Mercaptopurine is a prescription medication that is used to treat acute lymphoblastic or lymphocytic leukemia. Mercaptopurine may be prescribed to be taken alone or with other cancer medications. This medication is a chemotherapy drug and works by slowing or stopping the growth of cancer cells.

Make sure to always read the patient information and instructions before using this medication. Always follow your doctor’s directions.

• Mercaptopurine may be taken with or without food.
• Drink plenty of fluids while taking this medication to keep your kidneys working properly.
• Take this medication at the same time every day when possible.

Tell your doctor and pharmacist:

• About your drug and other allergies.
• If you take any other prescription or over-the-counter medications.
• If you have ever used mercaptopurine or thioguanine and they were not effective.
• Your medical history particularly of liver disease, kidney disease, ulcerative colitis, thiopurine methyltransferase or any viral, bacterial, or fungal infection,

You should also know:

• Use effective birth control while taking mercaptopurine. This medication may harm an unborn baby, especially during the first trimester. Speak to your doctor if you become pregnant.
• You should not breast-feed while taking this medication.
• Some people who have taken this medication have developed lymphoma. Speak to your doctor for more information.
• This medication can weaken the immune system. Avoid people that are sick or have infections and speak to your doctor if you show signs of an infection.
• Do not receive any live vaccines while taking this medication as they may not be as effective.

Common side effects of mercaptopurine include but are not limited to:

• Nausea or vomiting.
• General ill-feeling.
• Diarrhea.
• Unusual or easy bruising or bleeding.
• Low blood cell counts.
• Changes to your skin color or rashes.
• Loss of appetite.
• Hair loss.

Get medical help if you have any of the following side effects of mercaptopurine:

• Signs of a low blood cell count including shortness of breath, lightheadedness, unusual bleeding, cold hands and feet, easy bruising, fever, chills, tiredness, skin sores, or mouth sores.
• Signs of a liver problem such as dark urine, clay-colored stools, jaundice, nausea, vomiting, loss of appetite, upper stomach pain, diarrhea, or swelling in the midsection.
• Signs of lymphoma such as feeling full, weight loss, fever, tiredness, stomach bloating, feeling full, or night sweats.
• Symptoms of an allergic reaction such as difficulty breathing, hives, or swelling in your face, lips, or throat.

What is the strength of mercaptopurine?

Mercaptopurine is available in a strength of 50mg.

Can I take mercaptopurine while pregnant?

No. Use effective birth control while taking this medication.