Published: 15 December 2014

Publications

Pump up Testosterone Levels Safely

Prescriber Update 35(4): 52-53
December 2014

Background information on testosterone

Testosterone products are indicated for testosterone replacement in primary and secondary male hypogonadism.

Hypogonadism is defined as a clinical syndrome that comprises both symptoms and biochemical evidence of testosterone deficiency¹.

Testosterone treatments for anti-aging in males and for building muscle are examples of unapproved ('off-label') indications. The safety and efficacy of testosterone when used for unapproved indications are unknown.

In New Zealand, approved testosterone replacement products are available as intramuscular injections, oral capsules and transdermal patches.

Testosterone replacement and risk of cardiovascular events

Recent publications^2,3 have suggested an association between testosterone replacement and an increased risk of cardiovascular events such as myocardial infarction, venous thromboembolism, and stroke.

The Medicines Adverse Reactions Committee (MARC) recently considered the available data on this safety concern. Based on current evidence, the MARC concluded that there is no significant statistical evidence to support an association between testosterone replacement and myocardial infarction, venous thromboembolism, or stroke.

Longer-term, adequately powered, placebo-controlled clinical trials are required to investigate testosterone replacement and the risk of cardiovascular events.

Adverse effects with testosterone replacement

Testosterone replacement used at recommended doses for approved indications has been associated with adverse effects, summarised in Table 1.

Table 1: Potential adverse effects of testosterone replacement [adapted from Bhasin et al]

Adverse effects for which there is evidence of an association	erythrocytosis (leading to polycythaemia) acne detection of subclinical prostate cancer reduced sperm production thereby impairing fertility
Uncommon adverse effects with weak evidence of an association	gynaecomastia male pattern balding (familial) induction or worsening of obstructive sleep apnoea
Adverse effects specific to different dosage forms	Intramuscular injections fluctuation in mood or libido pain at injection site excessive erythrocytosis (especially in older patients) Transdermal patches frequent skin reactions at application site

Further information is available in the product data sheets which are available on the Medsafe website (www.medsafe.govt.nz/Medicines/infoSearch.asp).

References

1. Muraleedharan V, Jones H. 2014. Testosterone and mortality. Clinical Endocrinology 81(4): 477-487.
2. Vigen R, O'Donnell C, Barón AE, et al. 2013. Association of testosterone therapy with mortality, myocardial infarction, and stroke in men with low testosterone levels. JAMA 310(17): 1829-1836.
3. Finkle WD, Greenland S, Ridgeway G, et al. 2014. Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men. PLoS One 9(1): e85805.
4. Bhasin S, Cunningham GR, Hayes FJ, et al. 2010. Testosterone therapy in men with androgen deficiency syndromes: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 95(6): 2536-2559.