When This Medicine Should Not Be Used:
You should not use this medicine if thioguanine or mercaptopurine (Purinethol®) have not been effective in treating your condition in the past.

How to Use This Medicine:
Tablet

• Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
• Your doctor will tell you how much medicine to use. Do not use more than directed.
• Drink at least 6 to 8 large glasses of liquid every day while you are using this medicine.
• If you vomit right after you take this medicine, call your doctor.

Drugs and Foods to Avoid:
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Make sure your doctor knows if you are also using mesalamine (Asacol®, Pentasa®), olsalazine (Dipentum®) or sulfasalazine (Azulfidine®).
• Do not drink alcohol while you are using this medicine.
• You should not use aspirin or any product that has aspirin in it (such as some cold medicines) unless you have talked to your doctor.
• This medicine may interfere with vaccines. Ask your doctor before you get a flu shot or any other vaccines.

Warnings While Using This Medicine:

• It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant.
• Tell your doctor if you have gout, liver disease, or a history of kidney stones.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• This medicine may make you bleed, bruise, or get infections more easily. Take precautions to prevent illness and injury. Wash your hands often.
• This medicine may make your mouth sore and irritated. Use a soft-bristle toothbrush or mouth swab to brush your teeth.

Possible Side Effects While Using This Medicine:
Call your doctor right away if you notice any of these side effects:

• Bloody or black, tarry stools.
• Dark-colored urine or pale stools.
• Fever, chills, cough, sore throat, and body aches.
• Lightheadedness or fainting.
• Nausea, vomiting, loss of appetite, pain in your upper stomach.
• Pale skin, weakness.
• Severe mouth sores that keep you from drinking liquids.
• Stomach pain, especially on the right side of your stomach.
• Unusual bruising or bleeding.
• Yellowing of your skin or the whites of your eyes.

If you notice these less serious side effects, talk with your doctor:

• Mild diarrhea.

If you notice other side effects that you think are caused by this medicine, tell your doctor.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088