Purpose: To identify risk factors for opioid-induced constipation (OIC).Methods: This study retrospectively analysed 175 advanced cancer patients who were receiving pain treatment with opioids and were newly prescribed laxatives for OIC at Seirei Hamamatsu General Hospital between November 2016 and June 2021. For the regression analysis of factors associated with OIC, variables were extracted manually from medical charts. The effect of laxatives was evaluated 3 days after administration. The effect of laxatives was evaluated based on whether the OIC was improved. The OIC was de ned based on Rome IV diagnostic criteria. Multivariate ordered logistic regression analysis was performed to identify risk factors for OIC. Optimal cut-off thresholds were determined using receiver operating characteristic analysis. Values of P < 0.05 (two-tailed) were considered signi cant.Results: Signi cant factors identi ed included body mass index (BMI)

Background Opioid-induced constipation (OIC) is one of the most common adverse events of opioid therapy and can severely reduce quality of life (QOL). Naldemedine is the orally available peripheral-acting μ-opioid receptor antagonist approved for OIC treatment. However in daily clinical practice, some cancer patients show insufficient control of OIC even while receiving naldemedine. Objective To identify factors associated with non-response to naldemedine in cancer patients. Methods This study retrospectively analyzed 127 cancer patients prescribed naldemedine at Seirei Hamamatsu General Hospital in Japan between November 2016 and June 2021. For the regression analysis of factors associated with OIC, variables were extracted manually from electronic medical records. Naldemedine had been prescribed by the attending physician after the presence of OIC had been defined with reference to Rome IV diagnostic criteria. Naldemedine was evaluated as “effective” in cases where the number of defecations increased at least once in the first 3 days after starting naldemedine. Multivariate logistic regression analysis was performed to identify factors associated with non-response to naldemedine. The data used were from the group of patients who received naldemedine in our previous study. Results Factors significantly associated with non-response to naldemedine included chemotherapy with taxanes within 1 month of evaluation of naldemedine effect (odds ratio [OR] = 0.063; 95% confidence interval [CI] = 0.007–0.568), and addition of or switching to naldemedine due to insufficient efficacy of prior laxatives (OR = 0.352, 95% CI = 0.129–0.966). Conclusion The identification of factors associated with non-response to naldemedine prescribed for OIC may help improve QOL among cancer patients.

Occasionally, we have experienced cases of patients with mild articulating pain who have been introduced to opioids. We considered the possibility that physician assessment alone might be insuf cient. We developed and examined the usefulness of a system that helps pharmacists perform a pain assessment prior to consultation and suggest prescriptions for analgesics.From March 1, 2020 to December 31, 2020, the number of prescription suggestions and the rate at which they were adopted were investigated in patients who were instructed before opioid introduction. The number of patients instructed was 226, whereas the number of prescription suggestions was 231, with an adoption rate of 98.3％. The 23 patients who did not use opioids showed signi cantly improved mean pain scores, from a median NRS of 3 -2 (P = 0.0123), with the most intense pain decreasing from a median NRS of 7 -5 (P = 0.0154). We believe that pain assessment before opioid induction facilitated the selection of an appropriate analgesic. However, among the nine patients who were instructed after opioid introduction, two expressed minor pain. We believe that the pharmacist's prescription suggestion, which is tailored to the patientʼs life background and general condition, promoted the selection of an appropriate analgesic.In conclusion, pharmacists should evaluate pain and prescription suggestions before introducing opioids as a strategy to support medical treatment and promote appropriate opioid use, thereby suggesting their active utilization in clinical practice throughout Japan.