THIOGUANINE
Background and Date of Approval
Thioguanine contains the active ingredient thioguanine. It is indicated for the treatment of blood cancers, specifically acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL). Acute myelogenous leukemia is a rapidly progressing disorder characterised by increased production of white blood cells in the bone marrow, which can result in infections and bleeding. Acute lymphoblastic leukemia (ALL) is characterised by the accumulation of immature white blood cells due to abnormal white blood cell production in the bone marrow. This condition is more prevalent in children aged below 5 years. Thioguanine received initial approval from the US FDA in 1966 for the treatment of acute myeloid leukaemia.
Uses
Thioguanine uses in the treatment of acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML).
How is it administered?
Thioguanine is usually taken orally in the form of tablets. The tablets should be swallowed whole with water or another liquid, and should not be crushed, chewed, or broken. It is generally recommended to take it on an empty stomach, either one hour before or two hours after meals, to help maximize its absorption and effectiveness. Do not take a double dose to make up for a missed one.
Side Effects
Thioguanine can cause a range of side effects, both mild and serious. Common side effects may include nausea, vomiting, diarrhea, loss of appetite, and changes in taste. It may also cause bone marrow suppression, which can lead to anemia, neutropenia, and thrombocytopenia. Serious side effects may include liver toxicity, pulmonary toxicity, pancreatitis, and hypersensitivity reactions. It can also increase the risk of developing infections and may increase the risk of developing certain types of cancers.
Warnings
Thioguanine can cause bone marrow suppression, which can lead to decreased blood cell counts. This can increase the risk of infections, bleeding, and anemia. It may increase the risk of developing certain types of cancer, including lymphoma and leukemia. The risk is highest in people who receive high doses of thioguanine or who take it for prolonged periods of time. This medicine can cause a condition called hyperuricemia, which is an excess of uric acid in the blood. This can lead to gout or kidney stones. Also, this medication can cause skin reactions, including rash, itching, and photosensitivity. In rare cases, it can cause vision changes or other eye problems, including cataracts or optic neuritis. Sometimes this medication shows neurological side effects, including confusion, memory problems, and seizures.
Precautions
Your healthcare provider will monitor your blood cell counts and uric acid level regularly during treatment with thioguanine. If you experience vision changes or other eye symptoms, neurological symptoms, and skin reactions seek medical attention immediately.
Word of Advice
Discuss any concerns regarding thioguanine with your healthcare provider. Patients with a history of allergy to thioguanine or any of its components should avoid this medication. Pregnancy and breastfeeding are contraindications to thioguanine use. Women of reproductive potential should use contraception during treatment and for several weeks after completion. Avoid grapefruit consumption during treatment. Minimise risk of falls and sharp cuts, as thioguanine increases bleeding tendency and infection risk. Follow dosing instructions and precautions as directed by your doctor. Report any side effects or adverse reactions to your healthcare provider. Do not stop or alter your medication regimen without consulting your healthcare provider.
References
Aspen Pharma Trading Limited, Electronic Medicines Compendium (EMC), [Revised on Sep 2017] [Accessed on 27th April 2023], https://www.medicines.org.uk/emc/files/pil.4654.pdf H.G. Watson, J.I.O. Craig, L.M. Manson, Blood disease, Davidsonâs Principles and Practice of Medicine, 22nd Edition, 2014, 989-1056. Edward Chu, Cancer Chemotherapy, Langeâs Basic and Clinical Pharmacology, 14th Edition, 2018, 948-976 Apsen Global Inc, U.S Drud and Food Safety Administration (FDA), [Revised on May, 2018], [Accessed on 27th April 2023] https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/012429s028lbl.pdf
Frequently Asked Questions
Can I take thioguanine if I have tuberculosis?
The use of thioguanine may not be recommended if you have tuberculosis (TB). It can suppress the immune system, which can increase the risk of developing infections such as TB or reactivating latent TB infections. If you have active TB or a history of TB, it is important to discuss this with your healthcare provider before starting treatment with this medication.
Can I take this medicine if I have kidney stones?
The use of thioguanine may not be recommended if you have a history of kidney stones or impaired kidney function. It can increase the levels of uric acid in the body, which can contribute to the formation of kidney stones. In addition, this medication is eliminated from the body primarily through the kidneys, so impaired kidney function can affect the clearance of the drug from the body, leading to a higher risk of side effects.
How thioguanine will affect my heart?
Thioguanine can affect the function of the heart and blood vessels, leading to conditions such as hypertension (high blood pressure) and cardiomyopathy (disease of the heart muscle). The risk of these side effects may be increased if you have a history of heart disease or if you take other medications that can affect the heart.
Can thioguanine cause hair loss?
Hair loss is not a common side effect of thioguanine, but it may occur in some people. If you experience hair loss while taking it, discuss it with your healthcare provider.
Does thioguanine affect fertility?
Thioguanine may affect fertility in men and women, but the extent of the effect is not well-established. If you are concerned about fertility, discuss your options with your healthcare provider.
Can thioguanine be used during radiation therapy?
Thioguanine may interact with radiation therapy and may not be safe for use during treatment. If you are undergoing radiation therapy or planning to, discuss your options with your healthcare provider.