Nadia Barozzi

Cross national drug utilization studies can provide information about different influences on physician prescribing. This is important for medicines with issues around safety and quality of use, like non selective non-steroidal anti-inflammatory drugs (ns-NSAIDs) and cyclo-oxygenase-2 (COX-2) inhibitors. To enable comparison of prescription medicine use across different jurisdictions with a range of population sizes, data first need to be compared within Australia to understand whether use in a smaller sub-population may be considered as representative of the total use within Australia. The aim of this study was to compare the utilization of non selective NSAID, COX-2 inhibitors and paracetamol between Queensland and Australia.

Objectives: To analyse how the prescribing of cyclooxygenase‐2 (COX‐2) inhibitors, non‐selective non‐steroidal anti‐inflammatory drugs (ns‐NSAIDs) and paracetamol (acetaminophen) changed when rofecoxib was withdrawn in 2004.Method: COX‐2 inhibitors, paracetamol and ns‐NSAID's use was measured using dispensing data for concession beneficiaries subsidized by the Australian Pharmaceutical Benefit Scheme (PBS) for the period of 1997–2005. Data were downloaded from the Medicare Australia website and converted, according to the World Health Organization (WHO) Anatomical Therapeutic Chemical (ATC)/Defined Daily Dose (DDD) (2005), to DDD/1000 concession beneficiaries/day.Results: In the period 2000–2004, the use of COX‐2 inhibitors was progressively increased. Overall NSAID's use changed from approximately 80 to 105 DDD/1000 concession beneficiaries/day while a decrease of ns‐NSAIDs from about 70 to 40 DDD/1000 concession beneficiaries/day was observed. Following rofecoxib withdrawal, the overall NSAIDs use declined. In 2005, celecoxib prescription declined (23%) while prescription of meloxicam increased by 62%. Use of paracetamol was steady over the period 1997–2004 (around 40 DDD/1000 concession beneficiaries/day). In April 2005, a slight increase in paracetamol use was observed.Conclusion: Our analysis showed that COX‐2 inhibitors prescribing markedly influenced the overall NSAIDs prescribing in Australia. When COX‐2 inhibitors were introduced their uptake was rapid and extensive. Following rofecoxib withdrawal, the total overall dispensing of NSAIDs returned to a similar value as before COX‐2 inhibitors' introduction. The decrease was due both to rofecoxib withdrawal and to a reduction in celecoxib prescribing. However, meloxicam use increased. Paracetamol prescribing was steady, between 1997 and 2005 and was not affected when the COX‐2 inhibitors were introduced on to the market and after rofecoxib withdrawal, rather than increasing as might have been anticipated after rofecoxib withdrawal. Copyright © 2007 John Wiley & Sons, Ltd.