Thioguanine

• Thioguanine is a chemotherapy drug primarily used for acute myeloid leukemia (AML).
• It functions by disrupting DNA and RNA synthesis in rapidly dividing cancer cells.
• Dosage is highly individualized, based on patient factors and blood counts.
• Common side effects include nausea, vomiting, and bone marrow suppression.
• Regular monitoring by a healthcare professional is crucial during treatment.

What is Thioguanine and How It Works

Thioguanine, also known as 6-thioguanine (6-TG), is a purine analogue antimetabolite chemotherapy drug. It is primarily used in the treatment of certain types of leukemia, particularly acute myeloid leukemia (AML). As a cytotoxic agent, its main role is to inhibit the proliferation of rapidly growing cells, including cancer cells.

Thioguanine works by being incorporated into the DNA and RNA of cancer cells. Once inside the cell, thioguanine is converted into active metabolites that interfere with nucleic acid synthesis. This disruption prevents the cancer cells from properly replicating their genetic material and synthesizing proteins, which is essential for cell division and growth. Consequently, this leads to cell cycle arrest and programmed cell death (apoptosis) in the malignant cells, thereby slowing or stopping the progression of the cancer.

Uses and Dosage of Thioguanine

Thioguanine is primarily used for the treatment of acute myeloid leukemia (AML), often as part of combination chemotherapy regimens. It may also be used in other myeloproliferative disorders. The specific conditions for which it is prescribed are determined by a healthcare professional based on the patient’s diagnosis and overall treatment plan.

Thioguanine dosage information is highly individualized and depends on several factors, including the patient’s body surface area, kidney and liver function, bone marrow reserve, and the specific type of leukemia being treated. It is typically administered orally, but intravenous forms may also exist. Dosage adjustments are frequently made based on the patient’s response to treatment and the development of side effects, particularly bone marrow suppression. Close monitoring of blood counts is essential throughout the treatment period to ensure appropriate dosing and manage potential toxicities. Patients should never adjust their dose without consulting their prescribing physician.

Thioguanine Side Effects

Like all chemotherapy drugs, thioguanine can cause a range of side effects due to its impact on rapidly dividing healthy cells in addition to cancer cells. These can vary in severity and may include:

• Gastrointestinal issues: Nausea, vomiting, diarrhea, and loss of appetite are common.
• Bone marrow suppression: This is a significant concern and can lead to a decrease in white blood cells (increasing infection risk), red blood cells (anemia), and platelets (increased bleeding risk).
• Liver toxicity: Elevated liver enzymes and, in some cases, veno-occlusive disease of the liver, can occur. Regular liver function tests are crucial.
• Oral mucositis: Sores or inflammation in the mouth and throat.
• Skin reactions: Rash or itching.

Patients should report any new or worsening symptoms to their doctor immediately. Management of side effects often involves supportive care, such as anti-nausea medications, antibiotics for infections, and blood transfusions if needed. Long-term monitoring is also important, especially for potential liver complications.