Pharmacists’ recommendations on the drug-drug interaction between precipitated calcium carbonate and gastric secretion inhibitors

Abstract

Hyperphosphatemia is associated with vascular calcification and prognosis. Therefore, controlling serum phosphate concentrations at the early predialysis chronic kidney disease (CKD) stages is important. Precipitated calcium carbonate is mainly used to control serum phosphate concentrations of individuals with CKD, especially in Japan; however, it interacts with gastric secretion inhibitors and may affect vascular calcification. Necessarily, this has to be considered before prescribing, but is not pervading clinically. In this study, pharmacists in our hospital provided information about the drug-drug interaction and its vascular risk to physicians treating individuals with predialysis CKD meeting the following criteria in January 2014: 1) serum phosphate concentration >4.5 mg/dL, 2) using precipitated calcium carbonate and a gastric secretion inhibitor. Seven individuals met these criteria, which the pharmacists reported to the attending physicians; all prescription pattern changes were recorded. The prescription of 5 out of 7 individuals was changed; the precipitated calcium carbonate and/or gastric secretion inhibitor was discontinued. Providing this information also decreased the combination prescription rate in the entire hospital from 75% to 21%. We also surveyed physicians on the clinical benefits of information provision by pharmacists. Four out of 6 physicians answered that they were not aware of this specific drug-drug interaction. All physicians answered that the information provided affected the prescription policy for individuals with predialysis CKD.Our results indicate that pharmacists’ recommendations affect prescription patterns, and that physician-pharmacist collaborations may contribute to improving the efficacy and safety of pharmacotherapy in various therapeutic areas.