Mercaptopurine Generic (Purinethol) US$ 0.75 ea

What is the most important information I should know about mercaptopurine?

Do not use mercaptopurine if you are pregnant. It could harm the unborn baby.

You should not use mercaptopurine if you are allergic to it, or if you have ever used mercaptopurine or thioguanine (Tabloid) and they were not effective in treating your condition.

Some people using mercaptopurine have developed a rare fast-growing type of lymphoma (cancer). This condition affects the liver, spleen, and bone marrow, and it can be fatal. This has occurred mainly in teenagers and young adults using mercaptopurine or similar medicines to treat Crohn's disease or ulcerative colitis.

Call your doctor at once if you have any of the following symptoms: fever, night sweats, itching, loss of appetite, weight loss, tiredness, feeling full after eating only a small amount, pain in your upper stomach that may spread to your shoulder, nausea, easy bruising or bleeding, pale skin, feeling light-headed or short of breath, rapid heart rate, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Mercaptopurine can lower blood cells that help your body fight infections. Your blood may need to be tested often. Avoid being near people who are sick or have infections. Avoid activities that may increase your risk of bleeding injury. Tell your doctor at once if you develop signs of infection.

What is mercaptopurine?

Mercaptopurine is a cancer medication that interferes with the growth and spread of cancer cells in the body.

Mercaptopurine is used to treat certain types of leukemia. Mercaptopurine is sometimes given with other cancer medications.

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

What should I discuss with my healthcare provider before taking mercaptopurine?

You should not use mercaptopurine if you are allergic to it, or if you have ever used mercaptopurine or thioguanine (Tabloid) and they were not effective in treating your condition.

Some people using mercaptopurine have developed a rare fast-growing type of lymphoma (cancer). This condition affects the liver, spleen, and bone marrow, and it can be fatal. This has occurred mainly in teenagers and young adults using mercaptopurine or similar medicines to treat Crohn's disease or ulcerative colitis.

However, people with autoimmune disorders (including rheumatoid arthritis, Crohn's disease, ankylosing spondylitis, and psoriasis) may have a higher risk of lymphoma. Talk to your doctor about your individual risk.

To make sure you can safely take mercaptopurine, tell your doctor if you have any of these other conditions:

• liver disease;
• kidney disease; or
• any type of viral, bacterial, or fungal infection.

FDA pregnancy category D. Do not use mercaptopurine if you are pregnant. It could harm the unborn baby. Use effective birth control, and tell your doctor if you become pregnant during treatment.

It is not known whether mercaptopurine passes into breast milk or if it could harm a nursing baby. You should not breast-feed while taking mercaptopurine.

How should I take mercaptopurine?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results.

Mercaptopurine can lower blood cells that help your body fight infections. Your blood cells, kidney function, and liver function may need to be tested often. Your cancer treatments may be delayed based on the results of these tests. Do not miss any follow up visits to your doctor for blood or urine tests.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

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

Overdose symptoms may include some of the serious side effects listed in this medication guide.

What should I avoid while taking mercaptopurine?

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

Avoid coming into contact with your body fluids (including urine, feces, vomit, semen, vaginal fluid). Chemotherapy can pass into body fluids. Patients or caregivers should wear rubber gloves while cleaning up body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.

Body fluids should not be handled by a woman who is pregnant or who may become pregnant. Use condoms during sexual activity to avoid exposure to body fluids.

Do not receive a "live" vaccine while using mercaptopurine. The vaccine may not work as well during this time, and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), oral polio, rotavirus, typhoid, varicella (chickenpox), H1N1 influenza, and nasal flu vaccine.

What are the possible side effects of mercaptopurine?

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

Stop using mercaptopurine and call your doctor right away if you have any of these symptoms of lymphoma:

• fever, night sweats, weight loss, tiredness;
• feeling full after eating only a small amount;
• pain in your upper stomach that may spread to your shoulder;
• easy bruising or bleeding, pale skin, feeling light-headed or short of breath, rapid heart rate; or
• nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Stop using mercaptopurine and call your doctor at once if you have any of these other serious side effects:

• signs of infection (fever, chills, sore throat, body aches, weakness, muscle pain, flu symptoms);
• severe nausea, vomiting, or diarrhea;
• bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
• pain or burning with urination; or
• white patches or sores inside your mouth or on your lips.

Less serious side effects may include:

• vomiting, mild diarrhea;
• hair loss;
• mild itching or skin rash; or
• darkened skin color.

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.

What other drugs will affect mercaptopurine?

Tell your doctor about all other cancer treatments you are receiving. Also tell your doctor about all other medicines you use, especially:

• acetaminophen;
• allopurinol;
• auranofin;
• azathioprine;
• cyclosporine;
• methotrexate;
• olsalazine, mesalamine, or sulfasalazine;
• sulfamethoxazole and trimethoprim;
• thioguanine;
• birth control pills or hormone replacement therapy;
• a blood thinner such as warfarin;
• an NSAID (non-steroidal anti-inflammatory drug) such as ibuprofen, naproxen, celecoxib, diclofenac, indomethacin, meloxicam, and others; or
• an ACE inhibitor such as benazepril, enalapril, lisinopril, quinapril, ramipril, and others;
• an antibiotic such as dapsone, erythromycin, or rifampin;
• tuberculosis medications;
• cholesterol medications such as niacin, atorvastatin, simvastatin, lovastatin, pravastatin, and others;
• HIV/AIDS medications such as abacavir/lamivudine/zidovudine, lamivudine, nevirapine, tenofovir, or zidovudine;
• antifungal medication such as fluconazole, itraconazole, or ketoconazole; or
• seizure medications such as carbamazepine, phenytoin, felbamate, valproic acid.

This list is not complete and other drugs may interact with mercaptopurine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Where can I get more information?

Your doctor or pharmacist can provide more information about mercaptopurine.