Cytotoxic drugs were developed from mustard gas used in the First World War. Up until 1980 there were very few safety standards in place with regards to hazardous drug handling. Pharmacists were using only gloves, masks and gowns for protection when manipulating these drugs. Horizontal laminar flow hoods were in use in some places at that time.
It was reported by the University of Helsinki that traces of chemotherapeutic agents had been found in the urine of oncology nurses. Shortly after that, in the early 80s, nurses began to report that they were experiencing side effects similar to those of chemotherapy patients, such as nausea, vomiting, hair loss and mouth sores (Source: NITA 1980) The hospitals began to take notice and to perform studies to identify the cause of the problems. They found that there was mutagenic activity in personnel working in the horizontal laminar air flow hoods. Based on these findings, vertical laminar flow hoods were implemented as the new standard in safe handling of hazardous drugs.
During the 1990s through the early 2000s several wipe studies were published and consistently reported similar results. Regardless of how careful and skilled employees were, contamination was still a problem. Because of the recurring finding, in the mid-90s OSHA (1996) set out this statement on the potential hazards of handling antineoplastic and cytotoxic drugs:
“Preparation, administration and disposal of hazardous drugs, may expose pharmacists, nurses, physicians and other health care workers to potentially significant workplace levels of these chemicals.”
The result of these studies showed that contamination was found in approximately 75% of samples taken from pharmacy areas such as laminar hoods, the floor of the preparation area, the work surface inside the hood and pharmacists’ shoes, gloves and gowns. It was also found that approximately 65% of the administration areas were contaminated. This included the floor around the patient’s chair, the office telephone, the patient’s bed and the top of the preparation area and trays.
It has been found that coming into contact with these hazardous agents could cause numerous problems. These problems ranged from skin irritations to leukemia. Also there were effects on reproductive health; contaminated health care workers experienced higher rates of spontaneous abortions and potential fetal malformations. Workers would report that they were experiencing side effects similar to those of a chemotherapy patient (hair loss, vomiting, mouth sores, and skin rashes). Additionally, the incidence of cancer in these workers was higher, especially for leukemia and bladder cancer.
The World Health Organization estimates that there will be a 50% increase in cases of cancer over the next 20 years. One factor that is likely to contribute to this increase is the widespread use of increasingly potent chemotherapeutic agents to fight cancer. This means that the risk of exposure to these hazardous drugs will increase. Moreover, because of continued research and development, hazardous drugs are now being used for non-malignant illnesses and experimental and investigational purposes as well.
The IARC (International Agency for Research on Cancer) says that there are at least 10 (Group I) drugs plus 2 (Group I) drug combination therapies in use today that are PROVEN to be carcinogenic to humans. They have also found that there are at least 9 Group IIa drugs that are probably carcinogenic to humans. Finally, at least 10 more Group IIb drugs are possibly carcinogenic to humans when handled. Moreover, there are at least 138 drugs that are defined as hazardous by NIOSH and ASHP guidelines.
The IARC classifications are based on reported data and as new reports become available, a drug can be moved to a more hazardous classification level.
IARC Group I Proven human carcinogen 10 drugs & 2 combination therapies
IARC Group II A Probable human carcinogen 9 drugs
IARC Group II B Possible human carcinogen 10 drugs
Because of ongoing research and emerging evidence, hazardous drugs are now being explored and used for a number of conditions including rheumatoid arthritis, systemic lupus erythematosus (SLE), human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). They are also being used in areas where they have not traditionally been used, such as operating theatres (operating room, OR) and radiology departments.
Contamination is commonly reported on the following surfaces: biologic safety cabinet (BSC) work surfaces, BSC hood, BSC airfoil, preparation room floor, gloves , gowns, shoes, pharmacy floor, pharmacy office chair, syringes, carts, trash cans, patient´s room floor, patient´s table, patient´s chair and check-in counters in the IV room. Contamination can be found dispersed in the environment anywhere that hazardous drugs have been used.
The obvious route of exposure would be accidental drug spillage resulting in skin contact, absorption and inhalation.
Dermal contact can be made by direct contact with the drugs as well as by touching contaminated surfaces. Absorption or the ingestion of drugs was found as a result of from hand-to-mouth exposure, through eating, drinking and chewing gum whilst handling cytotoxic agents. Inhalation exposure occurs when people breathe contaminated air (aerosols and vapors). Pressurization of the vial and the open, wet connections very often result in aerosol formation and vaporization of the drugs. It is known that many chemotherapy drugs evaporate at room temperature.
Hospital workers, mainly nurses, pharmacists, pharmacy technicians, physicians and nursing aides are potentially at risk. There are also reported cases of human uptake of chemotherapeutic agents in staff who are not involved in handling drugs themselves, but work in the areas where hazardous drugs are handled.
