Mercaptopurine Tablets

What is this medication?

MERCAPTOPURINE (mer kap toe PYOOR een) treats leukemia. It works by slowing down the growth of cancer cells.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Purinethol

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

• Kidney disease
• Liver disease
• Low blood cell levels (white cells, red blood cells, and platelets)
• Nucleotide diphosphatase (NUDT15) deficiency
• Recent or upcoming vaccine
• Thiopurine methyltransferase (TPMT) deficiency
• An unusual or allergic reaction to mercaptopurine, other medications, foods, dyes, or preservatives
• If you or your partner are pregnant or trying to get pregnant
• Breast-feeding

How should I use this medication?

Take this medication by mouth with a glass of water. Take it as directed on the prescription label at the same time every day. Keep taking it unless your care team tells you to stop.

Talk to your care team about the use of this medication in children. While it may be prescribed for children for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, skip it. Take your next dose at the normal time. Do not take extra or 2 doses at the same time to make up for the missed dose.

What may interact with this medication?

Do not take this medication with any of the following:

• Azathioprine
• Febuxostat
• Live virus vaccines

This medication may also interact with the following:

• Allopurinol
• Certain medications that treat or prevent blood clots, such as warfarin
• Certain medications that treat ulcerative colitis, such as balsalazide, olsalazine, mesalamine, sulfasalazine
• Trimethoprim; sulfamethoxazole

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Your condition will be monitored carefully while you are receiving this medication.

This medication may make you feel generally unwell. This is not uncommon as chemotherapy can affect healthy cells as well as cancer cells. Report any side effects. Continue your course of treatment even though you feel ill unless your care team tells you to stop.

This medication may increase your risk to bruise or bleed. Call your care team if you notice any unusual bleeding.

This medication may increase your risk of getting an infection. Call your care team for advice if you get a fever, chills, sore throat, or other symptoms of a cold or flu. Do not treat yourself. Try to avoid being around people who are sick.

This medication can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps, tanning beds, or tanning booths.

Talk to your care team about your risk of cancer. You may be more at risk for certain types of cancers if you take this medication.

Talk to your care team if you or your partner are pregnant or think either of you might be pregnant. This medication can cause serious birth defects if taken during pregnancy or for 6 months after the last dose. A negative pregnancy test is required before starting this medication. A reliable form of contraception is recommended while taking this medication and for 6 months after the last dose. Talk to your care team about reliable forms of contraception. Do not father a child while taking this medication and for 3 months after the last dose. Use a condom while having sex during this time period.

Do not breast-feed while taking this medication or for 1 week after the last dose.

This medication may cause infertility. Talk to your care team if you are concerned about your fertility.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

• Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
• Infection—fever, chills, cough, sore throat, wounds that don't heal, pain or trouble when passing urine, general feeling of discomfort or being unwell
• Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
• Low red blood cell level—unusual weakness or fatigue, dizziness, headache, trouble breathing
• Unusual bruising or bleeding

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

• Diarrhea
• General discomfort and fatigue
• Loss of appetite
• Nausea
• Vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from moisture. Keep container tightly closed. Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

• Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
• If you cannot return the medication, ask your pharmacist or care team how to get rid of this mediation safely.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.