How it is administered

Tioguanine is administered orally in the form of tablets. Each tablet typically contains 40 mg of tioguanine. The total daily dose may be given at one time, and dosing is based on body weight (mg/kg/day).

How it works

Tioguanine is a purine analogue, which means it mimics the structure of natural purines found in DNA and RNA. Once inside the body, tioguanine is converted into active metabolites that interfere with the synthesis and function of nucleic acids. This interference disrupts the growth and division of rapidly dividing cells, such as cancer cells.

Specifically, tioguanine is incorporated into the DNA and RNA of bone marrow cells, replacing the normal base guanine. This leads to faulty genetic material and blocks the production of new purine nucleotides, which are essential for cell growth. The result is a sequential blockade of the synthesis and utilization of purine nucleotides, ultimately causing cell death, especially in rapidly dividing cancer cells. The drug's effects are long-lasting due to its active metabolites remaining in cells even after the parent drug has left the bloodstream.

Who Should take it

Tioguanine is indicated for the remission induction and consolidation treatment of acute nonlymphocytic leukemias. It is usually used as part of a combination chemotherapy regimen rather than as a single agent, as combination therapy has been shown to produce more frequent and longer-lasting remissions.

While tioguanine is not specifically indicated for lymphoblastic lymphoma, it may be used in certain blood cancers as part of a multi-drug protocol. The decision to use tioguanine should be made by a physician experienced in cancer chemotherapy and familiar with the specific disease being treated.

Who should not take it

Tioguanine should not be used in patients whose disease has previously shown resistance to this drug. There is usually complete cross-resistance between tioguanine and mercaptopurine, so if one is ineffective, the other is unlikely to work.

Patients with inherited deficiencies of the enzyme thiopurine methyltransferase (TPMT) or NUDT15 may be at higher risk for severe bone marrow suppression and may require significant dose reductions. Tioguanine is also not recommended for maintenance therapy or long-term continuous use due to a high risk of liver toxicity. It should not be used in pregnant women unless absolutely necessary, as it may cause harm to the fetus.

Commonly used with

Tioguanine is commonly used in combination with other chemotherapy agents such as cytarabine, cyclophosphamide, prednisone, and vincristine. These combinations are designed to increase the effectiveness of treatment by attacking cancer cells in different ways.

It may also be used alongside supportive medications like allopurinol to manage side effects such as hyperuricemia.

Commonly tested with

Tioguanine is often tested in combination with other chemotherapeutic agents, particularly cytarabine and cyclophosphamide, as part of multi-drug regimens for the treatment of acute leukemias. These combinations are used in clinical trials and standard treatment protocols to assess their efficacy and safety in inducing and maintaining remission.