HPE HPE 85 – Spring 2017 - Page 11

Symposium report Issue 85 | Spring 2017 Understanding closed system transfer devices Containment of hazardous drug vapour by closed system transfer devices is critical; new test methods are providing valuable insights into the performance of these devices and recent studies are suggesting new potential applications Christine Clark Freelance Medical Writer The use of closed system transfer devices (CSTDs) should be obligatory whenever cytotoxic or other hazardous drugs are prepared, administered or disposed of, according to Paul Sessink (Managing Director, Exposure Control, Sweden). This is because occupational exposure to cytotoxic drugs poses recognised risks of mutagenicity, carcinogenicity and reproductive toxicity. However, engineering controls, such as biological safety cabinets, do not always provide adequate protection for workers. Studies with CSTDs show substantial reductions of environmental contamination with cytotoxic drugs when the devices are used – and this should reduce potential adverse health effects. A further point to note is that CSTDs are containment devices and the use of such devices has a higher priority in the hierarchy of protection measures than engineering controls, administrative controls and personal protective equipment. Dr Sessink drew attention to a recent publication of the European Biosafety Network, which calls for a common (European) definition of CSTDs, including the technical specifications to be met by a medication transfer system to be considered as a closed system, and harmonised protocols for testing CSTDs. 1 Challenges in selecting a CSTD Selecting a suitable CSTD is not always a straightforward process, explained Jay Brown (Director of Pharmacy Oncology, Specialty and Infusion Services, Novant Health Oncology Specialists, Winston- Salem, North Carolina, US). An ASHP Dr Paul Sessink survey published in 2012 showed that only 21% of health institutions had previously used CSTDs. 2 The available CSTDs are based on several different mechanisms to achieve ‘closedness’ and may not be directly comparable. For example, some rely on a physical barrier or expansion balloon to contain drug vapours or aerosols and others use filtration or air cleaning systems. In addition, different methods of assessment have been used to support claims of being ‘closed systems’. The decision about which CSTD to use may also be driven by outside influences such as the nursing leaders’ views and costs to the institution, he added. United States Pharmacopeia (USP) General Chapter 800 provides standards for safe handling of hazardous drugs to minimise the risk of exposure to healthcare personnel, patients and the environment. It recommends evaluation of existing CSTDs based on published, peer-reviewed data and containment studies. It also requires the use of a CTSD in hazardous drug administration, emphasised Dr Brown. However, it does not require the use of CSTD in compounding of hazardous drugs and it does not guarantee 100% hazardous drug containment through the use of CSTDs. In 2014 the Food and Drug Administration (FDA) created a product code specifically for CSTDs (the FDA ONB code). This define