Rates of reported codeine related poisonings and codeine prescribing following the issuance of new national guidance: An Irish Case Study

C. Kennedy1, E. Duggan2, K. Bennett3, D. Williams1. 1Department of Geriatric and Stroke Medicine, Beaumont Hospital, Dublin, IRELAND, 2National Poisons Information Centre, Beaumont Hospital, Dublin, IRELAND, 3Division Population Health Sciences, Royal College of Surgeons in Ireland, Dublin, IRELAND.

Introduction The National Poison’s Information Centre (NPIC) records poisoning case calls including the poison or medication involved. The capture of data by the NPIC has previously shown it to be sensitive to changes in legislation.1 ‘Non-Prescription Medicinal Products Containing Codeine: Guidance for Pharmacists on Safe Supply to Patients’ was published by the Pharmaceutical Society of Ireland in May 2010. The foremost aim was to improve patient safety with regard to possible misuse of products containing codeine by restricting their sale over the counter (OTC). This study aimed to assess the sensitivity of NPIC data to such changes in guidance. It also aimed to identify altered trends of codeine prescriptions due to the reduction in availability of over the counter alternatives.

Method Anonymised enquiry data routinely collected by the NPIC was retrospectively reviewed for a period from 2005 to 2014 inclusive. Cases of codeine poisoning were identified using appropriate database searches and filters. The number of relevant prescriptions for codeine reimbursed by the national health service during the same period were examined. Segmental regression analyses of the interrupted time series studies were used to detect changes in trends (SPSS).

Results 1903 codeine related poisoning were reported to the NPIC over the ten-year period. 2005 saw the highest number of those poisoning (n=199). This reduced to 85 reports in 2014 with a steady decline over the intervening years apart from an increase to 163 in 2010. On analysis, the change in the trend of reports was significant in early 2010 (p<0.05). The majority of cases where reported by doctors and between 50-60% were intentional. There was also an increase in the number of codeine products prescribed from 2010 onwards following analysis of the health service data (p<0.001).

Conclusion Unexpectedly, the number of poisoning involving codeine products rose sharply in early 2010. We surmise that this was due to increased awareness of the dangers with respect to codeine products among healthcare professionals and the public. This may have been the result of an increase in patient counselling at the pharmacy counter and decreased availability in line with national guidance. As these products became less available to the public, the prescribing of codeine containing products increased. This study highlights the effects of national guidance on medication awareness and prescribing.

References 1. Donohue E et al. (2006) Ir J Med Sci 175: 40-42.