Background
Despite no new approved indications for testosterone therapy in recent years (the only unequivocal therapeutic indication is pathological androgen deficiency), there has been a marked increase in testosterone prescribing in Australia (reported by same author in the MJA, 2012) and anecdotal reports of similar increases in other countries.
However, there has been no systematic study of temporal trends in testosterone prescribing around the world.
Aim
To conduct a multinational survey of temporal trends in testosterone prescribing in 41 countries.
Methods
Sales data for all testosterone products were obtained for 41 countries for each year from 2000 to 2011 from IMS Health. Countries were divided into six groups: the Anglosphere (Australia, US, UK, Canada, Ireland), Eastern Europe, Middle Europe, Northern Europe, Southern Europe and Asia.
For each testosterone product type (injectable, implantable, oral, transdermal), the units sold were converted into defined monthly doses per year, as per WHO definition of standard dosing, reflecting total testosterone prescribing per product.
Outcomes measures are national testosterone prescribing rates overall and per product type on a per capita basis.
Results
Total testosterone sales increased 12-fold globally over 11 years – $150 million to $1.8 billion. For every region and 37 of 41 countries, there was a major and progressive increase in defined monthly doses per year per capita over the 11 years.
The most dramatic increase in per capita prescribing was in Canada. Increases were steeper for the second half of the survey period in most countries.
The proportion of testosterone prescribing represented by transdermal testosterone products, a surrogate measure of prescribing for older men, showed a sharper increase than the total usage of testosterone products.
Conclusion
In the absence of any new indications, testosterone prescribing has increased in most countries in 2000–2011, especially over the second half of the time period.
The marked increase seen in Canada is thought to reflect internet pharmacies based in Canada. The increased testosterone prescribing appears to be mainly for older men, given the rise in short-acting transdermal preparations (although age data were not available).
The author argues that the observed trends are likely to be driven by clinical guidelines that endorse testosterone prescribing for age-related functional androgen deficiency (andropause).
By eliminating the fundamental distinction between pathological and functional androgen deficiency, the author suggests these guidelines tacitly promote increased testosterone prescribing despite the lack of high-quality clinical evidence of safety and efficacy.
