Thioguanine

Generic name: thioguanine
Brand name: Tabloid
Dosage form: oral tablet (40 mg)
Drug class: Antimetabolites

Medically reviewed by A Ras MD.

What is thioguanine?

Thioguanine is a prescription medicine that is used to treat a type of leukemia.

Description

TABLOID brand Thioguanine was synthesized and developed by Hitchings, Elion, and associates at the Wellcome Research Laboratories. It is one of a large series of purine analogues which interfere with nucleic acid biosynthesis, and has been found active against selected human neoplastic diseases.

Thioguanine, known chemically as 2-amino-1,7-dihydro-6H-purine-6-thione, is an analogue of the nucleic acid constituent guanine, and is closely related structurally and functionally to PURINETHOL® (mercaptopurine). Its structural formula is:

TABLOID brand Thioguanine is available in tablets for oral administration. Each scored tablet contains 40 mg thioguanine and the inactive ingredients acacia, lactose monohydrate, magnesium stearate, potato starch, and stearic acid.

Before taking thioguanine, tell your doctor:

If you are allergic to thioguanine; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
If you are breast-feeding or plan to breast-feed.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take thioguanine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take thioguanine?

Tell all of your health care providers that you take thioguanine. This includes your doctors, nurses, pharmacists, and dentists.
You may have more chance of getting an infection. Wash hands often. Stay away from people with infections, colds, or flu.
You may bleed more easily. Be careful and avoid injury. Use a soft toothbrush and an electric razor.
Very bad and sometimes life-threatening blood and bone marrow problems like anemia, low platelet counts, or low white blood cell counts have happened with thioguanine. Change in dose or even stopping the drug may be needed if any of these side effects happen. Talk with the doctor.
If you have upset stomach, throwing up, diarrhea, or are not hungry, talk with your doctor. There may be ways to lower these side effects.
This medicine may add to the chance of getting some types of cancer. Talk with the doctor.
Have blood work checked as you have been told by the doctor. Talk with the doctor.
Watch for gout attacks.
You may get sunburned more easily. Avoid sun, sunlamps, and tanning beds. Use sunscreen and wear clothing and eyewear that protects you from the sun.
If you have thiopurine S-methyltransferase (TPMT) or nucleotide diphosphatase (NUDT15) deficiency, talk with your doctor.
Talk with your doctor before getting any vaccines. Use of some vaccines with thioguanine may either raise the chance of an infection or make the vaccine not work as well.
This medicine may cause harm to the unborn baby if you take it while you are pregnant.
Use birth control that you can trust to prevent pregnancy while taking thioguanine.
If you are pregnant or you get pregnant while taking thioguanine, call your doctor right away.

How is thioguanine best taken?

Use thioguanine as ordered by your doctor. Read all information given to you. Follow all instructions closely.

Do not take thioguanine for longer than you were told by your doctor.
You will need to take special care when handling thioguanine. Check with the doctor or pharmacist to see how to handle thioguanine.
Drink lots of noncaffeine liquids unless told to drink less liquid by your doctor.

What do I do if I miss a dose?

Take a missed dose as soon as you think about it.
If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
Do not take 2 doses at the same time or extra doses.

What are the side effects of thioguanine that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Signs of infection like fever, chills, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or wound that will not heal.
Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
Signs of bleeding like throwing up or coughing up blood; vomit that looks like coffee grounds; blood in the urine; black, red, or tarry stools; bleeding from the gums; abnormal vaginal bleeding; bruises without a cause or that get bigger; or bleeding you cannot stop.
Feeling very tired or weak.
Swelling of belly.
A big weight gain.
Patients with cancer who take thioguanine may be at a greater risk of getting a severe health problem called tumor lysis syndrome (TLS).This may lead to death. Call your doctor right away if you have a fast or abnormal heartbeat; any passing out; trouble passing urine; muscle weakness or cramps; upset stomach, throwing up, diarrhea, or not able to eat; or feel sluggish.

What are some other side effects of thioguanine?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

Upset stomach or throwing up.
Not hungry.
Mouth irritation or mouth sores.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out thioguanine?

Store at room temperature.
Store in a dry place. Do not store in a bathroom.
Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.