- Testosterone treatment may cause blood clots
- Assessing the risk of VTE in testosterone treatment
- Testosterone users have a 63 percent higher risk of VTE
- Testosterone therapy not linked with blood clot disorders in veins, study finds
Testosterone is a sex hormone that’s also available as a prescription medicine to treat male hypogonadism and symptoms of low testosterone levels (low T).
Symptoms of low T may include sexual dysfunction, low energy, and the loss of some male characteristics.
Testosterone works by supplanting the body’s natural production of testosterone.
Testosterone medications come in the form of gels, topical solutions, transdermal patches placed on the skin, buccal patches applied to the upper gums, injections, and pellets implanted under the skin.
The hormone is also used off-label to treat erectile dysfunction (ED) and sexual problems in women.
Both men and women produce testosterone, with levels in men naturally higher.
Low T is often caused by male hypogonadism, when the testes produce little or no sex hormones, including testosterone.
This may result from a problem with the testes themselves (primary hypogonadism) or because of problems in areas of the brain that control hormones, including the hypothalamus and pituitary gland (hypogonadotropic hypogonadism).
The Food and Drug Administration (FDA) originally approved testosterone in 1953.
In 2014, the FDA narrowed the number of conditions that testosterone could be marketed to treat.
Drug makers could label and advertise their hormone products to treat “classic” hypogonadism (primary and hypogonadotropic hypogonadism), but not age-related hypogonadism, because of a concern that low T in old age might be naturally protective.
Testosterone Replacement Therapy
Testosterone levels decline as you age.
Sometimes they decline to abnormal levels, leading to complications such as adrenal fatigue, reduced energy, hypo- or hyperthyroidism, and sexual dysfunction.
Testosterone replacement therapy is designed to restore your testosterone to normal levels. It is administered through injections, patches, or gels.
In 2015, the FDA issued guidance regarding a possible increased risk of stroke and heart attack associated with testosterone replacement. The guidance advises clinicians against the overuse of testosterone therapy.
Talk with your doctor about the possible risks and benefits of testosterone replacement therapy before starting treatment.
Testosterone gels and topical solutions come with a black-box warning about the risks posed to children who are accidentally exposed to the hormone.
Exposure can lead to “virilization,” resulting in:
- Penis or clitoris enlargement
- Pubic hair growth
- Increased erections and libido
- Aging of bones
These products should be applied to body areas not likely to come in contact with children or pregnant women, and the application site should be covered with clothing.
Hands should be washed with soap and water before and after application, and the application site should be washed before any skin-to-skin contact.
If accidental skin-to-skin contact occurs with another person, the affected areas should be washed immediately.
Tell anyone else who contacts things that may have testosterone on them (such as your bed sheets, upholstery, pillows, or clothing) that they need to be careful of exposure.
Testosterone and Prostate Health
You should not use any testosterone product if you have breast cancer, or if you have or may have prostate cancer.
Use of testosterone may increase your risk of prostate cancer and/or worsen the symptoms of enlarged prostate (such as urinary problems), although there has been much debate about this issue recently in the medical literature.
Some researchers believe low doses of testosterone can be safe and effective even in men who have been treated for prostate cancer.
Several small studies have found that men with a history of prostate cancer and at low risk for recurrence have not developed new cancer after treatment with low doses of testosterone therapy.
However, there are many factors that that influence the risks associated with testosterone use.
Tell your doctor about your history of prostate cancer and/or your overall prostate health before starting testosterone therapy.
Testosterone and the Heart
Use of testosterone may cause edema (swelling from the buildup of fluids).
This may lead to congestive heart failure (the inability of your heart to pump enough blood for your body) if you have heart, liver, or kidney disease.
In 2015, the FDA issued guidance advising clinicians against the overuse of testosterone therapy as it has been associated with an increased risk of stroke and heart attack.
Other Testosterone Warnings
Use of testosterone may also:
- Cause sleep apnea, especially if you are very overweight or have chronic lung disease
- Cause gynecomastia (enlarged breast tissue) to develop or persist
- Reduce sperm count
- Cause severe gum irritation (if using the buccal system)
- Cause blood clots in the veins to develop, and arteries in the lungs to become blocked up
- Increase your red blood cell count to dangerous levels (erythrocytosis)
Testosterone topical gel and solution are flammable when wet.
The aluminum present in the transdermal testosterone system may cause skin burns if used during a magnetic resonance imaging (MRI) scan.
Pregnancy and Testosterone
Testosterone should never be used by pregnant women because it can harm developing fetuses.
Though it’s not known how much testosterone is excreted in human milk, breastfeeding women shouldn’t use the drug because of the potential harm it poses to infants. Testosterone is also known to negatively affect lactation.
Women who are pregnant should be especially careful about exposure to men using topical testosterone.
Testosterone for Women
Though testosterone is often considered a male sex hormone, it’s also produced in small amounts by female adrenal glands and ovaries, and it may be linked to women’s sex drive.
The hormone is sometimes prescribed off-label to improve sexual desire in women who no longer have ovaries or have ovaries that aren’t working.
Testosterone is also sometimes prescribed to treat symptoms of menopause.
In one study, reported in the journal Maturitas in 2011, testosterone implants improved symptoms such as hot flashes, sweating, heart discomfort, sleep problems, depressive mood, irritability, anxiety, pain, memory, concentration, and improved sexual desire and satisfaction in postmenopausal women.
Possible side effects of testosterone therapy in women include acne and abnormal hair growth on the face and body.
Testosterone treatment may cause blood clots
The prescription of testosterone replacement therapy has increased dramatically in the last decade, with more and more men aged 40 and older trying to avoid the hormonal effects of aging. However, some researchers warn there may be risks to the treatment. A new study suggests it may increase the risk of serious blood clots.
Share on PinterestTestosterone therapy may increase the risk of venous thromboembolism, study suggests.
To counter the negative effects of aging, many men seek androgen hormone replacement therapy, usually in the form of testosterone.
Testosterone is the hormone that is responsible for masculine growth and development during puberty. Testosterone levels naturally decrease with age.
After the age of 40, many men are diagnosed with hypogonadism, a condition where the body does not produce enough testosterone. As a result, men may experience symptoms similar to that of the female menopause.
Testosterone is commonly prescribed in hypogonadism, as it can improve muscle strength and sex drive. An increasing number of men have been seeking the treatment, with studies showing that the number of testosterone therapy prescriptions in the first decade of this century has nearly tripled.
But there are caveats. In June 2014, the United States Food and Drug Administration (FDA) – in partnership with Health Canada – required that testosterone products carry a warning about the risk of developing blood clots, or venous thromboembolism (VTE).
Assessing the risk of VTE in testosterone treatment
A team of international researchers – led by Carlos Martinez of the Institute for Epidemiology, Statistics and Informatics GmbH in Frankfurt, Germany – decided to investigate the risk of VTE associated with testosterone treatment in men, with a focus particularly on the timing of the risk.
The study – published in The BMJ – collected data from over 2.22 million men registered with the UK Clinical Practice Research Database between January 2001 and May 2013.
Of these, they looked at 19,215 patients with confirmed VTE – including deep venous thrombosis and pulmonary embolism – and 909,530 control participants of the same age.
Researchers identified three main, mutually exclusive exposure groups: current treatment, recent – but not current – treatment, and no treatment in the last 2 years.
Current treatment duration was divided into more or less than 6 months.
Testosterone users have a 63 percent higher risk of VTE
After adjusting for comorbidities and other influencing factors, researchers estimated the rate ratios of VTE in association with current testosterone treatment and compared it with no treatment.
In the first 6 months of testosterone treatment, researchers found a 63 percent increased risk of VTE. This is the equivalent of an additional 10 VTEs above the base rate of 15.8 per 10,000 person years.
This risk decreased significantly after 6 months and after treatment had ceased.
According to the authors, the study highlights the need for further investigation of the temporary increase in the risk of VTE:
“Our study suggests a transient increase in the risk of venous thromboembolism that peaks during the first 3-6 months and declines gradually thereafter. Failure to investigate the timing of venous thromboembolisms in relation to the duration of testosterone use could result in masking of an existing transient association.”
The authors highlight, however, that the risks seem to be temporary and very low in absolute terms.
Martinez and team also note the limitations of their research. Due to the observational nature of their investigation, they cannot draw any conclusions on the cause and effect of this association between VTE risk and testosterone treatment.
Read about a study that suggests testosterone therapy may not increase prostate cancer risk.
Venous thromboembolism is a disease where blood clots form in the veins and cause blockages. The most common forms of VTE are deep vein thrombosis, which occurs often in the legs and pulmonary embolism, which is a clot in the lungs. VTE is the third most common cardiovascular illness, after heart attack and stoke.
“In 2014, the Federal Drug Administration required manufacturers to add a warning about potential risks of VTE to the label of all approved testosterone products,” said Jacques Baillargeon, professor of epidemiology in the department of preventive medicine and community health and lead author of the study. “The warning, however, is based primarily on post-marketing drug surveillance and case reports. To date, there have been no published comparative, large-scale studies examining the association of testosterone therapy and the risk of VTE.”
As a result of this conflicting evidence and the broad media attention it has received, there are many men with medically confirmed low testosterone who are afraid to receive testosterone therapy and there may be physicians who are reluctant to prescribe testosterone therapy based on this conflicting information.
The case-control study included 30,572 men 40 years and older who were enrolled in one of the nation’s largest commercial insurance programs between Jan. 1, 2007 and Dec. 31, 2012. Cases were defined as men who had a primary diagnosis of VTE and received an anticoagulant drug or an intravascular vena cava filter in the 60 days following their diagnoses. Cases were matched with three control subjects on age, geographic region, diagnosis of low testosterone and diagnosis of any underlying pro-clotting condition.
The researchers found that having a prescription for testosterone therapy was not associated with an increased risk of VTE. In addition, none of the specific routes of administration examined — topical creams, transdermal patches or intramuscular injections — were associated with an increased risk. There were no differences between men who received the therapy 15, 30 or 60 days before being diagnosed with VTE.
“It is important to acknowledge, for a man who has medically-diagnosed low testosterone, that there are clear risks to not receiving testosterone therapy, including osteoporosis, sexual dysfunction, increased amounts of fat tissue, decreased lean muscle mass, possible metabolic syndrome and cardiovascular disease,” said Baillargeon. “It’s also important to note that further research needs to be conducted to rigorously assess the long-term risks of testosterone therapy.
These findings may help to inform the benefit-risk assessment for men with testosterone deficiency considering treatment.