Prescription Inquiries From Community Pharmacies Regarding Outpatient Opioid Prescriptions: A Retrospective Analysis of Content and Clinical Significance.

Abstract

Opioids are widely used for cancer-related pain but are associated with serious adverse events, making appropriate prescription auditing essential. In Japan, most outpatient opioid prescriptions are dispensed at community pharmacies, where pharmacists play a key role. However, the content and clinical significance of opioid-related prescription audits have not been fully elucidated. To evaluate the content, clinical significance, and impact of prescription inquiries by community pharmacists on outpatient opioid prescriptions. This single-center retrospective cohort study analyzed prescription inquiries related to outpatient opioid prescriptions issued by the National Cancer Center Hospital East between September 2023 and March 2025. Inquiry contents were classified according to drug therapy problems related to efficacy and safety. Pharmacist interventions were evaluated using established rating instruments for medication-order error severity and clinical value. During the study period, 184,688 prescriptions were issued; 10,153 (5.4%) involved inquiries from community pharmacies, including 391 (0.2%) related to opioids, of which 341 (87%) resulted in prescription modifications. Inquiries related to efficacy and safety accounted for 48%, with dosage errors (23%) and treatment duration errors (23%) most common. Overall, 180 cases (46%) were classified as potentially lethal, serious, or significant medication-order errors, and 46% of pharmacist interventions were rated as significant or higher, most frequently involving dosage errors with high severity and clinical value. These findings highlight the critical role of community pharmacists in ensuring safe and appropriate opioid therapy and underscore the importance of collaboration between hospital and community pharmacists in outpatient cancer care.