Background: Codeine is an opioid medication widely used for its analgesic, antitussive, and antidiarrhoeal properties. However, increasing concerns have emerged internationally regarding codeine misuse and dependence. Ireland has among the highest levels of over the counter codeine consumption globally, despite relatively low levels of treatment presentations for codeine dependence. This study aims to explore patients who use codeine and general practitioner perspectives on codeine use, dependence, prescribing, and deprescribing within Irish general practice.

Methods: This study will employ a mixed-methods design comprising: (1) secondary analysis of aggregated codeine prescribing data from Irish general practice; (2) a scoping review of clinical guidelines and consensus statements relating to codeine prescribing, detection of iatrogenic dependence, and management of dependence in primary care; (3) an anonymous cross-sectional survey of patients attending general practice in Ireland; (4) semi-structured interviews with patients using OTC codeine and patients prescribed codeine who developed iatrogenic dependence; and (5) focus groups with GPs involved in prescribing codeine and managing codeine dependence. Quantitative data will be analysed in IBM SPSS. Qualitative interview and focus group data will undergo Reflexive Thematic Analysis using NVivo, informed by Braun and Clarke.

Discussion: This study will contribute to regarding codeine dependence in Ireland and inform future prescribing guidance, policy development, patient education, and support pathways within primary care. The findings may also provide insight into the potential implications of future regulatory changes surrounding over the counter codeine availability in Ireland.