Drug Groups

approved; investigational

Description

Temozolomide (Temodar and Temodal) is an oral alkylating agent used for the treatment of refractory anaplastic astrocytoma -- a type of cancerous brain tumor. Temozolomide is not active until it is converted at physiologic pH to the active form, 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide (MTIC).

Indication

For the treatment of adult patients diagnosed with anaplastic astrocytoma whose disease has progressed after therapy with nitrosourea and procarbazine, as well as concomitantly with radiation therapy for treatment of newly diagnosed glioblastoma multiforme. Also used as maintenance therapy for glioblastoma multiforme.

Pharmacology

Temozolomide is an imidazotetrazine deritave and an antineoplastic agent. It is a prodrug that has little to no pharmacological activity until it is hydrolyzed in vivo to 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide (MTIC). After administration, temozolomide undergoes rapid, nonenzymatic hydrolysis at physiological pH to MTIC, which is the active form of the drug. MTIC is generated through the effect of water at the highly electropositive C4 position of temozolomide, causing the ring of temozolomide to open, release carbon dioxide, and generate MTIC.

Affected Organisms

Absorption

Rapid and complete absorption in the gastrointestinal tract

Half Life

Approximately 1.8 hours.

Protein Binding

15%

Elimination

About 38% of the administered temozolomide total radioactive dose is recovered over 7 days: 37.7% in urine and 0.8% in feces.

Distribution

* 0.4 L/kg

Clearance

* 5.5 L/hr/m2

References

External Links