“The Most High-Risk People Are Given the Most High-Risk Drugs in the Most High-Risk Way”: Experiences of Treating Problematic Over-the-Counter and Prescription-Only Medication Use in Substance Misuse Services

Misuse of over-the-counter (OTC) and prescription-only medicines (POMs) is increasingly recognised as a public health and medicine-safety concern. Although specialist substance misuse services (SMS) increasingly support people affected by OTC/POM misuse, little is known about how SMS staff perceive the characteristics, challenges, and treatment needs of this population. This study explored the experiences of SMS staff to address this evidence gap and inform pharmacy practice and service development. Confidential semi-structured interviews were conducted with staff across five community adult English SMS. Audio recordings were transcribed verbatim and analysed thematically using NVivo®. Twenty interviews with varied professionals achieved data saturation. Three overarching themes emerged: (1) characteristics of OTC/POM misuse; (2) staff-perceived patterns among people who misuse OTC/POM; and (3) negative experiences and concerns. Dependence on orally administered opioids (particularly codeine-containing products), benzodiazepines and gabapentinoids predominated. Polypharmacy including illicit substance use was also reported. Withdrawal symptoms frequently perpetuated misuse, and abrupt supply cessation created additional risks. Routine enquiry about OTC/POM misuse and provision of tailored harm-reduction interventions are essential. The findings suggest that pharmacists may have an important role in early identification of problematic OTC/POM use, harm-reduction interventions, medicine review and facilitating referral into appropriate treatment pathways. Further research should examine whether dedicated OTC/POM pathways are required and explore differences in demographic and treatment needs across medicine types.