Objectives: This study aimed to find working conditions related to internal exposure of substances handled in centralised cytostatic drug preparation units in hospitals. Recommendations to avoid this uptake should be deduced from the results.
Method: In a longitudinal study over 3 years, 87 pharmacy technicians and pharmacists of 14 different hospitals in Germany provided 24-h urine samples separately up to three times (three sampling cycles: cycles 1-3) at the end of a working week. Additional samples were taken after 2 days and after at least 3 weeks of absence. Cyclophosphamide and ifosfamide, doxo-, dauno- epi-, and idarubicin, and platinum deriving from cis- and carboplatin were determined in urine samples by gas chromatography/mass spectrometry, liquid chromatography (HPLC) and voltammetry. The following working conditions were assessed by questionnaire: working tasks, different ways that the workbenches were run, cleaning conditions, waste disposal, number of preparations, amount of substances handled, and use of gloves (material, thickness and changing interval).
Results: Two-thirds of the subjects showed at least one positive result with regard to all three cycles (56 of initially 87 subjects). Employees who only pass material that is needed for processing are affected, just as are those who only prepare administrations and those alternating in both functions (25% vs. 24.1% vs. 50.6%, respectively). The storage of waste in containers that could be opened to add waste tends to increase the risk of internal exposure of ifosfamide and cyclophosphamide (odds ratios (95% confidence interval): 0.08 (0.013-0.5) and 0.19 (0.03-1.12), respectively). The amount handled and number of preparations of cyclophosphamide for "manufacturers" were associated with internal exposure of cyclophosphamide (28.04 (1.75-448.74) and 1.22 (1.03-1.44), respectively). The total number of preparations handled by assistants seemed to increase the risk of intake of any of the substances under study [1.04 (1.00-1.08)].
Conclusion: Since employees who pass materials are affected in the same way as those who prepare administrations, both have to be included in reviewing protective measures. Further studies must be carried out to verify the generated hypotheses of factors related to internal exposure found in this study.