Purinethol-Mercaptopurine

Patient Education Quick Reference Guide Diablo Valley Oncology/Hematology Medical Group Phone Number: 925-677-5041

WARNING Mercaptopurine should not be used unless you have been diagnosed with acute lymphoblastic leukemia. Uses For This Medication
  • Mercaptopurine is used in combination with other chemotherapy medications to treat adults with acute lymphoblastic leukemia.
  • Mercaptopurine may also be used to treat adults with inflammatory diseases of the bowel, including Crohn’s disease and ulcerative colitis.
  • This medication may also be given for other conditions as determined by your doctor.
  How This Medication Works Mercaptopurine is a chemotherapy medication that doesn’t allow cancer cells, also known as tumor cells, to divide and grow normally, which leads to tumor cell death. Benefits of This Medication In patients with acute lymphoblastic leukemia, mercaptopurine is used as part of various chemotherapy treatments to help bring on remission from the disease and to help patients remain disease free. Who Should Not Take This Medication You should not take this medication if you:
  • Are allergic to mercaptopurine or any of its components.
  • Have taken thioguanine (Tabloid®) previously and your disease did not respond to it.
  Precautions to be Aware of Before Taking This Medication

Blood related precautions

  • This medication may temporarily reduce the number of platelets in your blood. This can increase your risk of bleeding. Contact your doctor or healthcare provider if you notice unusual bleeding or bruising, have black or tar-like stools, see blood in your urine, or develop pinpoint red spots on your skin. If your platelet levels become too low, your doctor or healthcare provider may recommend that your treatment be delayed, that you receive a platelet transfusion, and/or that you take medication to help increase the number of platelets in your blood. To lower your chance of bleeding, do not use aspirin, aspirin-containing medications, or aspirin-like medications (for example ibuprofen, naproxen). Use caution with sharp objects like razors and nail cutters, and avoid activities that can cause cuts, bumps and bruises. You should avoid flossing if you have been told you have low platelets.
  • This medication may temporarily reduce the number of germ fighting white blood cells in your blood. This can increase your risk of infection. Contact your doctor or healthcare provider promptly if you develop any signs of an infection such as fever, painful urination, chills or a sore throat that doesn’t go away. If your white blood cell levels become too low, your doctor or healthcare provider may recommend that your treatment be delayed and/or you receive medication to increase the number of white cells in your blood. To lower your risk of infection, stay away from crowds and people with colds or other illnesses, wash your hands well and often with soap and water, brush and floss your teeth daily.
  • This medication may temporarily lower the number of red cells in your blood. This can increase your risk of anemia. If your red blood cell level becomes low, you may feel tired and weak. If your red blood cell level becomes too low, your doctor or healthcare provider may recommend that your treatment be delayed, that you receive a red blood cell transfusion, and/or you receive a medication to help increase the red cells in your blood.
  Infection related precautions Very serious bacterial, viral, and fungal infections have been reported in patients receiving mercaptopurine. Your doctor or healthcare provider may prescribe medications to help prevent certain infections. These medications may be given at the start of mercaptopurine treatment and will be continued even after your last mercaptopurine dose. Your healthcare provider will tell you how long to take these medicines. Gastrointestinal related precautions This medication may cause nausea and/or vomiting. Eat small frequent meals and bland foods (for example bananas, rice, apples, toast). If you are having moderate or severe vomiting, tell your doctor or healthcare provider. Nausea and vomiting can be treated with medications. Organ related precautions This medication can cause changes in the ability of your liver to work normally. Your doctor or healthcare provider will check your liver regularly, usually through blood tests, while you are on this medication to make sure that your liver is working properly. If you have any liver problems before starting this medication, make sure that you tell your doctor or healthcare provider so that he or she can watch you carefully for possible problems or side effects. Miscellaneous precautions
  • Some patients may have an inherited deficiency of the enzyme called thiopurine methyltransferase (TPMT). Patients who have this enzyme deficiency may be more sensitive to the blood related side effects of mercaptopurine. Your doctor or healthcare provider may perform blood tests prior to starting mercaptopurine to determine if you have this enzyme deficiency. The development of additional, or secondary, cancers has been reported in patients receiving mercaptopurine.
  • Do not receive any immunizations (vaccinations) while on this medication without your doctor or healthcare provider’s approval. This medication can increase your risk of infection. For certain immunizations, you may develop the infection that the immunization is intended to prevent.
 

Patient specific precautions

  • This medication is safe and effective in the treatment of children. Like adults, children can have liver related problems from this medication.
  Pregnancy and Breastfeeding Precautions This medication can cause fetal harm. When taking this medication, you should use effective birth control to prevent pregnancy. Tell your doctor or healthcare provider right away if you or your spouse/partner becomes pregnant. It is not known whether this medication is found or excreted in breast milk. Since many medications are excreted in breast milk and because this medication can cause serious harmful reactions in infants, breastfeeding should be avoided. Many anti-cancer therapies can cause sterility. Notify your doctor or healthcare provider if you want to have children in the future. Medication and Food Interactions Before using this medication, tell your doctor or healthcare provider of all prescription or over-the- counter products you are taking, including dietary supplements or vitamins, herbal medicines and homeopathic remedies. Do not start or stop any medication without your doctor or healthcare provider’s approval. Possible interactions can occur with mercaptopurine and the following medications:
  • Allopurinol
  • Azathioprine
  • Balsalazide
  • Doxorubicin
  • Olsalazine (Dipentum®)
  • Mesalazine
  • Mesalamine
  • Methotrexate
  • Sulfamethoxazole/Trimethoprim(Septra®)
  • Sulfasalazine (Azulfidine®)
  • Warfarin (Coumadin)
  NOTE: This list may not include all medications that can have interactions with mercaptopurine. Side Effects
  • All medications can cause side effects. However, not all patients will experience these side effects. In addition, other side effects not listed can also occur in some patients. You should call your doctor or healthcare provider if you have any questions or concerns while you are on this medication.
  • You should contact your doctor or healthcare provider if you experience any side effect(s) which don’t go away, worsen, are serious in nature, or are worrisome to you.
  • Side effects can occur when mercaptopurine is given alone or together with other chemotherapy medications. The side effects listed below are those reported in patients who were treated with mercaptopurine alone.
 

More common side effects

  • Decreased platelet, red blood cell, and/or white blood cell levels (see Precautions To Be Aware Of Before Taking This Medication)
  • High uric acid levels
  • Less common side effects
  • Nausea, vomiting, loss of appetite
  • Diarrhea
 

Rare side effects

This is not a complete list of the rare side effects reported with mercaptopurine. For a complete list, please talk with your doctor or healthcare provider about reviewing a copy of the package insert.
  • Liver problems (see Precautions To Be Aware Of Before Taking This Medication)
  • Skin rashes, hyperpigmentation (darkening) of the skin
  • Hair loss
  • Drug fever
  • Mouth sores
  How To Take This Medication
  • This medication is taken by mouth (orally). Take this medication exactly as directed by your doctor or healthcare provider. If you do not understand these instructions, ask your doctor or healthcare provider to explain them to you. This medication can be given in different doses depending on your weight and the type of condition being treated.
  • It is important that you only use this medication when it’s been prescribed for you. Sharing this medication with someone for whom it is not prescribed could cause harm.
  • If you accidentally take too many pills or someone else accidentally takes your medication, contact your doctor, your local poison control center at 1-800-222-1222, or emergency services immediately.
 

Proper Storage

  • Store this medication at controlled room temperature.
  • Keep this medication out of the reach of children or pets.
  • Ask your doctor or healthcare provider how to dispose of any medication that you no longer use.