OBJECTIVES: To estimate the prevalence of constipation concomitant to opioid treatment and related resource utilization and costs from the private payer perspective. METHODS: Patients on opioid therapy were identified from a longitudinal insurance claims database consisting in 1,057,033 individuals for a period of 35 months. An algorithm was used to identify patients on opioid therapy with coincident constipation-related claims according to ICD-10 codes, targeted procedures and opioid use criteria. Resource utilization and costs were determined for these individuals and compared with patients on opioid therapy without constipation, without opioid therapy with constipation and without both conditions. Results were compared using ANOVA with a significance level of 0.05 and are presented per individual per month. RESULTS: A total of 23,313 patients were classified as opioid treated patients (2.21% of total population) and 6,678 had events related to constipation (29.03% of the opioid population). Compared with opioid treated patients without constipation, incremental mean total costs per month per patients with the condition were 261.18 BRL (p<0.001). The average cost per month for opioid-related constipation patients was 787.84 BRL, significantly higher than patients on opioid therapy without constipation (526.66 BRL), with no opioid therapy but constipated (284.47 BRL) and without both (90.17 BRL) (p<0.001 for all comparisons). Patients with claims related to both conditions had significantly more days in hospital per month (0.25 vs 0.497, p<0.001), outpatient office visits (1.04 vs. 1.59, p<0.001), outpatient procedures (4.69 vs. 14.05, p<0.001) and tests and therapies (31.95 vs. 36.66, p<0.001) than did patients without opioid-related constipation claims. CONCLUSIONS: The economic burden of patients with constipation events coincident with opioid treatment is significantly higher when compared to all other groups. Constipated patients without opioid therapy had also higher costs than those free of both conditions. These results indicate that reducing opioid-induced constipation has potential cost savings for the health care system.