Antineoplastic Agents

Cell Cycle Non-Specific:

Work in all phases, considered more toxic than cycle specific agents

Alkylating agents

Antitumor Antibodies

Hormones & Hormone Antagonists
This classification has 6 different groups w/ several drugs within each group.

Action:  Attack DNA
Commonly prescribed agents:
Nitrogen Mustards:

  • cylosphosphamide (Cytoxan)
  • Nitrosureas
  • Carmustine (BCNU)

Misc. Agents:

  • cisplatin (Platinol)

Adverse Effects:

  • Myelosuppression
  • Nausea & Vomiting
    • R/T to stimulation of chemoreceptor trigger zone
    • Very common S/E of chemo drugs – especially w/ the alkylating agents.
    • Pts premedicated for N/V
    • Notorious for delayed N/V
 Have anti-infective and cytotoxic properties.

Commonly prescribed agents:

  • doxorubicin (Adriamycin)
  • daunorubicin (Daunomycin)
  • bleomycin (Blexoxane)
  • dactinomycin (Actinomycin)

Adverse Effects:

  • Myelosuppression
  • GI disturbances: N/V
  • Cardiotoxicity – CHF
  • Pulmonary toxicity
  • pulmonary infiltrates, pulmonary edema
 Natural chemicals secreted by endocrine glands that affect cell growth. No cytotoxic activity
Action: block cell metabolism
Because these drugs target specific receptor sites, they are the least toxic of all cancer drugs. Adverse reactions vary.

Target tumor cells must have hormone receptor sites

  • Categories:
    • Androgens
    • Estrogens
    • Progestins
    • Corticosteroids
    • Gonadotropin-releasing hormones
    • And analog and antihormonal agents
  • Indications
    • Breast & prostate cancer
    • Palliation

Common Types:

  • Androgens – palliative therapy for women w/ metastatic breast cancer.
  • Antiandrogens – treatment of metastatic prostate cancer.
  • Estrogens – prostate cancer and advanced breast cancer in postmenopausal women. Can offer palliation and induce tumor regression.
  • Antiestrogens – such as tamoxifen (Nolvadex). Used to treat advanced breast cancer in pre- and postmenopausal women. The target cells must possess estrogen receptor sites.
  • Progestins – such as medroxyprogesterone acetate (Depo-Provera) and megestrol (Megace) treatment of advanced endometrial cancer.


Cell Cycle Specific Drugs

Antimetabolites

Plant Alkaloids
Antimetabolites interfere w/ DNA and RNA synthesis by substituting or mimicking natural metabolites, causing the wrong information to be given to the cell. The tumor cells then reproduce cells that fail to function.

Structural analogs for natural metabolites necessary for cell function.

Three types:

  1. Folic acid antagonists: methotrexate (Folex)

*Leucovorin Rescue- antidote for folic acid antagonists

  1. Purine antagonists: mercaptopurine (6MP)
  1. Pyramidine antagonists: fluorouracil (5 FU)

Common Adverse Effects:

      • Myelosuppression
      • GI disturbances – N/V/D
      • Hepatotoxicity
      • Hyperuricemia

*Leucovorin is a reduced form of folic acid, which is readily converted to other reduced folic acid derivatives (e.g., tetrahydrofolate).

Because it does not require reduction by dihydrofolate reductase as does folic acid, leucovorin is not affected by blockage of this enzyme by folic acid antagonists (dihydrofolate reductase inhibitors). This allows purine and thymidine synthesis, and thus DNA, RNA and protein synthesis, to occur. Leucovorin may limit methotrexate action on normal cells by competing with methotrexate for the same transport processes into the cell. Leucovorin rescues bone marrow and gastrointestinal cells from methotrexate but has no apparent effect on pre-existing methotrexate nephrotoxicity.

 Also called mitotic inhibitors
Common agents:

  • Vinca alkaloids
    • Vinblastine sulfate (Velban)
    • Vincristin sulfate (Oncovin)
  • Taxoids
  • Topoisomerase inhibitors

Vincristing: Derived from the periwinkle plant

Act in M, G2, & S phase; crystallize microtubular spindle proteins during cell cycle

Route: Mostly IV

Common Adverse Effects:

  • Myelosuppression
  • Neurotoxicity:
    • peripheral neuropathy – sensory and motor nerve injury.
    • Injury to the ANS results in constipation and urinary hesitancy.
    • Does not enter the brain, so injury to the brain is minimal.
  • Vesicant:  powerful irritant, if enters SQ tissue can cause severe tissue sloughing at site.  If infiltration occurs?

Mmyelosuppression is considered to be far less a problem w/ this vinca alkaloids.Because of this, often selected as a second drug when possible for combination therapy.