Temozolomide in Brain Cancer

Temozolomide is an oral chemotherapy drug that has revolutionized the treatment of glioblastoma multiforme and refractory anaplastic astrocytoma, a type of brain cancer. In this blog, we’ll cover temozolomide’s mechanism of action, its use in treating brain cancer, potential side effects, and its impact on patients with malignant gliomas.

About Temozolomide

Temozolomide, an imidazotetrazine prodrug, exhibits stability under acidic pH conditions but spontaneously undergoes nonenzymatic hydrolysis in neutral or slightly basic environments. This characteristic enables its administration via both oral and intravenous routes. 

Upon initial hydrolysis, it releases a highly reactive methyl diazonium cation capable of methylating various adenosine and guanine residues, leading to DNA damage and eventual apoptosis. Temozolomide, when used adjunctively with radiotherapy followed by maintenance dosing, remains the standard treatment for both Glioblastoma and refractory anaplastic astrocytoma.

Mechanism of Action:

Temozolomide, an alkylating agent, disrupts cancer cell DNA, inducing cell death. Converted to its active form, MTIC, in the body, it binds to DNA, causing damage and targeting rapidly dividing cells, notably effective against malignant gliomas.

Role in the Treatment of Brain Cancer:

Temozolomide is approved for the treatment of adult patients with newly diagnosed glioblastoma multiforme (GBM) and for the treatment of adult patients with refractory anaplastic astrocytoma (AA) who have experienced disease progression on a drug regimen containing nitrosourea and procarbazine. 

It is administered orally, typically once daily, and has demonstrated impressive efficacy in clinical trials. Compared to standard treatments like nitrosoureas, temozolomide offers better overall response rates, progression-free survival, and tolerability profiles.

Dosing Of Temozolomide 

• For newly diagnosed GBM, the recommended treatment regimen involves administering a dose of 75 mg/m² for 42 days alongside focal radiotherapy, followed by a maintenance dose of 150 mg/m² once daily for Days 1-5 of a 28-day cycle of Temozolomide for a total of 6 cycles. 
• For refractory Anaplastic Astrocytoma, the initial dose is 150 mg/m² once daily for 5 consecutive days per 28-day treatment cycle. 
• It’s important to note that the recommended dose for Temozolomide administered intravenously over 90 minutes is the same as the oral capsule formulation, with established bioequivalence under this administration method.

Potential Side Effects of Temozolomide 

Blood cell problems:

• Decreased white blood cells (neutropenia): This increases your risk of infection.
• Decreased red blood cells (anemia): This can cause fatigue and shortness of breath.
• Decreased platelets (thrombocytopenia): This increases your risk of bleeding.

Other common side effects:

• Nausea and vomiting
• Constipation
• Fatigue
• Hair loss
• Loss of appetite
• Mouth sores
• Headache 
• Muscle cramps
• Skin rash.

Less common, but more serious, side effects include:

• Blood clots: This is a rare but serious side effect. Tell your doctor right away if you experience symptoms like pain, swelling, redness, or warmth in your legs or arms.
• Liver problems: Your doctor will monitor your liver function with blood tests during treatment.
• Pneumonia: People taking Temozolomide have an increased risk of pneumonia. Tell your doctor right away if you have symptoms like cough, fever, or shortness of breath.
• Second cancers: There is a small risk of developing other cancers later in life after taking Temozolomide.

Your doctor will closely monitor you for any adverse reactions and modify your treatment regimen accordingly. Don’t hesitate to communicate any concerns or discomfort you may encounter during treatment of Temozolomide. 

Conclusion:

Temozolomide is a significant advancement in treating malignant gliomas, offering targeted action, high efficacy, and manageable side effects. It’s a valuable option for brain cancer patients and is expected to remain pivotal in enhancing outcomes for those with this condition as research progresses. To check availability of generic brand of Temozolomide in India, interested individuals can contact the Patient Support Team at (+91) 9315705373 or via email at help@sansfro.com.