Product Intro:
Gliogrey is a sterile lyophilized powder for intravenous injection, available in 20 mg and 250 mg vials. It is primarily used in neuro-oncology protocols, either alone or in combination with radiotherapy, as a first-line or adjuvant chemotherapy in malignant brain tumors.
Uses (Indications):
Temozolomide is specifically designed for the treatment of aggressive brain tumors:
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Glioblastoma Multiforme (GBM) – newly diagnosed, in combination with radiotherapy and as maintenance monotherapy
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Anaplastic Astrocytoma – recurrent or progressive cases after standard therapy failure
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Malignant Gliomas – including mixed oligoastrocytomas
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Metastatic Brain Lesions – in some off-label or investigational settings
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Melanoma (off-label) – when metastasized to the brain or CNS
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Other CNS tumors (investigational) – such as medulloblastoma, oligodendroglioma
Storage Instructions:
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Store the vials at 20°C to 25°C (room temperature)
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Protect from light, moisture, and heat
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After reconstitution, use immediately or within 1 hour if stored at 2–8°C
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Do not freeze
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Store in a secure cytotoxic drug cabinet with proper labeling and PPE protocols
How It Works (Mechanism of Action):
Temozolomide is a DNA-alkylating agent. Once administered, it undergoes spontaneous conversion to MTIC (monomethyl triazeno imidazole carboxamide), its active metabolite.
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MTIC alkylates/methylates DNA at the O6 and N7 positions of guanine, leading to DNA strand breaks
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This causes mismatch repair, triggering apoptosis (programmed cell death) in rapidly dividing tumor cells
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It crosses the blood-brain barrier effectively, making it ideal for CNS malignancies
Side Effects:
Common Side Effects:
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Nausea and vomiting
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Fatigue and drowsiness
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Constipation or diarrhea
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Loss of appetite
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Headache
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Alopecia (hair loss)
Serious Side Effects:
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Severe myelosuppression – especially neutropenia and thrombocytopenia
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Pneumocystis jirovecii pneumonia (PJP) – especially in patients on long courses or with steroids
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Hepatotoxicity – elevated liver enzymes or liver failure
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Seizures or worsening neurological status
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Hypersensitivity reactions – including rash, swelling, or anaphylaxis
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Secondary malignancies – such as myelodysplastic syndrome or leukemia (rare, long-term)
Dosage (Typical Recommended Dose):
Newly Diagnosed Glioblastoma Multiforme:
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Concurrent with radiotherapy: 75 mg/m² daily for 42 days with radiotherapy
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Maintenance phase: 150–200 mg/m² once daily for 5 days every 28 days (starting 4 weeks post-radiation)
Recurrent Anaplastic Astrocytoma:
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150 mg/m² once daily for 5 consecutive days every 28-day cycle
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Dose may be escalated to 200 mg/m² if well tolerated
Note: Dose adjustments are based on hematologic recovery and liver function.
Method of Administration:
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Reconstitute the powder using sterile water for injection under aseptic conditions
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Administer via intravenous infusion over 90 minutes
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Do not administer as a bolus or push
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Requires special handling precautions due to cytotoxicity
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Can also be used in oral form; IV use is reserved for patients unable to take oral medication
Precautions:
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Monitor CBC, renal, and liver function before each cycle
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Prophylactic antibiotics (e.g., trimethoprim-sulfamethoxazole) may be required to prevent PJP
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Avoid use in pregnancy (Category D) – may cause fetal harm
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Use contraception during and for at least 6 months (females) and 3 months (males) after treatment
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Avoid use with immunosuppressive agents unless essential
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Monitor for signs of neurotoxicity or cognitive decline
Drug Interactions:
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Corticosteroids (e.g., dexamethasone): May increase risk of infection or immunosuppression
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Antiepileptics (e.g., phenytoin, valproate): May alter seizure threshold or drug levels
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Myelosuppressive agents: Additive risk of bone marrow toxicity
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Live vaccines: Contraindicated during and after treatment due to immunosuppression
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Hepatotoxic drugs: Increase risk of liver enzyme elevations
Allergies (Warnings for Allergic Reactions):
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Avoid use in patients with known hypersensitivity to temozolomide or dacarbazine (DTIC)
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Monitor for signs of angioedema, rash, urticaria, or anaphylaxis
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In case of severe reaction, discontinue immediately and initiate emergency treatment
Overdose Information:
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Symptoms include severe myelosuppression, mucositis, seizures, and risk of infection
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There is no specific antidote for temozolomide overdose
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Management is supportive, including transfusions, antibiotics, hydration, and close monitoring
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Hospitalization may be required for aggressive supportive care
Missed Dose Instructions:
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If a dose is missed, consult the oncology team immediately
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Do not double up or take extra doses without physician approval
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Dosing schedules are strictly managed under medical supervision during chemotherapy cycles
Additional Notes:
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Temozolomide is teratogenic and mutagenic – handle with PPE and dispose safely
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Regular MRI and imaging may be required to assess tumor response
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Patients may need psychological and nutritional support due to the neuro-oncologic burden
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Avoid alcohol and tobacco during treatment due to interaction and toxicity risks
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Adherence to infection control measures is essential due to bone marrow suppression
