Background: The release of the results of the oestrogen plus progesterone therapy (EPT) arm of the Women's Health Initiative (WHI) in July 2002 started a worldwide process of reconsideration of the rationale behind hormone therapy (HT). This process was accelerated after the release of the results from the oestrogen-only (ET) arm of the same study. The results of the WHI reinforced the indications of HT to alleviate vasomotor symptoms and to prevent bone loss associated with early menopause, but refuted the possibility of cardioprotective effects and raised uncertainty around the risk of breast cancer for long-term users. In response, new guidelines and position statements were developed to aid healthcare practitioners and patients in various countries, including South Africa. The dissemination and penetration of all this information has been assessed in a number of countries, but the extent of its effect on the South African market is as yet unknown. Accordingly, the aim of this study was to assess the use of HT in the South African private sector from 2001 to 2005.

Methods: Monthly HT sales data for January 2001 to October 2005 were obtained from IMS Health (SA). Three successive periods were compared: (1) January 2001 to June 2002 (discontinuation of the WHI oestrogen plus progestogen arm), (2) July 2002 to February 2004 (termination of the WHI oestrogen only arm) and (3) March 2004 to October 2005.

Results: Overall, sales of HT fell 6.9% between periods 1 and 2 and 14.6% between periods 2 and 3. The total sales of ET predominated; they were more than double those of EPT. For ET, the sale of conjugated equine oestrogen (CEE) preparations exceeded those of non-CEE ET preparations, while for EPT preparations the reverse was true. The decline in ET sales was mostly accounted for by the fall in sales of CEE, by 9.8% and 20.6% for the two periods respectively. There was an increase in sales of both low-dose CEE and non-CEE, although the magnitude of increase in the case of the latter was much greater. Throughout the entire study period, CEE 0.625 mg tablets were found to account for the greatest sales volumes. Private sector sales represented 74.4% of total national HT sales over this period.

Conclusion: The release of the WHI findings resulted in a modest decrease in HT sales in South Africa, although it was less dramatic than sales reported elsewhere. The change in prescribing cannot be attributed to any single factor. Factors such as publicity, adherence to new guidelines, and pharmaceutical marketing may all have contributed. Guidelines need to be updated as the results of new research continue to be published. There is also a need to periodically review prescribing trends, and to assess compliance with evidence-based guidelines, in order to improve the quality of medicines use. The majority of prescriptions for HT in South Africa are written by general practitioners, rather than by specialists. It is thus imperative that guidelines be appropriately framed for this market, as well as interpreted and applied.