Environmental Contamination with Cyclophosphamide, Ifosfamide, and Methotrexate: A Study of 51 Canadian Centres

Addition of a Novel Qualitative Technique to Standard Quantitative Practices for Evaluation of Hazardous Drug Exposure in a Canadian Hospital Setting

Background

Current recommendations from regulatory authorities suggest quantitative surface sampling for detection of hazardous drugs at least once every 6 months. A more frequent and efficient process for hazardous drug testing might reduce the safety risks associated with exposure to these agents.

Objectives

The primary objective was to assess the findings of surface testing based on traditional quantitative sampling methods relative to the findings of qualitative surface sample testing with the BD HD Check system. The secondary objectives included assessment of the ease of integrating qualitative sampling into pharmacy protocols and identification of opportunities to enhance patient and staff education and safety.

Methods

Samples from 23 unique surfaces were tested concurrently once a month for 5 months using a quantitative surface sampling method and the qualitative BD HD Check system on adjacent 12 inch × 12 inch (30.5 cm × 30.5 cm) surface areas. The presence or absence of cyclophosphamide, methotrexate, and/or doxorubicin contamination was assessed by each of the 2 testing methods. The BD HD Check system was also assessed for ease of use and efficiency.

Results

Ten areas of contamination were identified over the 5-month period. Nine were detected by the BD HD Check system and one by the quantitative system. The BD HD Check system was easy to use, with results available in less than 10 minutes per area tested.

Conclusions

The BD HD Check system allows for more timely identification of surface contamination with hazardous drugs than the standard sampling protocol. The discrepancy in results between the 2 methods of hazardous drug surface sampling requires further investigation.

A simple approach to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings

Background

Several drugs for human use possess genotoxic properties as a necessary consequence of their intended therapeutic effect (e.g. antineoplastics). Health workers may be exposed to these chemicals in various occupational settings such as dose preparation and administration. To date, there are no quantitative risk assessment models to estimate the cancer risk of health workers due to the handling of genotoxic drugs. We therefore developed a quantitative risk assessment model to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings based on the threshold of toxicological concern (TTC) concept. This model was used to evaluate the cancer risk of health workers due to the handling of genotoxic drugs in modern health care facilities.

Methods

We modified the threshold of toxicological concern (TTC) concept to fit the purpose of occupational cancer risk assessment. The risk model underlying ICH guideline M7 (R1): “assessment and control of DNA reactive (mutagenic) impurities in pharmaceuticals to limit potential carcinogenic risk” was used as a starting point for our model. We conducted a short review of studies on the occupational exposure of health workers to genotoxic drugs. These occupational exposure data were compared to the acceptable exposure levels resulting from our TTC based risk model.

Results

Based on the threshold of toxicological concern (TTC) concept, we defined an acceptable daily intake (ADI) of 4 μg/day as threshold of no concern for the exposure of health workers to genotoxic drugs. Regarding the dermal exposure of health workers to genotoxic drugs, we derived a corresponding acceptable surface contamination level (ASCL) of 20 ng/cm². Both ADI and ASCL are usually not exceeded in modern healthcare settings. Current safety precautions provide sufficient protection to health workers.

Conclusions

The application of our model indicates that workers in modern healthcare facilities are not at risk of developing work related cancer above widely accepted cancer risk levels due to the occupational exposure to genotoxic drugs. Hence, the present study may assist employers and public authorities to make informed decisions concerning the need for (further) protective measures and during risk communication to health workers.

Occupational exposure to antineoplastic drugs: what about hospital sanitation personnel?

OBJECTIVE

Occupational exposure to antineoplastic drugs (ANPs) occurs mainly through dermal contact. Our study was set up to assess the potential exposure of hospital sanitation (HS) personnel, for whom almost no data are available, through contamination of surfaces they regularly touch.

METHODS

In the oncology departments of two hospitals around Montreal, surface wipe samples of 120-2000 cm² were taken at 10 sites cleaned by the HS personnel and five other sites frequently touched by nursing and pharmacy personnel. A few hand wipe samples were collected to explore skin contamination. Wipes were analyzed by ultra-performance liquid chromatography tandem-mass spectrometry for 10 ANPs.

RESULTS

Overall, 60.9% of 212 surface samples presented at least one ANP above the limits of detection (LOD). Cyclophosphamide and gemcitabine were most often detected (52% and 31% of samples respectively), followed by 5-fluorouracil and irinotecan (15% each). Highest concentrations of five ANPs were found in outpatient clinics on toilet floors (5-fluorouracil, 49 ng/cm²; irinotecan, 3.6 ng/cm²), a perfusion pump (cyclophosphamide, 19.6 ng/cm²) and on a cytotoxic waste bin cover (gemcitabine, 4.97 ng/cm²). Floors in patient rooms had highest levels of cytarabine (0.12 ng/cm²) and methotrexate (6.38 ng/cm²). Hand wipes were positive for two of 12 samples taken on HS personnel, seven of 18 samples on nurses, and two of 14 samples on pharmacy personnel.

CONCLUSIONS

A notable proportion of surfaces showed measurable levels of ANPs, with highest concentrations found on surfaces cleaned by HS personnel, who would benefit from appropriate preventive training. As potential sources of worker exposure, several hospital surfaces need to be regularly monitored to evaluate environmental contamination and efficacy of cleaning.

Characteristics of wipe sampling methods for antineoplastic drugs in North America: comparison of six providers

Objectives

Several societies have published guidelines to limit the occupational exposure of workers. Several of these guidelines recommend periodic (once or twice a year) environmental monitoring of specific sites where antineoplastic drugs are prepared and administered. However, most of the guidelines provide no guidance concerning which antineoplastic drugs should be monitored, the preferred sampling sites, appropriate test methods or limits of detection. The aim of this study was to characterize providers that quantify antineoplastic drug measured on surfaces.

Methods

This was a cross-sectional descriptive study. To identify service providers offering environmental monitoring tests, we searched the PubMed database and used the Google search engine. We contacted each service provider by email between June 3rd and June 15th, 2020. We specified the objective of our study and described the information needed and the variables of interest with standardized questions. Additional questions were sent by emails or via teleconferences. No statistical analyses were performed.

Results

We identified six providers offering services to Canadian hospitals, either based in Canada or in the United States. Five of these providers were private companies and one was a public organization. Each service provider was able to measure trace contamination of 3–17 antineoplastic drugs. Five of the providers quantified drugs using ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MSMS), which allowed for lower LODs. The sixth provider offered quantification by immunoassay, which has higher LODs, but offers near real-time results; the surface area to be sampled with this method was also smaller than with UPLC-MSMS. The services offered varied among the service providers. The information about LODs supplied by each provider was often insufficient and the units were not standardized. A cost per drug quantified could not be obtained, because of variability in the scenarios involved (e.g. drug selection to be quantified, number of samples, nondisclosure of ancillary costs). Four of the six service providers were unable to report LOQ values.

Conclusions

Few data are available from Canadian service providers concerning the characteristics of wipe sampling methods for antineoplastics. This study identified six north-American providers. Their characteristics were very heterogeneous. Criteria to consider when choosing a provider include the validation of their analytical method, a low limit of detection, the choice of drugs to be quantified and the sites to be sampled, obtaining details about the method and understanding its limits, and price. This should be part of a structured multidisciplinary approach in each center.

Closed-system drug-transfer devices plus safe handling of hazardous drugs versus safe handling alone for reducing exposure to infusional hazardous drugs in healthcare staff

BACKGROUND

Occupational exposure to hazardous drugs can decrease fertility and result in miscarriages, stillbirths, and cancers in healthcare staff. Several recommended practices aim to reduce this exposure, including protective clothing, gloves, and biological safety cabinets ('safe handling'). There is significant uncertainty as to whether using closed-system drug-transfer devices (CSTD) in addition to safe handling decreases the contamination and risk of staff exposure to infusional hazardous drugs compared to safe handling alone.

OBJECTIVES

To assess the effects of closed-system drug-transfer of infusional hazardous drugs plus safe handling versus safe handling alone for reducing staff exposure to infusional hazardous drugs and risk of staff contamination.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, OSH-UPDATE, CINAHL, Science Citation Index Expanded, economic evaluation databases, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov to October 2017.

SELECTION CRITERIA

We included comparative studies of any study design (irrespective of language, blinding, or publication status) that compared CSTD plus safe handling versus safe handling alone for infusional hazardous drugs.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and extracted data. We calculated the risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CI) using both fixed-effect and random-effects models. We assessed risk of bias according to the risk of bias in non-randomised studies of interventions (ROBINS-I) tool, used an intracluster correlation coefficient of 0.10, and we assessed the quality of the evidence using GRADE.

MAIN RESULTS

We included 23 observational cluster studies (358 hospitals) in this review. We did not find any randomised controlled trials or formal economic evaluations. In 21 studies, the people who used the intervention (CSTD plus safe handling) and control (safe handling alone) were pharmacists or pharmacy technicians; in the other two studies, the people who used the intervention and control were nurses, pharmacists, or pharmacy technicians. The CSTD used in the studies were PhaSeal (13 studies), Tevadaptor (1 study), SpikeSwan (1 study), PhaSeal and Tevadaptor (1 study), varied (5 studies), and not stated (2 studies). The studies' descriptions of the control groups were varied. Twenty-one studies provide data on one or more outcomes for this systematic review. All the studies are at serious risk of bias. The quality of evidence is very low for all the outcomes.There is no evidence of differences in the proportion of people with positive urine tests for exposure between the CSTD and control groups for cyclophosphamide alone (RR 0.83, 95% CI 0.46 to 1.52; I² = 12%; 2 studies; 2 hospitals; 20 participants; CSTD: 76.1% versus control: 91.7%); cyclophosphamide or ifosfamide (RR 0.09, 95% CI 0.00 to 2.79; 1 study; 1 hospital; 14 participants; CSTD: 6.4% versus control: 71.4%); and cyclophosphamide, ifosfamide, or gemcitabine (RR not estimable; 1 study; 1 hospital; 36 participants; 0% in both groups).There is no evidence of a difference in the proportion of surface samples contaminated in the pharmacy areas or patient-care areas for any of the drugs except 5-fluorouracil, which was lower in the CSTD group than in the control (RR 0.65, 95% CI 0.43 to 0.97; 3 studies, 106 hospitals, 1008 samples; CSTD: 9% versus control: 13.9%).The amount of cyclophosphamide was lower in pharmacy areas in the CSTD group than in the control group (MD -49.34 pg/cm², 95% CI -84.11 to -14.56, I² = 0%, 7 studies; 282 hospitals, 1793 surface samples). Additionally, one interrupted time-series study (3 hospitals; 342 samples) demonstrated a change in the slope between pre-CSTD and CSTD (3.9439 pg/cm², 95% CI 1.2303 to 6.6576; P = 0.010), but not between CSTD and post-CSTD withdrawal (-1.9331 pg/cm², 95% CI -5.1260 to 1.2598; P = 0.20). There is no evidence of difference in the amount of the other drugs between CSTD and control groups in the pharmacy areas or patient-care areas.None of the studies report on atmospheric contamination, blood tests, or other measures of exposure to infusional hazardous drugs such as urine mutagenicity, chromosomal aberrations, sister chromatid exchanges, or micronuclei induction.None of the studies report short-term health benefits such as reduction in skin rashes, medium-term reproductive health benefits such as fertility and parity, or long-term health benefits related to the development of any type of cancer or adverse events.Five studies (six hospitals) report the potential cost savings through the use of CSTD. The studies used different methods of calculating the costs, and the results were not reported in a format that could be pooled via meta-analysis. There is significant variability between the studies in terms of whether CSTD resulted in cost savings (the point estimates of the average potential cost savings ranged from (2017) USD -642,656 to (2017) USD 221,818).

AUTHORS' CONCLUSIONS

There is currently no evidence to support or refute the routine use of closed-system drug transfer devices in addition to safe handling of infusional hazardous drugs, as there is no evidence of differences in exposure or financial benefits between CSTD plus safe handling versus safe handling alone (very low-quality evidence). None of the studies report health benefits.Well-designed multicentre randomised controlled trials may be feasible depending upon the proportion of people with exposure. The next best study design is interrupted time-series. This design is likely to provide a better estimate than uncontrolled before-after studies or cross-sectional studies. Future studies may involve other alternate ways of reducing exposure in addition to safe handling as one intervention group in a multi-arm parallel design or factorial design trial. Future studies should have designs that decrease the risk of bias and enable measurement of direct health benefits in addition to exposure. Studies using exposure should be tested for a relevant selection of hazardous drugs used in the hospital to provide an estimate of the exposure and health benefits of using CSTD. Steps should be undertaken to ensure that there are no other differences between CSTD and control groups, so that one can obtain a reasonable estimate of the health benefits of using CSTD.

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BACKGROUND

There is increasing evidence that traces of hazardous drugs occur in the urine of health care professionals who are exposed to these drugs.

OBJECTIVE

To review the scientific literature regarding urinary monitoring of health care professionals exposed to antineoplastic drugs through their work.

DATA SOURCES

A search of PubMed using the Medical Subject Headings 'occupational exposure' and 'antineoplastic agents' and of Google Scholar using the terms 'antineoplastic', 'urine', and 'occupational exposure'.

STUDY SELECTION AND DATA EXTRACTION

The analysis covered all articles in English or French pertaining to health care professionals exposed to hazardous drugs in the workplace, published from January 1, 2010, to December 31, 2015. Articles that did not discuss the results of urine tests and those concerning veterinarians, as well as literature reviews, editorials, letters to the editor, and conference abstracts, were excluded.

DATA SYNTHESIS

Twenty-four articles were retained. The studies were conducted in 52 health care institutions in 7 countries. They included 826 workers exposed to hazardous drugs and 175 controls, specifically nurses (n = 16 studies), pharmacists (n = 10), pharmacy technicians (n = 8), physicians (n = 7), health care aides (n = 2), and others (n = 8). Various analytical methods were used to quantify the presence of 13 hazardous drugs, primarily cyclophosphamide (n = 16 studies), platinum-based drugs (n = 7), and alpha-fluoro-beta-alanine, a urine metabolite derived from 5-fluorouracil (n = 3). The proportion of workers with positive results ranged from 0% (n = 10 studies) to 100% (n = 4). Considering only those studies that allowed calculation of the rate of workers with at least one positive urine sample (n = 23), the total proportion was 21% (173/809 workers, for all methods and drugs combined).

CONCLUSION

Twenty-four studies on urine monitoring were conducted in 7 countries between 2010 and 2015. In several studies, no traces of drugs were detected in urine.

Effectiveness of a Closed-System Transfer Device in Reducing Surface Contamination in a New Antineoplastic Drug-Compounding Unit: A Prospective, Controlled, Parallel Study

Background

The objective of this randomized, prospective and controlled study was to investigate the ability of a closed-system transfer device (CSTD; BD-Phaseal) to reduce the occupational exposure of two isolators to 10 cytotoxic drugs and compare to standard compounding devices.

Methods and Findings

The 6-month study started with the opening of a new compounding unit. Two isolators were set up with 2 workstations each, one to compound with standard devices (needles and spikes) and the other using the Phaseal system. Drugs were alternatively compounded in each isolator. Sampling involved wiping three surfaces (gloves, window, worktop), before and after a cleaning process. Exposure to ten antineoplastic drugs (cyclophosphamide, ifosfamide, dacarbazine, 5-FU, methotrexate, gemcitabine, cytarabine, irinotecan, doxorubicine and ganciclovir) was assessed on wipes by LC-MS/MS analysis. Contamination rates were compared using a Chi² test and drug amounts by a Mann-Whitney test. Significance was defined for p<0.05. Overall contamination was lower in the “Phaseal” isolator than in the “Standard” isolator (12.24% vs. 26.39%; p < 0.0001) although it differed according to drug. Indeed, the contamination rates of gemcitabine were 49.3 and 43.4% (NS) for the Standard and Phaseal isolators, respectively, whereas for ganciclovir, they were 54.2 and 2.8% (p<0.0001). Gemcitabine amounts were 220.6 and 283.6 ng for the Standard and Phaseal isolators (NS), and ganciclovir amounts were 179.9 and 2.4 ng (p<0.0001).

Conclusion

This study confirms that using a CSTD may significantly decrease the chemical contamination of barrier isolators compared to standard devices for some drugs, although it does not eliminate contamination totally.