Opioid-induced constipation in patients with cancer pain in Japan (OIC-J study): a post hoc subgroup analysis of patients with lung cancer.

OBJECTIVE: To evaluate the opioid-induced constipation burden in the subgroup of patients with lung cancer who participated in the observational Opioid-Induced Constipation in Patients with Cancer Pain in Japan (OIC-J) study. METHODS: The prospective, observational study, OIC-J, included 212 patients with various tumour types, 33% of whom had lung cancer. The incidence of opioid-induced constipation was evaluated using several diagnostic criteria, as well as the physician's diagnosis and patient's subjective assessment. Following initiation of opioids, patients recorded details of bowel movements (i.e. date/time, Bristol Stool Scale form, sensations of incomplete evacuation or anorectal obstruction/blockage and degree of straining) in a diary for 2 weeks. Relationships between patient characteristics and opioid-induced constipation onset and effects of opioid-induced constipation on quality of life were explored. RESULTS: In total, 69 patients were included in this post hoc analysis. The incidence of opioid-induced constipation varied (39.1-59.1%) depending on which diagnostic criteria was used. Diagnostic criteria that included a quality component or a patient's feeling of bowel movement as an evaluation item (i.e. Rome IV, physician's diagnosis, Bowel Function Index, patient's assessment) showed higher incidences of opioid-induced constipation than recording the number of spontaneous bowel movements alone. Opioid-induced constipation occurred rapidly after initiating opioids and had a significant impact on Patient Assessment of Constipation Symptoms total score (P = 0.0031). Patient baseline characteristics did not appear to be predictive of opioid-induced constipation onset. CONCLUSIONS: In patients with lung cancer, opioid-induced constipation can occur quickly after initiating opioids and can negatively impact quality of life. Early management of opioid-induced constipation, with a focus on quality-of-life improvement and patient's assessments of bowel movements, is important for these patients.

Association between opioid usage and rectal dysfunction in constipation: A cross-sectional study of 2754 patients.

BACKGROUND: Opioid use has reached epidemic proportions. In contrast to the known effect of opioids on gut transit, the effect on rectal sensorimotor function has not been comprehensively investigated. METHODS: Cross-sectional (hypothesis-generating) study of anorectal physiology studies in 2754 adult patients referred to a tertiary unit (2004-2016) for investigation of functional constipation (defined by "derived" Rome IV core criteria). Statistical associations between opioid usage, symptoms, and anorectal physiological variables were investigated. Opioids were sub-classified as prescriptions for mild-moderate or moderate-severe pain. KEY RESULTS: A total of 2354 patients (85.5%) were classified as non-opioid users, 162 (5.9%) as opioid users for mild-moderate pain, and 238 (8.6%) for moderate-severe pain. Opioids for moderate-severe pain were associated with increased symptomatic severity (Cleveland Clinic constipation score 18.5 vs 15.1; mean difference 2.9 [95%-CI 2.3-3.6]; P < .001), rectal hyposensitivity (odds ratio 1.74 [95%-CI 1.23-2.46]; P = .002), functional evacuation disorders (odds ratio 1.73 [95%-CI 1.28-2.34]; P < .001), and delayed whole-gut transit (odds ratio 1.68 [95%-CI 1.19-2.37]; P = .003). Differences in anorectal variables between opioid users for mild-moderate pain and non-opioid users were not statistically significant. Hierarchical opioid use (non vs mild-moderate vs moderate-severe) was associated with decreasing proportions of patients with no physiological abnormality on testing (40.2% vs 38.1% vs 29.2%) and increasing proportions with both delayed whole-gut transit and rectal sensorimotor dysfunction (16.6% vs 17.5% vs 28.5%). CONCLUSIONS AND INFERENCES: Opioid use is over-represented in patients referred for investigation of constipation. Opioids for moderate-severe pain are associated with rectal sensorimotor abnormalities. Further studies are required to determine whether this association indicates causation.