Pediatric Astrocytoma Medication

Updated: Aug 18, 2017
  • Author: Lauren R Weintraub, MD; Chief Editor: Max J Coppes, MD, PhD, MBA  more...
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Medication

Antineoplastic agents

Class Summary

These agents disrupt DNA replication, which inhibits tumor growth and promotes tumor cell death. Cancer chemotherapy is based on an understanding of tumor cell growth and how drugs affect this growth. After cells divide, they enter a period of growth (phase G1), followed by DNA synthesis (phase S). The next phase is a premitotic phase (G2), then finally a mitotic cell division (phase M).

The cell division rate varies for different tumors. Most common cancers increase very slowly in size compared to normal tissues, and the rate may decrease further in large tumors. This difference allows normal cells to recover from chemotherapy more quickly than malignant ones and is the rationale behind current cyclic dosage schedules.

Antineoplastic agents interfere with cell reproduction. Some agents are cell cycle specific, while others (eg, alkylating agents, anthracyclines, cisplatin) are not phase-specific. Cellular apoptosis (ie, programmed cell death) is also a potential mechanism of many antineoplastic agents.

Temozolomide (Temodar)

Prodrug that is hydrolyzed to MTIC at physiologic pH. Exerts its effect by site-specific DNA cross-linking resulting from the methylation guanine at the O6 and N7 positions. Bioavailability is 100%; approximately 35% crosses the blood-brain barrier.

Carboplatin (Paraplatin)

Analog of cisplatin. This is a heavy metal coordination complex that exerts its cytotoxic effect by platination of DNA, a mechanism analogous to alkylation, leading to interstrand and intrastrand DNA crosslinks and inhibition of DNA replication.

Vincristine (Oncovin)

Plant-derived vinca alkaloid. Acts as a mitotic inhibitor by binding tubulin.

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Monoclonal antibody

Bevacizumab

Recombinant humanized monoclonal antibody to VEGF; blocks the angiogenic molecule VEGF thereby inhibiting tumor angiogenesis, starving tumor of blood and nutrients.

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