BackgroundPatients' potential misconceptions and concerns about using opioids are among the primary causes of patient-related barriers that may lead to failure in pain management. These barriers can be eliminated through educational interventions, thus achieving better pain management.ObjectiveThe aim of this study was to assess patients' beliefs about opioids, reduce the impact of patient-related barriers through educational intervention by a clinical pharmacist, and improve patients' adherence to opioid analgesic treatment.SettingThe study was conducted in the Hacettepe University Training and Research Oncology Hospital, Department of Algology in Ankara, Turkey.MethodA prospective study conducted between September, 2018 and May, 2019. Patients were included who had been diagnosed with cancer, had been prescribed opioid analgesics, and who attended the pain unit during the period this study was conducted. Patients' beliefs about opioids were assessed using the Beliefs about Medicine Questionnaire (BMQ) right before and 1 month after an educational intervention was provided by a clinical pharmacist. Also, patients' adherence to the opioid regimen was assessed using a validated Self-Report Measure of Adherence questions in Turkish.Main outcome measureThe mean scores of the BMQ Necessity Subscale and Concern Subscale, and a level of adherence to opioid treatment.ResultsSixty patients who met the inclusion criteria were included and follow-up was completed with 38 patients. Although an increase was detected in the total score of the Necessity subscale after provision of education (p = 0.398), a statistically significant (p < 0.001) decrease was found in the total score of the 'Concern' subscale, which suggests that patients believe the benefits of opioids outweigh the risks. The patients' pain scores were decreased (p = 0.004); furthermore a significant increase was found in the adherence scores (3.16-3.55) (p = 0.027), and a high level of adherence was observed among the patients in the post-education assessment (p = 0.021).ConclusionThe integration of a clinical pharmacist into the pain management team may have a positive impact on the patients' knowledge, concerns and misconceptions about opioids, which may improve adherence and effective pain management in cancer treatment.