Understanding that CSTDs are not a monolithic category of products is an important priority for pharmacists.Â
Closed-system transfer devices (CSTDs) mechanically prohibit the transfer of environmental contaminants into a system and the escape of hazardous drugs or vapor concentrations outside of the system. Although the first CSTD was approved in the United States in 1998, several products are currently available, including products with widely varying design characteristics.1-3
Because of these design differences, CSTDs are not a monolithic category of products. One of the most important differences between available products is the method of preventing release of hazardous drugs from each device. While some devices rely on a carbon filter to limit the escape of hazardous drug vapors, other devices are mechanically closed. Still, other differences between products may affect real-world use, including the nature of connections.
Some devices rely on a needle-free connector, whereas other devices rely on a needle-based connector between a drug and vials or intravenous bags.2-5
CSTDs and USP <800>
Pursuant to legally binding regulations for the handling of hazardous drugs published by the United States Pharmacopeia (USP)—a regulation known as USP <800>—several practices that are commonplace in pharmacies throughout the United States will change with respect to handling of hazardous drugs. For example, USP <800> requires that pharmacies segregate hazardous drugs and other medications through processes of transport, storage, preparation, and delivery to the patient.4-7
With the eventual implementation of USP <800>, all hospitals and healthcare systems that handle hazardous drugs will eventually have access to CSTDs. USP <800> also recommends but does not require that pharmacies have access to these systems.4-7
Pharmacists must be aware of the differences between available CSTDs, including differences that relate to design characteristics of these products. The important differences between design characteristics of CSTDs may have clinically relevant effects. However, it is difficult to find information about the effects of CSTDs in the design of because these products do not have package inserts. Rather, documentation on CSTDs from the FDA is limited to 510(k) submissions, which provide very limited information.8,9
To help address the gap in knowledge with performance of CSTDs, the National Institute of Occupational Safety and Health (NIOSH) is currently developing a universal protocol that relies on the tile tracer compound 2-phenoxyethanol. This tracer compound may be more amenable to use with filter-based systems, but may not be fully representative of the performance of these systems. Makers of mechanically closed systems have consistently opposed the new “universal” protocol.10,11
Results of NIOSH Testing
A NIOSH draft protocol was tested by Massoomi et al at Ohio Nebraska Methodist Hospital. Researchers tested several CSTDs within an isolated system connected to a real-time testing system continuously sampling for presence of isopropyl alcohol. In these tests, major leaks were detected in all but 2 systems—both mechanically-closed—during procedures stimulating drug transfer for preparation of intravenous medications.
None of the filter-based systems have passed the NIOSH draft protocol, and the protocol even mentioned that it could only be used with mechanically closed systems.10 Importantly, filter-based systems have not consistently performed well under real-world conditions, and as a result have been banned for sale as CSTDs in some European countries, but are marketed in the United States as such.10,11
Understanding that CSTDs are not a monolithic category of products is an important priority for pharmacists, who may be involved in purchasing decisions for these medications, both for their departments and for nursing departments. By using the best available data to choose a device based on performance, it is important for pharmacists to consider results of tests using the draft NIOSH protocol for comparative testing of CSTDs.
Although industry lobbying ultimately defeated official acceptance of the NIOSH protocol, pharmacists and other health care professionals should evaluate all available information to make decisions to protect the health of those who prepare, handle, and administer hazardous drugs every day.