Chapter 21: Antineoplastic Drugs Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. Chapter 21 Outline Antineoplastic Drugs Use of antineoplastic agents Mechanisms of action Classification Adverse drug effects Combinations Dental implications Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 2 Antineoplastic Drugs Designed to treat malignancies Haveles (p. 269) May also be used for the treatment of diseases with an inflammatory component The dental health care worker should be aware of the timing of treatments and the effect on bone marrow Side effects include oral manifestations cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 3 Antineoplastic Drugs Mechanisms involved in the etiology of cancer include genetics, viruses, deleted or damaged tumor suppressor genes, specific oncogenes, and changes in both ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 4 Use of Antineoplastic Agents Haveles (pp. 269-270) (Box 21-1) Antineoplastic agents are used clinically to interfere with neoplastic cells Suppress growth and attempt to destroy and prevent the spread of malignant cells May be used alone or in combination or with radiation or surgery Current philosophy involves treating the initial stages of the disease very aggressively Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 5 Mechanisms of Action Haveles (pp. 270-271) (Fig. 21-1) Efficacy is based primarily on their ability to interfere with the metabolism or the reproductive cycle of tumor cells Four stages in the cycle G1: the postmitotic or pre-DNA synthesis phase S: period of DNA synthesis G2: premitotic or post-DNA synthesis phase M: period of mitosis cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 6 Mechanisms of Action Most antineoplastic agents are labeled as Cell-cycle specific: effective only at certain phases of cell growth Cell-cycle nonspecific: effective at all stages of the cycle Resistance is either De novo: the neoplasm was always resistant Acquired resistance: resistance through natural selection of mutations Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 7 Classification Haveles (pp. 271-272) (Fig. 21-2; Box 21-2) Antineoplastic agents are divided into groups, depending on their mechanism and site of action Alkylating agents contain alkyl radicals that react with DNA in all cycles of the cell to prevent reproduction Antimetabolites attack cells in the S period of reproduction by interfering with purine or pyrimidine synthesis • They are more effective on rapidly proliferating neoplasms cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 8 Classification Miscellaneous antineoplastics Plant alkaloids: mitotic inhibitors and arrest cells in metaphase Antibiotics: cell-cycle nonspecific and are effective for solid tumors Hormones: interrupt the cell cycle at the G stage Steroids: used to suppress lymphocytes in leukemias and lymphomas and in combination therapies Estrogens: used palliatively in operative breast cancer Tamoxifen: used to manage breast cancer Cisplatin: cell-cycle nonspecific Hydroxyurea: inhibits ribonucleotide reductase, which interferes with RNA synthesis Procarbazine: produces chromosomal breakage Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 9 Adverse Drug Effects Haveles (pp. 272-274) Bone marrow suppression Osteonecrosis Gastrointestinal (GI) effects Dermatologic effects Hepatotoxicity Neurologic effects Nephrotoxicity Immunosuppression Germ cells Oral effects cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 10 Adverse Drug Effects Haveles (pp. 272-273) (Table 21-2) Rapidly growing cells are more susceptible to inhibition or destruction by antineoplastic agents Some normal cells have a faster reproductive cycle than slowly growing tumor cells Because cells of the GI tract, bone marrow, and hair follicles are among the faster growing normal cells, early side effects are associated with these tissues cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 11 Adverse Drug Effects Bone marrow suppression: inhibition results in leukopenia or agranulocytosis, thrombocytopenia, and anemia Haveles (p. 273) Symptoms may include susceptibility to infection, bleeding, and fatigue Osteonecrosis: a recently recognized adverse effect of bisphosphonates 94% of all cases of osteonecrosis have been reported in cancer patients receiving intravenous bisphosphonates for multiple myeloma or metastatic carcinoma cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 12 Adverse Drug Effects GI effects: sloughing of GI mucosa can produce many symptoms Haveles (p. 273) May be expressed as nausea, stomatitis, oral ulcerations, vomiting, and hemorrhagic diarrhea Dermatologic effects: cutaneous reactions vary from mild erythema and maculopapular eruptions to exfoliative dermatitis and StevensJohnson syndrome Alopecia is frequent cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 13 Adverse Drug Effects Hepatotoxicity: liver problems occur primarily with antimetabolites Neurologic effects: peripheral neuropathy, ileus, inappropriate antidiuretic hormone secretion, and convulsions have been associated primarily with vincristine or vinblastine cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 14 Adverse Drug Effects Nephrotoxicity: renal tubular impairment occurring secondary to hyperuricemia is caused by rapid cell destruction and release of nucleotides Immunosuppression: enhanced susceptibility to infection or a second malignancy may occur after treatment Germ cells: inhibition is frequent, at least temporarily Mutations within germ cells may occur cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 15 Adverse Drug Effects Haveles (p. 274) (Box 21-3) Oral effects: primarily discomfort, sensitivity of the teeth and gums, mucosal pain and ulceration, gingival hemorrhage, dryness, and impaired taste sensation Infection of oral mucosa from leukopenia and bleeding from thrombocytopenia can occur Patients may experience inflammation of the mouth, xerostomia, or glossitis Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 16 Combinations Haveles (p. 274) Agents with different mechanisms of action are often used together to inhibit the reproduction of neoplastic cells in all phases Mixtures may act synergistically, leading to enhanced cytotoxicity with fewer side effects cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 17 Combinations Haveles (p. 274) Used in lower doses to treat diseases associated with inflammation or autoimmune conditions and transplants Diseases include rheumatoid arthritis, systemic lupus erythematosus, pemphigus vulgaris, and psoriasis Doses of these agents used to treat diseases with an autoimmune component are often lower than the doses used to treat cancer Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 18 Dental Implications Haveles (p. 274) (Boxes 21-3, 21-4) The best times for oral hygiene procedures are when they would coincide with the presence of the highest level of formed blood elements This time frame would be either just before treatment or on the first few days of treatment Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 19 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Alkylating agents Nitrogen mustard • mechlorethamine (Mustargen) • cyclophosphamide, chlorambucil (Leukeran) • melphalan (Alkeran) • uracil mustard • ifosfamide (Ifex) Nitrosoureas • carmustine (BCNU) (BiCNU) • lomustine (CCNU) (CeeNU) • semustine (Methyl-CeeNU) • streptozocin (Zanosar) • estramustine (Emcyt) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 20 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Alkylating Agents Miscellaneous • busulfan (Myleran) • pipobroman (Vercyte) • thiotepa • cisplatin (Platinol) • carboplatin (Paraplatin) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 21 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Antimetabolites Folic acid analog • methotrexate (Amethopterin) Pyrimidine analog • fluorouracil (5-FU) • floxuridine (FUDR) • cytosine arabinoside (ARA-C) (Cytosar-U) • azacitidine Purine analog • mercaptopurine (6-MP) (Purinethol) • thioguanine (6-TG) • cladribine (Leustatin) • fludarabine (Fludara) • pentostatin (Nipent) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 22 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Miscellaneous antineoplastics Plant alkaloids • vinblastine (Velban) • vincristine (Oncovin) Antibiotics • dactinomycin (Actinomycin-D, Cosmegen) • doxorubicin (Adriamycin) • bleomycin (Blenoxane) • mitomycin-C (Mutamycin) • plicamycin (Mithramycin, Mithracin) • daunorubicin (Cerubidine) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 23 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Miscellaneous antineoplastics Hormones • Adrenocorticosteroids (prednisone) • Androgen testolactone (Teslac) fluoxymesterone (Halotestin) • Antiandrogen flutamide (Eulexin) nilutamide (Nilandron) bicalutamide (Casodex) • Estrogen diethylstilbestrol ethinyl estradiol (Estinyl) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 24 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Miscellaneous antineoplastics Hormones • Antiestrogen tamoxifen (Nolvadex) raloxifene (Evista) fulvestrant (Faslodex) toremifene (Fareston) • Aromatase inhibitors anastrozole (Arimidex) exemestane (Aromasin) letrozole (Femara) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 25 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Miscellaneous antineoplastics Hormones • Progestin medroxyprogesterone megestrol (Megace) • goserelin (Zoladex) • leuprolide (Lupron) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 26 Antineoplastic Agents by Group Immune modulators Haveles (p. 272) (Box 21-2) levamisole (Ergamisol) interferon α-n3 (Alferon N) interferon α-2b (Intron A) interferon α-2a (Roferon-A) Podophyllotoxin derivatives etoposide (VePesid) teniposide (Vumon) cont’d… Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 27 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Aminobisphosphonates alendronate (Fosamax) ibandronate (Boniva) pamidronate (Aredia) risedronate (Actonel) zoledronic acid (Zometa) cont’d Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 28 Antineoplastic Agents by Group Haveles (p. 272) (Box 21-2) Other L-asparaginase (Elspar) hydroxyurea (Hydrea) procarbazine (Matulane) paclitaxel (Taxol) altretamine (Hexalen) trastuzumab (Herceptin) imatinib mesylate (Gleevec) Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved. 29