

• Less common
  • Kidney problems 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• More common
  • Diarrhea;  headache;  loss of appetite;  muscle pain;  nausea and vomiting;  skin rash 
  
  

• Less common
  • Back pain;  bloating or gas;  constipation;  dry skin;  general feeling of discomfort or illness;  itching;  joint pain;  weakness ;  weight loss 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, pentostatin is used in certain patients with the following medical conditions:

• Cancers of the blood
• Cancers of the lymph system (a part of the body's immune system), including a type that affects the skin

Other than the above information, there is no additional information relating to proper use, precautions, or side effects for these uses.