(Medical Xpress) -- Testosterone prescriptions have surged since 2006 due to promotional activity, according to University of Sydney research which also found growing overuse in older men.
The research by Professor David Handelsman from the University and director of the ANZAC Research Institute, Concord Hospital has been published today in the Medical Journal of Australia.
It follows another recent study, led by Professor Handelsman and published in the journal of Clinical Endocrinology, which suggests testosterone decline in older men is not a result of ageing but of medical conditions and ill health that accumulate as men get older.
"This Healthy Man Study looked at very healthy men aged 40 and over and found that a decrease in testosterone was not associated with increasing age. Instead factors such as obesity or a history of smoking were strongly linked with any decrease," Professor Handelsman said.
The study supported the interpretation that diseases associated with ageing and not ageing itself affects testosterone levels in older men. It underlines the inappropriateness of the increasing sales of testosterone to older men which is highlighted in Professor Handelsman's MJA article.
The study in the MJA analyses data from the Pharmaceutical Benefits Scheme and IMS, a company that provides national sales data year by year.
"I found that stable market growth over 15 years was disrupted by sharp increases following the introduction of two new testosterone products - a gel and a long-acting injectable version by a single company which became a monopoly supplier," Professor Handelsman said.
"There is growing overuse of testosterone in older men as an anti-ageing tonic and non-specific treatment for sexual dysfunction, for which sound evidence is lacking. Yet at the same time genuine low-testosterone conditions due to diseases of the reproductive system remain underdiagnosed."
At present new uses of testosterone should be restricted to carefully designed clinical trials to determine whether there is any objective benefit from testosterone treatment for conditions such as obesity, diabetes or cardiovascular diseases that accumulate as men age, Professor Handelsman observed.
"The progressive increase appears to be due to promotion-driven marketing of products which do not comply with the Pharmaceutical Benefits Scheme prescribing criteria and suggest that more effective implementation of those criteria is needed."