A Survey of the Incidence of Constipation in Patients with Chronic Non-cancer Pain Using Opioid Analgesics in Japan

INTRODUCTION: Although opioids have potent analgesic properties, their use is associated with side effects, including opioid-induced constipation (OIC). This study investigated the incidence of OIC based on the Rome IV diagnostic criteria in patients using opioid analgesics for chronic non-cancer pain and to explore and compare the risk factors for the development of OIC in opioid analgesic users. METHODS: We surveyed patients aged 20 years or more living in Japan via the internet; who had been using opioid or non-opioid analgesics (N = 500 each) for at least 3 months for relief from chronic non-cancer musculoskeletal pain (low back pain or osteoarthritis); and who provided electronic consent to participate in and complete the survey. The groups were matched for age and sex. RESULTS: Of the patients using opioid analgesics, 89% were taking weak opioids. The proportion of patients perceiving constipation was comparable between the opioid and non-opioid analgesic groups (34% vs 29%, respectively); however, a significantly higher proportion of patients in the opioid group, compared to the non-opioid group, reported self-assessed constipation (40% vs 18%, respectively) after using an analgesic and fulfilled two or more symptoms of the Rome IV diagnostic criteria for constipation (28% vs 19%, respectively). A higher proportion of patients were taking prescribed medicine for constipation in the opioid group compared with the non-opioid group (33% vs 18%, respectively). Low back pain, but not opioid strength and scheduled dosing, was identified as a risk factor for OIC among various covariates assessed in the logistic regression analysis in 81 patients with OIC and Rome IV diagnosis vs 419 patients without OIC in the opioid group. CONCLUSION: Use of opioid analgesics, including weak opioids, for treating chronic non-cancer musculoskeletal pain is associated with OIC. This finding highlights the need for appropriate treatment of constipation in patients with chronic non-cancer pain in Japan. TRIAL REGISTRATION: UMIN000043985. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40122-022-00392-y.