Gliogen 20 Capsule contains Temozolomide 20 mg, an oral alkylating agent primarily used in the treatment of certain types of brain tumors, including glioblastoma multiforme and anaplastic astrocytoma. Temozolomide is a prodrug that undergoes spontaneous conversion to its active metabolite, MTIC (monomethyl triazeno imidazole carboxamide), which exerts cytotoxic effects by methylating DNA at the O6 and N7 positions of guanine residues. This methylation leads to DNA strand breaks and apoptosis in rapidly dividing tumor cells. Gliogen 20 Capsule is indicated as a first-line treatment in combination with radiotherapy or as maintenance therapy following initial treatment. It is also used in recurrent cases where surgical options are limited. The medication is administered orally, allowing for convenient outpatient management. Common adverse effects include myelosuppression, nausea, vomiting, fatigue, and headache, necessitating regular monitoring of blood counts and liver function during therapy. Contraindications include hypersensitivity to Temozolomide or dacarbazine and severe bone marrow suppression. Caution is advised in patients with hepatic or renal impairment. Gliogen 20 Capsule should be prescribed and monitored by oncology specialists experienced in chemotherapy management to optimize therapeutic outcomes and minimize toxicity.