Cancer and cytotoxic agents used in its treatment

Cancer, or neoplastic diseases, involves abnormal tissues (neoplasm) that grow excessively through uncontrolled cell division (Figure 9-1). They can metastasize or invade the surrounding healthy tissues and cells interfering with their function. Antineoplastic drugs, also referred to as chemotherapy agents, are used to either destroy these cells or control their growth.

Chemotherapy drugs are designed to affect cells that divide and grow rapidly. Since the malignant cells have these fast-growing properties and a high metabolic rate, the chemotherapy drugs affect them more. However, cells of the oral mucosa, gastrointestinal tract, bone marrow, and lymph tissues also grow rapidly and are affected by these drugs as well. This is the main disadvantage of using these agents; they destroy normal cells as well as the cancer cells. If too much damage is done to the normal cells before the cancer is brought under control, sometimes withdrawal of treatment must occur.

There are also many side effects and complications associated with these drugs, such as severe pain, nausea and vomiting, hair loss, and a compromised immune system. Patients often have to receive additional supportive agents, such as epoetin alfa (Epogen, Procrit), to prevent chronic anemia that occurs due to the use of chemotherapy agents. These supportive agents are hormones that help to rebuild red blood cells that have been destroyed due to the medication. Since the chemotherapy medications are considered toxic or hazardous, special considerations must be observed when preparing them aseptically.

Preparation of chemotherapy agents

Aseptic technique should be followed when preparing any IV admixture, but when handling hazardous or cytotoxic agents, there are additional precautions. American Society of Health-System Pharmacists (ASHP) and USP 797 have specific guidelines concerning hazardous drugs and include special procedures, disposal, storage, and delivery of the medication to prevent unnecessary exposure. Occupational exposure can result in skin rashes, adverse reproductive effects, and even cancer. Drugs should be prepared in a biological safety cabinet (BSC) or compounding aseptic containment isolator (CACI). This special hood takes air in at the top where it passes through a HEPA filter and is then directed downward toward the work surface. The downward direction of the air does not expose the operator to the air as does the outward flow of air in a horizontal laminar airflow workbench (LAFW) hood. The air should be 100% vented to the outside air though HEPA filtration according to USP 797 guidelines. This BSC should also be placed physically away from the other preparation areas and allowed to remain running twenty-four hours a day.

Often a large hospital will have a separate department for chemotherapy infusion where this may be accomplished. Gowns, face masks, eye protectors, hair covers, shoe covers, and double gloving with special sterile chemo-type gloves is required during the preparation of all hazardous materials. A special sharps container marked with “CAUTION: BIOHAZARDOUS WASTE” or “CHEMOTHERAPY WASTE” should be placed in the BSC and used as well. Red disposal bags or biohazard bags for trash should be used instead of the regular trash bags. Place all waste generated in the BSC in a small sealed plastic bag before removing it from the BSC. A special leak-proof absorbent pad should be placed on the work surface of the BSC to catch any small spills that may occur during manipulations. Only necessary items used in the preparation of the admixture should be placed in the BSC, because any items exposed to open vials or ampules must be disposed of in the hazardous waste bags.