Mercaptopurine (By Mouth)

Mercaptopurine (mer-kap-toe-PYOOR-een)

Treats leukemia.

Brand Name(s):

Purinethol
There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you had an allergic reaction to mercaptopurine or thioguanine, or if you have ever been treated with mercaptopurine or thioguanine (Tabloid®) and the medicines did not work. You should not use mercaptopurine if you are pregnant.

How to Use This Medicine:

Tablet

• Your doctor will tell you how much of this medicine to take and how often. Do not take more medicine or take it more often than your doctor tells you to.
• Drink extra fluids so you will pass more urine while you are using this medicine. This will keep your kidneys working well and help prevent kidney problems.

If a dose is missed:

• If you miss a dose or forget to take your medicine, take it as soon as you can. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose.
• Do not use extra medicine to make up for a missed dose.

How to Store and Dispose of This Medicine:

• Store the medicine at room temperature, away from heat, moisture, and direct light.
• Keep all medicine away from children and never share your medicine with anyone.

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 a blood thinner (Coumadin®), allopurinol (Zyloprim®), cotrimoxazole (Bactrim®), olsalazine (Dipentum®), mesalamine (Asacol®), or sulfasalazine (Azulfidine®).
• Talk to your doctor before getting flu shots or other vaccines while you are receiving mercaptopurine. Vaccines may not work as well while you are using this medicine.

Warnings While Using This Medicine:

• Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.
• Make sure your doctor knows if you are breastfeeding, or if you have liver disease, kidney disease, gout, or inflammatory bowel disease.
• Your doctor will need to check your blood or urine at regular visits while you are using this medicine. Be sure to keep all appointments.
• This medicine lowers the number of some types of blood cells in your body. Because of this, you may bleed or get infections more easily. To help with these problems, avoid being near people who are sick or have infections. Wash your hands often. Stay away from rough sports or other situations where you could be bruised, cut, or injured. Brush and floss your teeth gently. Be careful when using sharp objects, including razors and fingernail clippers.

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
• Nausea, vomiting, diarrhea, loss of appetite, pain in the upper stomach
• Severe pain or swelling in your joints
• Unexplained fever, sore throat, chills
• Unusual bleeding, bruising, or weakness
• Yellow skin or eyes

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

• Darkening of skin color
• Mild diarrhea
• Mild skin rash

If you notice other side effects that you think are caused by this medicine, tell your doctor.