The up-scheduling of codeine to a Prescription Only Medicine (Schedule 4) in February 2018 has resulted in a significant decrease in the amount of codeine supplied to Australian patients.
The decision to up-schedule codeine products to prescription only was taken after evidence showed that medicines containing low-dose codeine combined with paracetamol or nonsteroidal anti-inflammatory drugs (NSAIDs) - such as ibuprofen or aspirin - were generally no more effective than other non-codeine medicines. The codeine-containing combinations were also associated with a number of health risks including addiction leading to misuse, liver damage, gastrointestinal perforations, blood potassium imbalances and respiratory depression. These risks were judged to be too high for the codeine combination products to be supplied without oversight from a doctor.
A Therapeutic Goods Administration (TGA) analysis of pharmaceutical industry sales data provided by IQVIA - a company specialising in collating and analysing data sets in the health sector - showed that the total number of codeine-containing products supplied in Australia during 2018 was approximately 50 per cent lower than the average total supplied in the previous four years (17.1 million packs in 2018 compared to an average of 34.7 million per year from 2014-2017). The 2018 total included one month of sales data (January 2018) before the up-scheduling came into force, and so still includes some data for sales of over-the counter codeine-containing products.
For the first 11 months after up-scheduling, more than 15.3 million packs of codeine-containing products were supplied in Australia, totalling 8254 kg of codeine. A projection of the quantities of codeine that would have been sold if there had been no up-scheduling and past supply trends had continued arrived at a figure of 15,213 kg. The actual amount supplied was 46 per cent less than this - indicating that up-scheduling had resulted in a decrease of 6959 kg of codeine supplied to patients.
The TGA also looked in detail at the supply of high-strength (30 mg codeine) Schedule 4 codeine-containing medicines. Our analysis does not support the assertion that many patients were switched from low- to high-strength codeine medicines after up-scheduling. Between February and December 2018, the supply of high-strength 30 mg Schedule 4 codeine was 7274 kg, as compared with the projected 6816 kg without up-scheduling. The difference was not statistically significant.
The above supply estimates were based on a trend analysis of monthly per capita data between 2014 and 2018, using the IQVIA sales and ABS population data. The analysis was conducted for all codeine products combined, as well as separately for long-standing Schedule 4 and 8 high-strength (30 mg) codeine-containing products, and for the lower-strength codeine products that were up-scheduled. The analysis excluded the data between November 2016 and January 2018 because of considerable fluctuations in codeine product sales data that surrounded the public consultation and announcement of the up-scheduling.
Our modelling showed that the decreases in total codeine sales were not due to long-term trends in the monthly per capita supply, which we found to be stable.
The IQVIA data are aggregates and so do not allow us to draw conclusions about codeine usage among population subgroups (for example by age and sex) or trace individual patients' medicine supply over time.
We are currently undertaking further analyses of the IQVIA data and will also include comparisons with other data sets (for example, Pharmaceutical Benefits Scheme data) to further understand the impact of up-scheduling on the amounts of codeine dispensed. The TGA will publish the results of these analyses as they are completed.
