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Anticancer Drugs

Definition, Purpose, Description, Precautions, Side effects, Interactions

Anticancer, or antineoplastic, drugs are used to treat malignancies, cancerous growths. Drug therapy may be used alone, or in combination with other treatments such as surgery or radiation therapy.

Purpose

Anticancer drugs are used to control the growth of cancerous cells. Cancer is commonly defined as the uncontrolled growth of cells, with loss of differentiation and commonly, with metastasis, spread of the cancer to other tissues and organs. Cancers are malignant growths. In contrast, benign growths remain encapsulated and grow within a well-defined area. Although benign tumors may be fatal if untreated, due to pressure on essential organs, as in the case of a benign brain tumor, surgery or radiation are the preferred methods of treating growths which have a well defined location. Drug therapy is used when the tumor has spread, or may spread, to all areas of the body.

Description

Several classes of drugs may be used in cancer treatment, depending on the nature of the organ involved. For example, breast cancers are commonly stimulated by estrogens, and may be treated with drugs which inactive the sex hormones. Similarly, prostate cancer may be treated with drugs that inactivate androgens, the male sex hormone. However, the majority of antineoplastic drugs act by interfering with cell growth. Since cancerous cells grow more rapidly than other cells, the drugs target those cells which are in the process of reproducing themselves. As a result, antineoplastic drugs will commonly affect not only the cancerous cells, but others cells that commonly reproduce quickly, including hair follicles, ovaries and testis, and the blood-forming organs.

Newer approaches to antineoplastic drug therapy have taken different approaches, including angigenesis— the inhibition of formation of blood vessels feeding the tumor and contributing to tumor growth. Although these approaches hold promise, they are not yet in common use.

Antineoplastic drugs may be divided into two classes: cycle specific and non-cycle specific. Cycle specific drugs act only at specific points of the cell's duplication cycle, such as anaphase or metaphase, while non-cycle specific drugs may act at any point in the cell cycle. In order to gain maximum effect, antineoplastic drugs are commonly used in combinations.

Precautions

Because antineoplastic agents do not target specific cell types, they have a number of common adverse side effects. Hair loss is common due to the effects on hair follicles, and anemia, immune system impairment, and clotting problems are caused by destruction of the blood forming organs, leading to reduction in the number of red cells, white cells, and platelets. Because of the frequency and severity of these side effects, it is common to administer chemotherapy in cycles, allowing time for recovery from the drug effects before administering the next dose. Doses are often calculated, not on the basis of weight, but rather based on blood counts, in order to avoid dangerous levels of anemia (red cell depletion), neutropenia (white cell deficiency), or thrombocytopenia (platelet deficiency.)

Nausea and vomiting are among the most common adverse effects of cancer chemotherapy, and in some cases may be severe enough to cause dose reduction or discontinuation of treatment.

The health professional has many responsibilities in dealing with patients undergoing chemotherapy. The

Anticancer Drugs

Anti Cancer Drugs
Generic (Brand Name) Clinical Uses Common Side Effects To Drug
Altretamine (Hexalen) Treatment of advanced ovarian cancer Bone marrow depression, nausea and vomiting
Asparaginase (Elspar) Commonly used in combination with other drugs; refractory acute lymphocytic leukemia Liver, kidney, pancreas, CNS abnormalities
Bleomycin (Blenoxane) Lymphomas, Hodgkin's disease, testicular cancer Hair loss, stomatitis, pulmonary toxicity, hyperpigmentation of skin
Busulfan (Myleran) Chronic granulocytic leukemia Bone marrow depression, pulmonary toxicity
Carboplatin (Paraplatin) Pallilation of ovarian cancer Bone marrow depression, nausea and vomiting
Carmustine Hodgkin's disease, brain tumors, multiple myeloma, malignant melonoma Bone marrow depression, nausea and vomiting, toxic damage to liver
Chlorambucil (Leukeran) Chronic lymphocytic leukemia, non-Hodgkin's lymphomas, breast and ovarian cancer Bone marrow depression, excess uric acid in blood
Cisplatin (Platinol) Treatment of bladder, ovarian, uterine, testicular, head and neck cancers Renal toxicity and ototoxicity
Cladribine (Leustatin) Hairy cell leukemia Bone marrow depression, nausea and vomiting, fever
Cyclophosphamide (Cytoxan) Hodgkin's disease, non-Hodgkin's lymphomas, neuroblastoma. Often used with other drugs for breast, ovarian, and lung cancers; acute lymphoblastic leukemia in children; multiple myeloma Bone marrow depression, hair loss, nausea and vomiting, inflammation of the bladder
Cytarabine (Cytosar-U) Leukemias occurring in adults and children Bone marrow depression, nausea and vomiting, diarrhea, stomatitis
Dacarbazine (DTIC-Dome) Hodgkin's disease, malignant melanoma Bone marrow depression, nausea and vomiting
Diethylstilbestrol (DES) (Stilbestrol) Breast cancer in post-menopausal women, prostate cancer Hair loss, nausea and vomiting, edema, excess calcium in blood; feminizing effects in men
Ethinyl estradiol (Estinyl) Advanced breast cancer in post-menopausal women, prostate cancer Excess calcium in blood, anorexia, edema, nausea and vomiting; feminizing effects in men
Etoposide (VePesid) Acute leukemias, lymphomas, testicular cancer Bone marrow depression, nausea and vomiting, hair loss

patient must be well informed of the risks and benefits of chemotherapy, and must be emotionally prepared for the side effects. These may be permanent, and younger patients should be aware of the high risk of sterility after chemotherapy.

The patient must also know which side effects should be reported to the practitioner, since many adverse effects do not appear until several days after a dose of chemotherapy. When chemotherapy is self-administered, the patient must be familiar with proper use of the drugs, including dose scheduling and avoidance of drug-drug and food-drug interactions.

Appropriate steps should be taken to minimize side effects. These may include administration of antinauseant medications to reduce nausea and vomiting, maintaining fluid levels to reduce drug toxicity, particularly to the kidneys, or application of a scalp tourniquet to reduce blood flow to the scalp and minimize hair loss due to drug therapy.

Patients receiving chemotherapy are also at risk of infections due to reduced white blood counts. While prophylactic antibiotics may be useful, the health care professional should also be sure to use standard precautions, including gowns and gloves when appropriate. Patients should be alerted to avoid risks of viral contamination, and live virus immunizations are contraindicated until the patient has fully recovered from the effects of chemotherapy. Similarly, the patient should avoid contact with other people who have recently had live virus immunizations.

Other precautions which should be emphasized are the risks to pregnant or nursing women. Because antineo-plastic drugs are commonly harmful to the fetus, women of childbearing potential should be cautioned to use two effective methods of birth control while receiving cancer chemotherapy. This also applies if the woman's male partner is receiving chemotherapy. Breastfeeding should be avoided while the mother is being treated.

Before prescribing or administering anticancer drugs, health care providers should inquire whether the patient has any of the following conditions:

  • chickenpox or recent exposure to someone with chickenpox
  • shingles (Herpes zoster)
  • mouth sores
  • current or past seizures

Anticancer Drugs

Anti Cancer Drugs (continued)
Generic (Brand Name) Clinical Uses Common Side Effects To Drug
Floxuridine (FUDR) Cancers of the liver, pancreas, GI and biliary tract, head and neck tumors See Cytarabine
Fludarabine (Fludara) Chronic lymphocytic leukemia Bone marrow depression, nausea and vomiting, fever
Fluorouracil (5–FU)(Adrucil) Breast, colon, pancreatic cancer, cancer of the rectum and stomach See Cytarabine
Flutamide (Eulexin) Advanced prostate cancer Nausea and vomiting, hot flashes, diarrhea, impotence, decreased libido, gynecomastia
Goserelin (Zoladex) Advanced prostate cancer Pain in bones
Hydroxyurea (Hydrea) Chronic granulocytic leukemia, malignant melanoma Bone marrow depression, gastrointestinal irritation
Idarubicin (Idamycin) Used in combination with other antileukemic drugs, acute myelogenous leukemia See Doxorubicin
Ifosfamide (Ifex) Germ cell testicular cancer Bone marrow depression, nausea and vomiting, inflammation of the bladder
Leuprolide (Lupron) Advanced prostate cancer See Goserelin
Levamisole (Ergamisol) Used in conjunction with Fluorouracil to treat colon cancer Diarrhea, dermatitis, nausea and vomiting
Lomustine Brain tumors, Hodgkin's disease Bone marrow depression, nausea and vomiting, toxic damage to liver
Mechlorethamine (Mustargen) Lung cancer, Hodgkin's disease and non-Hodgkin's lymphomas Bone marrow depression, nausea and vomiting
Medroxyprogesterone (Depo-Provera) Advanced uterine cancer May cause edema
Megestrol (Megace) Advanced uterine cancer, breast cancer Masculinizing effects
Melphalan (Alkeran) Multiple myeloma Bone marrow depression, nausea and vomiting
Mercaptopurine (Purinethol) Acute and chronic leukemias Bone marrow depression, nausea, excess uric acid in blood
Methotrexate (Mexate) Acute lymphoblastic leukemias in children, bone cancer, choriocaricinoma of the testes Bone marrow depression, diarrhea, nausea, stomatitis
  • head injury
  • nerve or muscle disease
  • hearing problems
  • infection of any kind
  • gout
  • colitis
  • intestine blockage
  • stomach ulcer
  • kidney stones
  • kidney disease
  • liver disease
  • current or past alcohol abuse
  • immune system disease
  • cataracts or other eye problems
  • high cholesterol

Other precautions

The anticancer drug methotrexate has additional precautions. Patients should be given advice on the effects of sun exposure and the use of alcohol and pain relievers.

Side effects

Tamoxifen

The anticancer drug tamoxifen (Nolvadex) increases the risk of cancer of the uterus in some women. It also causes cataracts and other eye problems. Women taking this drug may have hot flashes, menstrual changes, genital itching, vaginal discharge, and weight gain. Men who take tamoxifen may lose interest in sex or become impotent. Health care providers should keep in close contact with patients to assess the individual risks associated with taking this powerful drug.

Other anticancer drugs

These side effects are not common, but could be a sign of a serious problem. Health care providers should immediately be consulted if any of the following occur:

  • black, tarry, or bloody stools
  • blood in the urine
  • diarrhea
  • fever or chills
  • cough or hoarseness
  • wheezing or shortness of breath

Anticancer Drugs

Anti Cancer Drugs (continued)
Generic (Brand Name) Clinical Uses Common Side Effects To Drug
Mitomycin (Mutamycin) Bladder, breast, colon, lung, pancreas, rectum cancers, head and neck cancer, malignant melanoma Bone marrow depression, nausea and vomiting, diarrhea, stomatitis, possible tissue damage
Mitotane (Lysodren) Cancer of the adrenal cortex (inoperable) Damage to adrenal cortex, nausea, anorexia
Mitoxantrone (Novantrone) Acute nonlymphocytic leukemia Cardiac arrhythmias, labored breating, nausea and vomiting, diarrhea, fever, congestive heart failure
Paclitaxel (Taxol) Advanced ovarian cancer Bone marrow depression, hair loss, nausea and vomiting, hypotension, allergic reactions, slow heart action, muscle and joint pain
Pentastatin (Nipent) Hairy cell leukemia unresponsive to alpha-interferon Bone marrow depression, fever, skin rash, liver damage, nausea and vomiting
Pipobroman (Vercyte) Chronic granulocytic leukemia Bone marrow depression
Plicamycin (Mithracin) Testucular tumors Toxicity/damage to bone marrow, kidneys, and liver
Prednisone (Meticorten) Used in adjunct therapy for palliation of symptoms in lymphomas, acute leukemia Hodgkin's disease May be toxic to all body systems
Procarbazine (Matulane) Hodgkin's disease Bone marrow depression, nausea and vomiting
Streptozocin (Zanosar) Islet cell carcinoma of pancreas Nausea and vomiting, toxicity to kidneys
Tamoxifen (Nolvadex) Advanced breast cancer in post menopausal Nausea and vomiting, ocular toxicity, hot flashes
Teniposide (Vumon) Acute lymphocytic leukemia in children See Etoposide
Vinblastine (Velban) Breast cancer, Hodgkin's disease, metastatic testicular cancer Bone marrow depression, neurotoxicity
Vincristine (Oncovin) Acute leukemia, Hodgkin's disease, lymphomas Constipation, neurotoxicity, possible tissue necrosis
  • sores in the mouth or on the lips
  • unusual bleeding or bruising
  • swelling of the face
  • red "pinpoint" spots on the skin
  • redness, pain, or swelling at the place on the body where an injectable anticancer drug is given
  • pain in the side or lower back
  • problems urinating or painful urination
  • dizziness or faintness
  • fast or irregular heartbeat

Other side effects do not need immediate care, but should have medical attention. They are:

  • joint pain
  • skin rash
  • hearing problems or ringing in the ears
  • numbness or tingling in the fingers or toes
  • trouble walking or balance problems
  • swelling of the feet or lower legs
  • unusual tiredness or weakness
  • loss of taste
  • seizures
  • dizziness
  • confusion
  • agitation
  • headache
  • dark urine
  • yellow eyes or skin
  • flushing of the face

In addition, there are other possible side effects that do not need medical attention unless they persist or interfere with normal activities. These include changes in menstrual period, itchy skin, nausea and vomiting, and loss of appetite.

Other rare side effects may occur. Anyone who has unusual symptoms after taking anticancer drugs should contact the physician who prescribed the medication.

Interactions

Anticancer drugs may interact with a number of other medicines. When this happens, the effects of one or both of the drugs may change or the risk of side effects may be greater. The health care provider should be aware of all other prescription or non-prescription (over-thecounter) medicines a patient is taking. The primary care provider should also be told if the patient has been treated with radiation or has taken other anticancer drugs.

Samuel Uretsky, PharmD

KEY TERMS


Cataract—Clouding of the lens of the eye, leading to poor vision or blindness.

Impotent—Unable to achieve or maintain an erection of the penis.

Additional topics

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