Generic Name: thioguanine (thye-oh-GWA-neen)
Medically reviewed by Drugs.com. Last updated on July 14, 2020.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antineoplastic Agent
Pharmacologic Class: Antimetabolite
Uses for thioguanine
Thioguanine is used to treat acute non-lymphocytic leukemia. It belongs to the group of medicines known as antimetabolites. Thioguanine interferes with the growth of cancer cells, which are eventually destroyed.
Thioguanine is available only with your doctor's prescription.
Before using thioguanine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For thioguanine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to thioguanine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of thioguanine in children. However, children are especially sensitive to the effects of thioguanine and may increase the risk of liver toxicity, which may require caution in patients receiving thioguanine.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of thioguanine in the elderly. However, elderly patients are more likely to have serious unwanted effects (eg, liver toxicity), which may require caution in patients receiving thioguanine.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking thioguanine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using thioguanine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of thioguanine. Make sure you tell your doctor if you have any other medical problems, especially:
- Infection—May decrease your body's ability to fight an infection.
- Liver disease—Effects may be increased because of slower removal of the medicine from the body.
- Thiopurine methyltransferase deficiency (genetic deficiency)—Use with caution. May make you more sensitive to the side effects of thioguanine.
Proper use of thioguanine
Medicines used to treat cancer are very strong and can have many side effects. Before using thioguanine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
Take thioguanine only as directed by your doctor. Do not take more or less of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
Thioguanine is sometimes given together with certain other medicines. Make sure that you take each one at the right time and do not mix them. Ask your health care professional to help you plan a way to take your medicine at the right times.
Limit the amount of alcohol you drink during treatment with thioguanine.
The dose of thioguanine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of thioguanine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For acute non-lymphocytic leukemia:
- Adults—Dose is based on body weight and must be determined by your doctor. At first, 2 milligrams per kilogram (mg/kg) of body weight per day for up to 4 weeks. Your doctor may adjust your dose as needed and tolerated.
- Children—Dose is based on body weight and must be determined by your doctor. At first, 2 milligrams per kilogram (mg/kg) of body weight per day for up to 4 weeks. Your doctor may adjust your dose as needed and tolerated.
- For acute non-lymphocytic leukemia:
Thioguanine needs to be given on a fixed schedule. If you miss a dose, call your doctor, home health caregiver, or treatment clinic for instructions.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using thioguanine
It is very important that your doctor check your or your child's progress at regular visits to make sure that thioguanine is working properly and to check for unwanted effects.
Do not use thioguanine if thioguanine or mercaptopurine (Purinethol®) has not been effective in treating your condition in the past.
Using thioguanine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant during treatment with thioguanine. If you think you have become pregnant while using thioguanine, tell your doctor right away.
Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.
Thioguanine can lower the number of white blood cells in your blood temporarily, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:
- If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
- Check with your doctor immediately if you notice any unusual bleeding or bruising, black, tarry stools, blood in urine or stools, or pinpoint red spots on your skin.
- Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
- Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
- Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
- Avoid contact sports or other situations where bruising or injury could occur.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Thioguanine side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Black, tarry stools
- blood in the urine or stools
- joint pain, stiffness, or swelling
- lower back, side, or stomach pain
- painful or difficult urination
- pinpoint red spots on the skin
- swelling of the feet or lower legs
- unusual bleeding or bruising
Incidence not known
- Bloody, black, or tarry stools
- decrease in the amount of urine
- noisy, rattling breathing
- right upper abdominal pain and fullness
- severe stomach pain, cramping, or burning
- stomach bloating
- swelling of the fingers or hands
- trouble breathing
- troubled breathing at rest
- vomiting of material that looks like coffee grounds, severe and continuing
- weight gain
- yellow eyes or skin
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Blurred vision
- cloudy urine
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
- dry mouth
- general feeling of discomfort or illness
- increased sweating
- unusual tiredness or weakness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Loss of appetite
- swelling or inflammation of the mouth
- weight loss
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about thioguanine
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Compare Alternatives
- En Español
- Drug class: antimetabolites
- Other brands
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.