The risks of misusing opioid medication have been well documented1,2,3 and include a wide range of problematic consumption outside of medical guidelines. Misuse can include consumption to induce psychoactive effects, use in combination with other drugs to alter their effects, or self-medication by increasing or lengthening duration of dosage without or against medical advice. Such risky behaviour can lead to adverse consequences, including dependence and/or poisoning. Despite the known risks, many countries, including Ireland, continue to permit codeine (an opiate to treat pain) to be available without prescription, over-the-counter (OTC).

In order to address the public health issue of opioid misuse, in 2010 the Pharmaceutical Society of Ireland (PSI) issued guidance in relation to the supply of codeine-containing products. The guidance, Non-prescription medicinal products containing codeine: guidance for pharmacists on safe supply to patients4, provided pharmacists with criteria to be adhered to when selling codeine, such as ensuring that codeine medicines only be supplied when deemed necessary by the pharmacist following consultation and only when a non-opioid analgesic has not proven sufficient to relieve the patient’s symptoms. If codeine is dispensed, the maximum dosage is a three-day supply following which the patient should be medically reviewed.

Methods

In order to measure the impact of these guidelines, a recent study, published in the journal Pharmacoepidemiology and Drug Safety,5 examined two sets of data.

1      The National Poisons Information Centre (NPIC) database was used to assess poisoning rates related to codeine-containing products. NPIC advises healthcare professionals and the public on enquiries relating to poisonings. This database allowed the authors to quantify the reported incidences of codeine-containing products during the period 2005–2016. Using NPIC data, all codeine-related poisonings (non-prescription and prescription) were plotted to measure occurrence pre- and post-2010 (when the guidance was issued).

2      The pharmacy claims database of the Health Service Executive Primary Care Reimbursement Service (HSE PCRS) was used to calculate trends in codeine prescriptions during the same period. This database contains information on all payments made to pharmacists in lieu of products dispensed to primary care patients entitled to reduced cost medicines. For the purposes of the study, all non-prescription co-codamol products (paracetamol and codeine) and two prescription only co-codamol products dispensed by pharmacies under the HSE PCRS scheme were considered. This would identify if there was an increase in those seeking alternative products or prescriptions for codeine-containing products due to the restriction in access to OTC codeine.

Results

Poisonings

Of the 1,851 reported codeine-related poisonings during the period 2005–2016, some 1,346 (73%) were available over the counter. Women made up the majority of case subjects (63%). Paracetamol and codeine was the most frequently reported combination (30%). Intentional poisoning was the most frequently reported event resulting in the poisoning and this remained unchanged when comparing the period 2011–2010.

The majority of referral calls made to NPIC were from hospitals (51%), followed by general practitioner/family doctor (30%), and 16% from the public. Overall, during the period 2005–2016, there was a 53% decrease in reported codeine-related poisonings. Non-prescription (OTC) codeine poisonings decreased by 62% during this period.

In the year following the introduction of the guidelines (2011), a significant decrease (33%) was evident in poisonings involving non-prescription (OTC) codeine, after which there was little change in the rate of poisonings.

Prescriptions

Using a similar timeline (2006–2015), analysis of the HSE PCRS data showed no significant change in the number of reimbursements for prescription codeine-containing products or alternative OTC opioid medications when comparing before and after the introduction of the guidance.

Conclusion

The new guidance on codeine supply coincided with an initial reduction in reported codeine poisoning cases, particularly OTC cases, and this may have been related to the restriction of same. However, the overall reduction was in keeping with previous trends, although of a larger magnitude. The rate of decline did not continue and has plateaued. There was no concurrent increase in the prevailing rate of prescription claims for these products or potential substitutes.

The data highlight the impact of the guidelines and show that they are effective but only for a limited period of time, and, as such, further restrictions on codeine-related products may be required to improve public health outcomes. 

2  Dalton P, Kennedy J and Weedle P (2009) Use and abuse of over-the-counter (OTC) medicines containing codeine in Ireland [Abstract]. Drug Utilisation Research Group (UK & Ireland) Conference 2009, London. Pharmacoepidemiol Drug Saf, 18(6): 523.

3  Foley M, Carney T, Rich E, Parry C, Van Hout MC and Deluca P (2016) Medical professionals’ perspectives on prescribed and over-the-counter medicines containing codeine: a cross-sectional study. BMJ Open, 6(7): e011725. https://www.drugsandalcohol.ie/25819/

4  Pharmaceutical Society of Ireland (PSI) (2010) Non-prescription medicinal products containing codeine: guidance for pharmacists on safe supply to patients. Version 1. Dublin: PSI. https://www.drugsandalcohol.ie/13191/ [Version 4 is also available]

5  Kennedy C, Duggan E, Bennett K and Williams DJ (2019) Rates of reported codeine-related poisonings and codeine prescribing following new national guidance in Ireland. Pharmacoepidemiol Drug Saf, 28(1): 106–111. https://www.drugsandalcohol.ie/30150/