Testosterone replacement therapy use has increased by 310 per cent in Ontario over 15 years, despite the fact only 6.3 per cent of men newly starting the treatment were actually diagnosed with a condition that would require TRT, a new report concludes.
Researchers at the Institute for Clinical Evaluative Sciences and St. Michael's Hospital in Toronto, who studied TRT rates from 1997, found that one in every 90 men in Ontario 66 years and older is being treated with TRT.
The therapy is meant to be prescribed for men with hypogonadism, a condition in which the body has little or no ability to produce testosterone, said paper author Tara Gomes.
"While the [drugs] may be effective in helping address some of their issues of fatigue and low sex drive, they also might increase their risk of cardiovascular events. So the benefit-harm ratio becomes something important that needs to be discussed," said Ms. Gomes, a scientist at ICES and the Li Ka Shing Knowledge Institute of St. Michael's Hospital.
Health Canada released a warning Tuesday advising consumers and health-care providers "about a potential risk of serious and life-threatening cardiovascular problems linked to testosterone replacement therapy for men."
Researchers speculate that dramatic increase in the use of TRT is linked to the medicalization of the aging process, with the drugs increasingly being marketed for andropause and male sexual dysfunction.
"Marketing increases the patients' awareness of the symptoms," leading them to ask their physicians to prescribe the drug, said Andrew Ching, associate professor of marketing and economics at the Rotman School of Management.
"It's possible what we are seeing is essentially those activities from the marketing perspective outweighed the potential impact of the policy," Ms. Gomes said.
The study, published Wednesday in the journal Plos One, noted that TRT use increased despite the 2006 restriction of public funding criteria for coverage in Ontario (following a 27.9-per-cent temporary decline).
John Aquino, a physician at Ontario Men's Health in Toronto, says the decision to prescribe TRT isn't made lightly.
"We're not about putting our patients on testosterone. We like to make them very aware of the risks. It's not a fun thing to be on," Dr. Aquino said.
There's some discrepancy in the diagnostic process, too, Ms. Gomes concedes.
While tests may indicate some patients have a lower testosterone level, it's not always easy to determine the difference between clinical hypogonadism and the aging process.
"It is a very grey area," Dr. Aquino said. "At the end of the day we take into consideration the symptoms of the patient and what is best for them. It is different for each individual."
Prescriptions for topical formulations, listed on the provincial formulary in 2005, have risen significantly and lead the increase in TRT.
Ms. Gomes said they are considering doing a more "formal review to look at all the evidence around the safety and effectiveness of these products, as well as how they are being used across Canada."