[Evaluation of the Usefulness of Pharmaceutical Outpatient Clinic for Gastric Cancer Patients Receiving Capecitabine plus Oxaliplatin as Postoperative Adjuvant Chemotherapy].

Capecitabine plus oxaliplatin(CapeOX)is widely used as postoperative adjuvant chemotherapy for gastric cancer. The CapeOX regimen often causes digestive symptoms, such as nausea and vomiting under postoperative conditions, and oxaliplatin- induced neurological symptoms, for which supportive intervention is needed. The pharmaceutical outpatient clinic of Jichi Medical University provides pharmaceutical intervention for cancer patients. This study evaluated the usefulness of the pharmaceutical outpatient clinic for gastric cancer patients receiving postoperative adjuvant chemotherapy. The primary endpoint was defined as the effect of the number of outpatient pharmacist interventions on the relative dose intensity of the CapeOX regimen. The secondary endpoint was the correlation between the number of outpatient pharmacist interventions and the worst grade of each side effect. It was observed that patients who received at least 5 outpatient pharmacist interventions had significantly higher dose intensities(p=0.019). Outpatient pharmaceutical interventions were associated with the reduction of side effect symptoms that could be managed with preventive and supportive care. These results showed that continuous intervention by outpatient pharmacists contribute to the optimization of dose intensity and reduction of side effects in gastric cancer patients receiving CapeOX as postoperative adjuvant chemotherapy.

Effect of CYP3A5*3 genetic variant on the metabolism of direct-acting antivirals in vitro: a different effect on asunaprevir versus daclatasvir and beclabuvir.

Direct-acting antivirals, asunaprevir (ASV), daclatasvir (DCV), and beclabuvir (BCV) are known to be mainly metabolized by CYP3A enzymes; however, the differences in the detailed metabolic activities of CYP3A4 and CYP3A5 on these drugs are not well clarified. The aim of the present study was to elucidate the relative contributions of CYP3A4 and CYP3A5 to the metabolism of ASV, DCV, and BCV, as well as the effect of CYP3A5*3 genetic variant in vitro. The amount of each drug and their major metabolites were determined using LC-MS/MS. Recombinant CYP3As and CYP3A5*3-genotyped human liver microsomes (CYP3A5 expressers or non-expressers) were used for the determination of their metabolic activities. The contribution of CYP3A5 to ASV metabolism was considerable compared to that of CYP3A4. Consistently, ASV metabolic activity in CYP3A5 expressers was higher than those in CYP3A5 non-expresser. Moreover, CYP3A5 expression level was significantly correlated with ASV metabolism. In contrast, these observations were not found in DCV and BCV metabolism. To our knowledge, this is the first study to directly demonstrate the effect of CYP3A5*3 genetic variants on the metabolism of ASV. The findings of the present study may provide basic information on ASV, DCV, and BCV metabolisms.