Antineoplastic

Antineoplastic agents, also known as anticancer or chemotherapeutic agents, are substances that inhibit the growth and spread of neoplastic cells. These agents are primarily used in the treatment of cancer, aiming to destroy malignant cells while sparing normal, healthy cells as much as possible.

Classification

Antineoplastic agents can be classified into several categories based on their mechanism of action:

• Alkylating agents: These compounds work by adding an alkyl group to the DNA of cancer cells, which interferes with their replication. Examples include cyclophosphamide and chlorambucil.
• Antimetabolites: These agents mimic the building blocks of DNA or RNA, thereby inhibiting cell division. Common antimetabolites include methotrexate and 5-fluorouracil.
• Natural products: This category includes a variety of plant-derived compounds such as vincristine and paclitaxel.
• Topoisomerase inhibitors: These drugs interfere with the action of topoisomerase enzymes, which are essential for DNA replication. Examples include doxorubicin and etoposide.
• Antitumor antibiotics: These are not the same as antibiotics used to treat infections. They work by binding to DNA and preventing RNA synthesis. Examples include bleomycin and mitomycin.
• Hormonal agents: These drugs are used to treat cancers that are sensitive to hormones, such as breast cancer and prostate cancer. Examples include tamoxifen and flutamide.
• Targeted therapy: These agents specifically target cancer cells with minimal effects on normal cells. Examples include imatinib and trastuzumab.

Mechanism of Action

Antineoplastic agents work through various mechanisms to inhibit the growth of cancer cells:

• **DNA Damage**: Many antineoplastic agents cause direct damage to the DNA of cancer cells, leading to cell death.
• **Inhibition of Cell Division**: Some agents interfere with the cell cycle, preventing cancer cells from dividing and proliferating.
• **Induction of Apoptosis**: Certain drugs trigger programmed cell death (apoptosis) in cancer cells.
• **Inhibition of Angiogenesis**: Some agents prevent the formation of new blood vessels (angiogenesis) that tumors need to grow.

Side Effects

The use of antineoplastic agents is often associated with a range of side effects due to their impact on rapidly dividing cells, both cancerous and normal. Common side effects include:

• Nausea and vomiting
• Hair loss
• Myelosuppression (decreased production of blood cells)
• Fatigue
• Mucositis (inflammation of the mucous membranes)

Administration

Antineoplastic agents can be administered in various ways, including:

• **Oral**: Taken by mouth in the form of pills or liquids.
• **Intravenous (IV)**: Delivered directly into the bloodstream through a vein.
• **Intramuscular (IM)**: Injected into a muscle.
• **Topical**: Applied directly to the skin.

History

The development of antineoplastic agents began in the early 20th century with the discovery of mustard gas derivatives. Over the decades, significant advancements have been made, leading to the development of more effective and targeted therapies.

Future Directions

Research in the field of antineoplastic agents is ongoing, with a focus on developing more targeted therapies that minimize side effects and improve patient outcomes. Immunotherapy and personalized medicine are promising areas of research.

See Also

• Chemotherapy
• Radiation therapy
• Oncology
• Cancer research
• Immunotherapy