Prescription Icon Prescription Required
IMPORTANT NOTE: A valid Prescription is required to be mailed or faxed to complete this order. I acknowledge that I will need to be contacted to complete a health profile before my order is shipped.


Purinethol is an oral pill consisting of a chemotherapy drug called mercaptopurine. We carry the generic alternative of this medication in 50mg!

Purinethol is a medication used to treat a type of cancer called acute lymphocytic leukemia. This type of cancer is a type that causes the bone marrow to make too many lymphocytes, a type of white blood cells, and may also affect the red and white blood cells and platelets. Lymphocytic leukemia patients will often times have swollen lymph nodes and feel extremely tired, they may also have a fever or infection, easy bruising or bleeding, and unexplained weight loss. Although doctors aren’t exactly sure why people get lymphocytic leukemia, however, what they do know is, something unknown happens which causes a genetic mutation in the DNA of the cells that produce blood which causes the cells to produce abnormal and ineffective lymphocytes.

Purinethol (mercaptopurine) is effective at treating lymphocytic leukemia because as a chemotherapy drug it is able to affect the cancer cells in a way that forces their growth to slow down and eventually come to stop, allowing the immune system a better chance of fighting off the cancerous cells.

Follow only the directions given to you by your doctor. If you forget how your doctor would like you to take Purinethol, directions can typically be found on the prescription label. If you are still unsure on how to take this medication, contact a health care professional. Do not take more or less of a dose than prescribed. Do not stop taking this medication without first consulting your doctor.

This medication is taken by mouth with or without food, as directed by your doctor. This is most commonly done twice per day, but may vary depending on your condition, weight, and response to treatment. While taking this medication, ensure you are drinking plenty of fluids, ideally water, to keep unwanted side effects away.


Do not use Purinethol (mercaptopurine)

Do not use Purinethol if you are allergic to mercaptopurine or thioguanine, or if you used either of the two in the past and neither of them were successful in treating your condition.

Dose adjustment or special precautions may be required

Tell your doctor if you have ever had liver or kidney disease, an inherited condition in which your body cannot produce enough of the enzyme thiopurine methyltransferase (TPMT), any type of viral, bacterial, or fungal infection, or if you’re being treated for ulcerative colitis.


This medication has potential to cause a rare type of cancer of the liver, spleen, and bone marrow which can become fatal. Talk to your doctor about your risk for these complications.

Using this drug may increase your risk of developing other types of cancer as well. Your doctor should be able to help you determine your risk.

This drug may harm an unborn baby if the mother uses while pregnant, especially during the first trimester. Use effective birth control and tell your doctor if you become pregnant while using this medication.

You should not breastfeed while using this medication. Consult your doctor if this concerns you.

Side Effects

Common side effects of Purinethol (mercaptopurine) may include:

low blood cell counts; bruising or bleeding; nausea, vomiting, loss of appetite; diarrhea; rash, changes in skin color; hair loss; or general ill feeling.

The above side effects should not alarm you.

Please note this is not a complete list of side effects. Not everyone experiences side effects; they are not guaranteed. If you do have side effects and they become unmanageable, consult your doctor about alternate medications.

Contact your doctor if you notice signs of…

lymphoma: fever, night sweats, tiredness, stomach bloating, feeling full, weight loss.

liver problems: nausea, upper stomach pain, itching, tired feeling, flu-like symptoms, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

low blood cell counts: fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath.


Purinethol can cause liver damage if taken with certain medications… Which medications should I avoid while using Purinethol?

While being treated with Purinethol, to avoid increasing your chance of liver damage, do not take certain medicines for infections, tuberculosis, depression, birth control, hormone replacement, high cholesterol, heart problems, high blood pressure, seizures, pain, or arthritis (including Tylenol, Advil, Motrin, or Aleve). Do not take allopurinol, olsalazine, mesalazine, sulfasalazine or similar medicines, sulfamethoxazole and trimethoprim, or warfarin (Coumadin, Jantoven).

I have vaccine shots coming up soon. Will I need to reschedule them now that I am taking Purinethol? Will this drug affect the vaccination?

It is suggested you do not get any type of “live” vaccination while on Purinethol. The vaccination may not be as effective and may not fully protect you from the disease. Live vaccinations include vaccines for measles, mumps, rubella, polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and the nasal flu (influenza).

What are signs of an overdose on Purinethol? What do I do if I suspect an overdose?

You can recognize an overdose by noticing signs of nausea, vomiting, diarrhea, loss of appetite, following shortly after with symptoms of fever or flu-like symptoms. If this occurs and you believe an overdose is occurring; contact emergency medical services right away. You may also call the poison help line if needed or preferred.

Why do I need to drink lots of fluid during the time of treatment?

This medication can affect your kidneys and result in kidney damage. In order to avoid this adverse interaction, staying hydrated and drinking lots of fluids is the best thing you can do!


Call To Complete

Need Help?
Call Our CareTeam


Our CareTeam Member will guide you to complete your order