OFF-label prescribing has fuelled a global surge in testosterone use, according to an Australian researcher who says there are no new clinical indications to explain this increase.
In research published in the MJA, Professor David Handelsman, director of the ANZAC Research Institute, obtained IMS Health sales data of all testosterone products sold in 41 countries and found “a major and progressive increase” in defined monthly doses per year in 37 of these countries. (1)
Professor Handelsman said the findings showed “co-ordinated, global increases in off-label prescribing, apparently mainly for older men, driven by permissive guidelines promoting evidence-free prescribing for functional [androgen deficiency] including andropause”.
While Professor Handelsman conceded the research was limited by a lack of information about the age and prescribing indications, he said the increased proportion of transdermal testosterone products prescribed was a “surrogate measure of prescribing for older men”.
Dr Doug Lording, endocrinologist and andrologist at Melbourne’s Cabrini Hospital, supported the paper’s finding that much of the increased prescribing was likely to be for use in older men for “probably dubious indications”.
“It’s absolutely clear that there’s likely to be a strong element of [non-evidence-based prescribing for older men]”, he said. “Since the transdermal preparations have come on the market, there has been a lot of marketing of testosterone and quite a bit of that marketing has centred around indications which may not be solidly evidence based.”
However, he said some of the increased prescribing rates could be explained by improved education of GPs about the underdiagnosis of true hypogonadism and testosterone deficiency. He said the improvement in availability of reliable testosterone assays had also resulted in improved case-finding of true testosterone deficiency.
Professor Bronwyn Stuckey, endocrinologist and medical director of WA’s Keogh Institute for Medical Research, said evidence for the benefits of testosterone treatment outside of documented androgen deficiency associated with conditions such as Klinefelter syndrome remained scarce.
She said some of the increased testosterone prescribing had been driven by inappropriate prescribing by “well-meaning practitioners” who did not recognise that a patient’s low testosterone levels could be secondary to conditions such as obesity or depression.
“There is a lot of kneejerk prescribing of testosterone, when the problem is not testosterone deficiency, it’s obesity”, Professor Stuckey said. “But that’s not fixed by giving testosterone, that’s fixed by getting men to lose weight.”
There was also “not so well-meaning” prescribing of testosterone by entrepreneurial “andropause” clinics, she said. Testosterone was also often promoted in gyms as a way to increase muscle mass.
“A lot of it is just androgen abuse by gym junkies”, she said.
While the research focused on prescription products, some illicit use was included in the figures.
“Androgens (including testosterone) obtained illicitly via the internet or other non-medical sources are at least partly included, to the extent that virtually all testosterone originates from commercial production facilities that supply wholesalers”, Professor Handelsman wrote.
Dr Lording agreed that the inappropriate use of testosterone by “image conscious” young men was concerning, as was the widespread use of unregulated compounded preparations.
“There is no way of knowing how much androgen is prescribed, but I think the problem is much deeper than this suggests”, he said.
Inappropriate prescribing by medical practitioners of androgens for anti-ageing purposes was also “surprisingly widespread”.
While Dr Lording said care needed to be taken not to throw a “wet blanket” on the prescription of testosterone where clinically indicated, a lack of trial data presented clinicians with a dilemma about when it was appropriate to prescribe testosterone.
Professor Handelsman’s latest research follows on from his 2012 findings that testosterone prescribing was rising in Australia. He said in the MJA article that the increased prescribing rates were likely to be due to “promotion-driven non-compliance with PBS prescribing criteria”. (2)
A spokesperson for the federal Department of Health said the Pharmaceutical Benefits Advisory Committee (PBAC) recently met to consider a drug utilisation subcommittee analysis that had noted a marked increase in testosterone use over the past 5 years. The subcommittee considered that while some use may be attributed to unmet clinical need, a proportion of use might not be within the intended PBS restriction
The spokesperson said the PBAC’s findings would be available in the coming months.