Mercaptopurine

Where is Mercaptopurine used?

Mercaptopurine is a chemotherapy drug used for the treatment of a certain type of cancer such as:

  • Acute myelogenous leukemia (AML)
  • Chronic myeloid leukemia (CML)

Chemotherapy is most effective at killing cells that are rapidly dividing. This medication is classified as an antimetabolite that damages the DNA or RNA that tells the cell how to copy itself in the division. If the cells are unable to divide, they die.

Mercaptopurine is a prescription approved by the Food and Drug Administration (FDA). This is available in tablet form for oral use.

How does Mercaptopurine work?

The bone marrow creates cells called stem cells. These usually develop into different types of blood cells. When these are mature they leave the bone marrow and enter the bloodstream. In leukemia, the bone marrow produces too many immature white blood cells. These abnormal cells take up space in the bone marrow and result in less room for the production of normal healthy blood cells.

Mercaptopurine stops the abnormal blood cells from increasing by being joined into the genetic material of the cells, RNA, and DNA. Both RNA and DNA are needed for cells to grow and repair themselves then multiply. This drug causes problems with the production of RNA and DNA in cancer cells. It causes the cells to grow in an unbalanced way, resulting in the death of the cells. Mercaptopurine usually takes between 6 weeks and 3 months to become fully effective. During that time, you may need to take corticosteroids to maintain control of your disease.

How is Mercaptopurine taken?

Mercaptopurine is to be taken by mouth usually once a day or as directed by your doctor. You may take each dose with or without a meal. Swallow the tablet as a whole with a full glass of water. Do not break, chew, or crush it.

Drink plenty of fluids while having this treatment. Doing so may lessen the risk of certain side effects. If you missed a dose, call your doctor. Do not double the dose to make up for the missed dose. Let your doctor know if your condition does not improve or if it gets worse.

What are the possible side effects of Mercaptopurine?

Common side effects:

  • Vomiting
  • Nausea
  • Loss of appetite
  • Diarrhea
  • Darkened skin color
  • Itching or skin rash
  • Temporary hair loss

Tell your doctor if you have these unlikely but serious side effects of Mercaptopurine such as:

  • Dizziness
  • Easy bruising or bleeding
  • Joint pain or swelling
  • Fainting
  • Unusual tiredness
  • Tongue or mouth sores or pain

What are the precautions in taking Mercaptopurine?

  • This should not be used in breastfeeding women.
  • This is not recommended for use if you are allergic to any of its ingredients. Let your doctor know if you have previously experienced such an allergy.
  • The drug may be harmful to a developing baby. This should not be used during pregnancy unless it is recommended by your doctor.
  • Do not have vaccinations or immunizations while having this treatment without the consent of your doctor.
  • Inform your doctor if you have a medical history of liver disease, kidney disease, or certain enzyme disorder.
  • Avoid contact with people who have infections that may spread to others. Consult your doctor if you have been exposed to an infection.