Timing of Naldemedine Initiation and Occurrence of Diarrhea in Patients Receiving Strong Opioid Analgesics: A Retrospective Study.

Naldemedine, a peripherally acting μ-opioid receptor antagonist, is used to treat opioid-induced constipation (OIC). However, it causes diarrhea as an adverse effect. This retrospective study aimed to investigate whether the occurrence of diarrhea was dependent on the timing of naldemedine treatment initiation. Inpatients who were initially treated with naldemedine at the Department of Respiratory Medicine, NHO Iwakuni Medical Center, Japan, between 1 December 2017 and 31 March 2021 were included in this study and divided into the simultaneous combination group, in which naldemedine was introduced at the same time as strong opioid analgesics, and the non-simultaneous combination group, in which naldemedine was introduced after the initiation of treatment with strong opioid analgesics. This study included 45 patients, 15 (33.3%) of whom developed diarrhea. Among the patients in the simultaneous combination group and non-simultaneous combination group, diarrhea occurred in 2 (11.1%) and 13 (48.1%) patients, respectively. Multivariate logistic regression analysis revealed that the delayed introduction of naldemedine was significantly associated with the development of diarrhea (odds ratio: 6.68, 95% confidence interval: 1.220-36.700, p = 0.028). Our analysis reveals that the simultaneous administration of naldemedine and oxycodone may prevent the development of diarrhea associated with naldemedine use for OIC.