Our study evaluated the compliance rate of opioid use, storage, and disposal and the impact of providing information has on the compliance rate, from the perspective of families of deceased cancer patients. In this study, a small number of participants indicated diversion had occurred.
The most important finding from this study was that the compliance rate of opioid use and storage was high, as compared to accurate disposal in bereaved families. In our study, the percentage of unsafe use, secure storage, and disposal to a pharmacy or medical provider were 0.4%, 73.8%, and 59.2%, respectively, compared with 26.0%, 78.0%, and 8.0% in a previous study of cancer patients from the US. It must be noted here that opioids are not recommended routinely to be returned back to the prescriber or pharmacy in the US. The high compliance rate in our study might be influenced by an unrealistic fear of addiction and life-shortening behaviors prevalent in Japan (12)(13). However, our study highlighted that the diversion of opioids by bereaved family members also occurs in Japan. Before the last decade, about 40% of terminally ill cancer patients had a fear of addiction in the US (14). However, opioid prescriptions for chronic pain have dramatically increased in the US (1, 2), thereby increasing access to opioids. These changes in opioid consumption might reflect the differences between the present study and previous studies concerning the compliance of opioid use, storage, and disposal. Japanese families demonstrated the high compliance rate of opioids use, storage, and disposal. However, a small number of participants indicated diversion occurred. Therefore, future challenges include maintaining a high compliance rate and preventing the diversion of opioids to an illegal marketplace.
Secondly, we found that providing information about disposal and prohibition of diversion of opioids increased the compliance rate of correct opioid management by family members of deceased cancer patients. Education for patients and their families plays an important role in preventing opioid-related problems, such as abuse, misuse, and dependency (5, 15). In a group of patients who were prescribed opioids for non-cancer pain, a web-based education program concerning opioid storage and disposal increased patient knowledge about appropriate use, secure storage, and disposal (16). In cancer patients, the provision of educational materials (EM) improved patient-reported safe use (18% with EM vs. 25% without EM), storage (75% with EM vs. 70% without EM), and disposal (76% with EM vs. 28% without EM) of opioids (9). Additionally, providing information about opioid disposal increased the number of patients returning unused opioids to a pharmacy (55.6% with information vs. 17.2% without information) (17). From these studies, it is evident that patients who received information demonstrated safe use, secure storage, and adequately disposed of prescribed opioids. In this study, information was provided by pharmacists for nearly 40% of participants. The ASHP guidelines recommend that family education regarding the safe and legal disposal of medication should extend beyond the patient’s death, to prevent diversion and illegal disposal and, consequently, have a greater impact on family and public health (10). A Japanese nationwide survey of 500 pharmacies found that 76.3% of pharmacies had engaged in the disposal of unnecessary medicines and used medical equipment (18). Additionally, our previous study at a palliative care clinic indicated that pharmacists discovered patient related problems with opioid disposal and subsequently educated on adequate disposal (19). Although a system-based approach for the opioid epidemic is necessary in the US (5, 20), education and provision of information by pharmacists and pharmacies may be an appropriate strategy in preventing an opioid epidemic in Japan.
In the future, if opioids are commonly prescribed for non-cancer pain, diversion, unsafe storage, and illegal disposal of opioids might also occur in Japan. The pharmacy- and pharmacist-based approach for providing information along with physician/provider led education programs about safe use, secure storage, and adequate disposal of opioids for both patients and families has the potential to maintain high compliance rates. Further studies investigating the necessary content and delivery of education programs are needed.
Our study had several limitations. First, we could not rule out recall bias in the questionnaire. There is a possibility that the participants were reluctant to answer honestly about the use of opioids. Second, the questionnaire had a moderate response rate and there were many missing data values. Third, our study did not investigate the role of risk factors for the misuse and abuse of opioids such as alcohol, smoking, and history of substance abuse. When prescribing opioids, it is recommended that patient risk factors are identified, and these patients should be monitored (21). Further studies evaluating the influence of risk factors on compliance are required.