Review date: 12 August 2020
Citation: Pharmacoepidemiology of testosterone: Impact of reimbursement policy on curbing off-label prescribing. D.J. Handelsman. Pharmacoepidemiology and Drug Safety 2020.
In 2015, criteria for PBS support of testosterone preparations were revised to discourage prescribing for men with non-pathological ‘low testosterone’ (i.e. without pathological hypogonadism). In the absence of evidence for benefit in this group of men, but potential adverse effects on cardiovascular health, the growing use of testosterone posed an unjustifiable economic cost and health risk.
The 2015 PBS changes require prescribing by, or in consultation with, a specialist to qualify for subsidy, regardless of the indication. In addition, the threshold serum testosterone concentration for prescribing to men without established testicular or pituitary disorders was lowered from 8 nmol/l to 6 nmol/l.
To examine the effect of these changes on prescribing behaviour, Prof David Handelsman (Director, ANZAC Research Institute, Sydney, and long-term affiliate of Healthy Male) analysed publicly available PBS data and commercial information about testosterone product sales since 2012.
The changes to the PBS in 2015 have certainly affected PBS testosterone prescribing but overall total testosterone prescribing was not substantially reduced.
The trend in increasing use of testosterone prior to 2015 abated but overall testosterone use has not declined since. What has shifted is the proportion of prescriptions funded by the PBS, from 86% to 66%. This reflects a decrease in PBS-subsidised testosterone prescriptions for ‘low testosterone’, as was the intention of the PBS changes. This appears largely due to reduced PBS support for testosterone prescriptions written by general practitioners. However, it appears that many men who do not fit the revised criteria for PBS subsidy are continuing to use testosterone, bearing the total cost themselves.
Prof Handelsman suggests that continued use of testosterone by men who no longer qualify for PBS subsidy reflects that they have become androgen dependent. In men with a functional hypothalamo-pituitary testicular axis, exogenous testosterone inhibits activity of the axis. If these men cease testosterone treatment, they may suffer transient androgen-deficiency symptoms until normal regulatory function of their reproductive system resumes, which can take several months. Continued use of testosterone to alleviate androgen deficiency symptoms is one way to avoid this withdrawal phase, but it creates a vicious cycle that perpetuates unnecessary use.
The data presented by Prof Handelsman suggest that the men who are continuing to use testosterone without PBS subsidy are those who are middle-aged and likely commenced treatment unnecessarily. ‘Low testosterone’ in these men was likely caused by their poor health, rather than reproductive system pathology.
Avoiding the initiation of testosterone in men who don’t really need it is necessary to curb ineffective and potentially harmful use. ‘Low testosterone’ is not an inevitable consequence of aging. Rather, a fall in testosterone is a consequence of the increasing preponderance of health problems as men age. Maintaining a healthy weight, eating well and exercising are effective ways for men to avoid a decline in their testosterone levels as they age.