1603P - The relationship between naldemedine administration and the maximum dose of oral opioids

Opioid-induced constipation (OIC) is the most common side effect of opioid therapy. Laxatives are usually used as a first-line treatment option for OIC. Treatment options for OIC are switching to other opioids associated with less frequent OIC, such as Fentanyl. Naldemedine is an orally active peripherally acting µ-opioid receptor antagonists that was approved in Japan from 2017 for management cancer-related OIC. The aim of this study is to investigate the relationship between Naldemedine administration and the maximum dose of oral Oxycodone which is the oral opioids used most at our hospital. During June 2017 and December 2018, a total of 217 patients with cancer-related pain received Oxycodone at our institution. The first group of the patients concurrently received Naldemedine 0.2mg daily (group A, n=100) and the second group didn’t receive (group B, n=117) for cancer-related OIC reduction. We compared the maximum Oxycodone dose between two groups by medical recode retrospectively. The median age of group A was 69 y.o. (range 20-87 y.o.), and the median age of group B was 67 y.o. (range 27-88y.o.). There was no significant difference in common patient background between group A and B. The median dose of maximum Oxycodone dose of group A was 40mg/day (range 10-480mg/day), and the median dose of maximum Oxycodone dose of group B was 20mg/day (range 10-320mg/day). There was a significant difference (Mann-Whitney U test, P