4CPS-077 Detection and communication of concomitant use of capecitabine and proton pump inhibitors

Background and importance Recent data suggest that the concurrent use of proton pump inhibitors (PPI) may reduce the efficacy of capecitabine by decreasing its absorption. It was associated with poorer progression free survival (PFS) and overall survival in a secondary analysis of the TRIO-013 trial. Univariate analysis of a retrospective study of patients treated with capecitabine for colorectal cancer found that PPI use was associated with a decrease in 5 year PFS. Although the authors concluded that a significant interaction exists, after multivariate analysis, PPI use was no longer associated with worse PFS. No interaction was observed with magnesium–aluminium hydroxide containing antacid. According to this, the probability of interaction may be doubtful. However, because the possible outcome may be serious, we suggested an intervention to alert oncologists. Aim and objectives A protocol was implemented to detect the concurrent use of PPI in outpatients treated with capecitabine and to communicate the drug interaction to oncologists. The aim of this study was to describe the pharmacist intervention and its results. Material and methods Pharmacists developed the following protocol: (1) Identification of patients treated with capecitabine and PPI: pharmacists actively reviewed the electronic clinical records for the presence or absence of PPI prescriptions for each patient treated with capecitabine. (2) Designing an informative note: the note included information about the possible drug interaction and patients identified in the previous phase. We recommended monitoring the effectiveness of capecitabine, routinely ascertaining the need for PPI use and PPI suspension or replacement with an alternative antacid treatment, whenever possible. (3) Diffusion of the information to oncologists via email. Results Over 1 year, we detected 71 patients treated with capecitabine, of whom 46 (65%) presented concomitant use of PPI (78% omeprazole, 13% pantoprazole, 7% esomeprazole and 2% rabeprazole). The reasons for capecitabine prescription were: 52% colorectal, 24% gastric or oesophageal, 13% breast and 11% pancreatic cancer. In all patients, monitoring the effectiveness of capecitabine was the preferred option. Conclusion and relevance Most patients treated with capecitabine were also receiving treatment with PPI. In our case, oncologists preferred to monitor the effectiveness of capecitabine rather than discontinue PPI. This study reflects how pharmacists, as part of the multidisciplinary team, can participate in achieving better health outcomes. References and/or acknowledgements No conflict of interest.