Pilot assessment of the antineoplastic drug contamination levels in British Columbian hospitals pre- and post-cleaning

Abstract

Objective. We undertook a pilot study involving six British Columbian hospital pharmacies to determine if antineoplastic drug contamination of surfaces exists and whether residual drugs remain on these surfaces despite being cleaned.

Methods. At each site, the pharmacy technician responsible for preparing the antineoplastic drugs was observed to determine which surfaces were contacted and to ascertain the frequency of contact. Surfaces observed to be most frequently contacted were subsequently wiped after drug preparation pre- and post-clean. The wipe samples were then analyzed by liquid chromatography tandem mass spectrometry to determine the amount of contamination. Cyclophosphamide (CP) and methotrexate (MTX) were used as representative markers to reflect overall antineoplastic drug contamination levels.

Results. Fourteen of the 23 surfaces sampled pre-clean (61%) were contaminated with either MTX or CP. The pre-clean wipe samples had a geometric mean concentration of 0.0135 ng/cm² for MTX (range <Limit of Detection {LOD} to 12.45 ng/cm²) and 0.114 ng/cm² for CP (range <LOD to 8.53 ng/cm²). Post-clean contamination levels were generally lower than its pre-clean equivalent; the concentration difference post- vs. pre-clean was statistically significant for CP only. However, some samples appeared to have higher post-clean contamination levels.

Conclusions. The results suggest that drug contamination is common in hospital pharmacies we sampled and that current cleaning practices in British Columbia may not be effective in removing residual drug from the surfaces. A more extensive study is recommended to confirm these results as well as a review of cleaning protocols to ensure their effectiveness in reducing contamination levels.