Current prescribing patterns of bupropion in Australia

From the beginning of February to the end of December 2001, 351 772 bupropion prescriptions had been processed by the Health Insurance Commission (HIC) at a cost of $83.14 million.1 This is equivalent to about 2% of total PBS-related drug expenditure in Australia.2 Given this high cost, it is reasonable to consider the extent to which this investment represents value for money.

An important first step is to assess the penetration of bupropion into the population of regular smokers in Australia. One indicator of this is the proportion of regular smokers who have filled a bupropion prescription (Box). Estimates suggest that 22.8% of the population aged 20 years and over (25.2% males and 22.8% females) are current regular smokers.3 Seventy-three per cent (14 099 273) of the Australian population were aged 20 years or over in June 2001.4 Combining population and age-specific smoking prevalence estimates results in an estimated 3 198 738 current regular smokers aged 20 years and over. Given that the PBS guidelines allow for only one prescription of bupropion per smoker per year, an estimated 11% (351 772 prescriptions divided by 3 198 738 smokers) of current regular smokers filled a prescription for bupropion in 2001. Excluding smokers aged less than 20 years will have minimal effect on this estimate, as the incidence of high nicotine dependence in this group is likely to be low.

Applying this method to each State and Territory reveals marked variation between them in the apparent proportions of smokers filling a prescription for bupropion. For example, an estimated 16.5% of all smokers in Tasmania had such a prescription filled, compared with 8% in Victoria. Although data from the HIC may be incomplete,5 the same method is applied to each jurisdiction in compiling them. Key unanswered questions relate to the extent to which (i) smokers complete a full course of bupropion, (ii) the field effectiveness of bupropion in aiding smoking cessation is comparable with abstinence rates achieved in clinical trials, and (iii) bupropion is used in conjunction with a comprehensive treatment program. We are currently conducting research to examine such questions.