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Even a little exposure to some hazardous drugs can be highly absorbed.
Even a little exposure to some hazardous drugs can be highly absorbed.
A number of health care providers have wondered if their lax attitudes toward chemotherapy toxicities may have contributed to cancers they are currently fighting. Many of these same workers were trained before the routine use of chemo hoods, gowns, or even gloves, and held the attitude that a little skin exposure was insignificant—an attitude that is still pervasive in the medical community today.1 Concerns about occupational exposures to antineoplastics began in the 1970s,2 and although safety practices have improved with time, chemotherapy residue continues to contaminate workplaces.3 Pharmacists continue to handle many known carcinogens, and even a little exposure to some of these hazardous drugs can be highly absorbed.3 One pharmacist’s last wish was that health care workers take these exposures more seriously.1
About 8 million health care workers are potentially exposed to hazardous drugs at work. Pharmacists and nurses have the highest exposure risk, but many other hospital staff and some veterinary workers also have chances for exposure.3,4 Anyone who may handle bodily fluids or chemotherapy waste products has a potential for exposure.3
In a teaching hospital where protective equipment was used most of the time (over 98% of chemotherapy preparation jobs, 62% of administrations and patient contacts, and 53% of hood cleanings), staff still reported acute symptoms consistent with hazardous drug exposure, such as eye and nose irritation, headache, and metallic taste.5 Skin reactions were the most frequently reported adverse events (AEs), but central nervous system, respiratory, vision, and gastrointestinal reactions were also common.5
In a hospital pharmacy, where “adequate” standard procedures for handling and administering hazardous drugs, such as the use of double chemotherapy gloves and disposable gowns, were in place but not always followed, chemotherapy residue was found in expected and unexpected places.6 Not surprisingly, levels were high in the chemotherapy hood, but detectable levels were also found on the computer touch screen, in front of the pharmacist’s keyboard, on the inner doorknob of the pharmacy, where mixed IVs were kept, in the vehicle used to transport unopened chemotherapy to the pharmacy, and on the outside of unopened chemotherapy bottles, with the highest levels found in the cabinet where chemotherapy drugs were stored.6
Other studies have also found widespread external contamination of chemotherapy vials, well above the minimum level of detection.7 A joint letter sent to US hospitals from the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety & Health Administration (OSHA), and The Joint Commission cautioned workers who can be exposed to powerful chemotherapy agents, antivirals, hormones, and others drugs that are “known to cause cancer, reproductive, and developmental problems; allergic reactions; and other AEs that can be irreversible even after low-level exposures” about the need for safe practices.4
What Makes a Drug Hazardous?
Although antineoplastics are the primary focus of OSHA guidelines for handling hazardous drugs, other drugs covered under the guidelines are also considered hazardous because of their potency (only small quantities needed for effects) or irreversibility.2
NIOSH deems drugs as being “hazardous” based on 5 characteristics: carcinogenicity, teratogenicity (developmental toxicity), reproductive toxicity, organ toxicity at low doses, and genotoxicity.2 In their evaluation, any available human data are considered significant, but lacking that, NIOSH takes into account animal results, with more weight given to factors such as multiple species events, multiple organ effects, and whether effects occurred at or below the maximum recommended human dose (MRHD); results far above the MRHD are not considered relevant.
For genotoxicity, in vivo data are given more weight than in vitro data, but multiple in vitro results, and fetal effects without maternal toxicity, are considered relevant. Pregnancy category X drugs are usually deemed hazardous, but some D and C drugs are also included, often because of concomitant toxicities. Drugs with safe handling guidelines from the manufacturer are automatically deemed hazardous.2
While many chemotherapy agents damage DNA, other drugs, including some antivirals, antibiotics, and bioengineereds, affect cell growth, proliferation, or DNA synthesis.2 Per the FDA, a bioengineered drug is “any plant manipulated by recombinant DNA technology to express a gene encoding a biological or drug product.”9 Some drugs have nonselective action, which affects both healthy and diseased cells, resulting in toxic side effects for patients and potential side effects for exposed health care workers.2 Acute effects from chemotherapy exposure include nausea, rashes, alopecia, renal and hepatic damage, hearing loss, and cardiac and hematopoietic toxicities.3 Potential long-term effects include bone marrow damage, heart and lung damage, infertility, embryofetal effects, and cancer.3
The NIOSH list of hazardous agents primarily includes antineoplastics, but also androgens, immunosuppressants, antivirals, anticonvulsants (phenytoin, carbamazepine, zonisamide), and gonadotropins, as well as some psychoactive medications (risperidone, ziprasidone, clonazepam).2 Surprises on the list include colchicine and rasagiline for their pregnancy ratings, and risperidone for evidence of tumors at a low dose. Most are on the list because of their carcinogenic properties, even at low doses, but many others are included for their reproductive and developmental toxicities.
Some medications are not hazardous in their typical intact formulations (tablets, capsules), but become hazardous when they are altered (eg, broken, crushed) and should therefore be handled cautiously. A prime example is finasteride: although the tablets are coated, the drug may be absorbed when broken, and women who may even potentially become pregnant should not handle broken tablets.10 An AUC as low as 0.1 mg/kg/day (0.03 MRHD) can cause abnormalities of the male external genitalia.10
What Can I Do About It?
Exposure is mostly by inhalation and dermal absorption, but can also happen via sharps injuries, accidental ingestion after touching contaminated surfaces, or vapors.6 OSHA recommends handling intact tablets and capsules with gloves, and most other forms (eg, broken tablets, powders, liquids, topicals) with at least double gloves, a protective gown, eye protection, and respiratory protection or use of a hood.2 Studies have found that the use of improved decontamination procedures plus protective sleeves reduced contamination levels 90%.7
Employers are encouraged to take an active role in evaluating their workplace for hazards, making sure safety equipment is in place and in educating their staff regarding its proper use—a process requiring continual improvement.8 Training should cover anyone who may be exposed, from pharmacists and nurses directly handling medications to the janitorial staff who may have to clean up contaminated fluids and linens.6 To improve the situation, employers could require use of gowns, gloves, and safety goggles (rather than just prescription glasses); update safe drug handling procedures; make sure all employees who may handle chemotherapy drugs are trained; and encourage employees to report all concerns and work-related illnesses.6 Although NIOSH has a list of hazardous drugs (www.cdc.gov/niosh/ docs/2010-167/),8 it cannot keep up with new approvals, so employers are encouraged to create their own site-specific lists of hazardous materials and how they should be handled.2 Employees can help themselves by using all required personal protective equipment, even when it’s uncomfortably warm.6
A recent study from the Centers for Disease Control and Prevention showed that chemotherapy contamination in the workplace continues; it has even been found in the urine of some who handle it, despite available safety precautions.1 Even in a hospital pharmacy where adequate standard procedures were in place for handling and administering hazardous drugs—such as using double chemotherapy gloves and disposable gowns— but not always followed, chemotherapy residue was found in expected and unexpected places.6
Many still think a little bit of exposure isn’t a problem. Those who used to feel that way wish for everyone to learn from their experiences and be careful around chemotherapy agents.1
Debra Freiheit has been a practicing pharmacist and human services professional for over 25 years. Specializing in medical information, she has compiled a broad spectrum of experience obtained through research for companies including Cerner and PPD Inc. With an emphasis on clear and concise information transfer, she has built a career communicating data with medical professionals and patients. Education and knowledge have been her motivation for a rich career of caregiving through research. Debra’s current project involves the creation of a multinational database of drug information.
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