About Low Testosterone
Low testosterone, also known as hypogonadism, can be a contributing factor of male infertility. Testosterone is a hormone produced primarily in the testes, and is important to maintaining normal sexual and reproductive function. In men, testosterone plays a key role in the development of male reproductive tissues such as the testes and prostate, as well as helping to maintain:
- Sex drive
- Sperm production
- Bone density
- Muscle strength and mass
- Fat distribution
- Red blood cell production
One cannot take testosterone to improve sperm production. Certain medications (Clomiphene; Arimidix) can be used to help increase one’s own testosterone production. Giving testosterone acts as a male contraceptive, lowering one’s own Testosterone.
Diagnosing Low Testosterone
Diagnosing low testosterone in a patient requires a multi-step process. First, a thorough and validated patient questionnaire e.g. ADAM questionnaire, should be taken to assess symptoms. Symptoms may include low sex drive, erectile dysfunction, changes in mood or energy, depression, and changes in memory and spatial orientation.
Next, a complete physical exam should be performed to assess physical factors, focusing on male sexual development characteristics, the genitalia, as well as a rectal examination. If the patient should have signs and symptoms of low testosterone, a blood test should follow to assess the total testosterone.
Treatment of Low Testosterone
Testosterone Replacement Therapy (TRT), when administered correctly, should improve levels of the hormone without considerable side effects. There are several types of hormone replacement options available including:
- Injectable
- Oral
- Transdermal: Applied to the skin via patch or gel
- Subcutaneous Pellet: Testopel
Injectable Testosterone
There are two forms of injectable testosterone - testosterone cypionate and testosterone enanthate. Injections are required every 2-3 weeks. While injections are a cost-effective method, serum levels are not maintained beyond 2-3 weeks, resulting in high and low level and mood changes. Injectable testosterone also can lead to high incidence of increased red cell mass (elevated hematocrit) and abnormal lipid ratios.
Oral Medications
There are no oral testosterone products currently in use in the US for routine T replacement. Some new oral products are in development.
Transdermal Systems
Transdermal systems are highly effective in restoring testosterone levels to physiologically normal levels.
Patch: Transdermal patches are able to restore testosterone to normal levels. Patches are applied daily and provide a continuous 24 hour release of testosterone. Skin irritation is the most noted disadvantage of the patch. The only available topical patch that is usually prescribed is:
- Androderm: Applied to arm, back, or upper buttocks
Topical Gel: Topical gels are known to cause minimal side effects. They are applied daily to the shoulder, thigh or underarm regions. Patients must be careful to not transfer the gel to other individuals via contact. There are currently five FDA-approved topical gels available:
- Testim
- Androgel
- Androgel 1.67%
- Axilron
- Fortesta
For more information about Testim and how to apply Testim gel, please visit Testim's website.
Subcutaneous Pellet
Testopel is a testosterone pellet that is 1/8 thick in diameter and 1/3 inch in length. They are implanted just underneath the skin in the buttock area every three to four months. This procedure takes about five minutes and can be performed in the office. The pellets are slowly absorbed over three to four months to provide a constant level of testosterone in the blood. This constant absorption of the drug avoids the peak-and-valley effect that injectable testosterones can have. The number of pellets implanted can be titrated up or down depending on the individual patient's testosterone levels and symptoms. Treatment with Testopel pellets has the same risks as all testosterone therapy and requires similar monitoring schedules.
Monitoring of Testosterone Therapy
Patients receiving testosterone replacement therapy should be monitored regularly. Within a month or two of starting therapy, testosterone levels and symptoms should be evaluated. During the first year, the patient should be evaluated regularly to assess response to the testosterone through a more comprehensive evaluation. After the first year, if the patient is stable, they may be evaluated on a semi-annual basis.
Risks of Testosterone Therapy
The risks of testosterone replacement therapy may include:
- Infertility
- Increased prostate symptoms (rare)
- Polycythemia: Excessive red blood count
- Water retention
- Breast tenderness
- Liver damage (only with orals)
- Prostate Cancer: Weak evidence that testosterone therapy cause’s prostate cancer, but may exacerbate existing cancer.
- Worsening of existing breast cancer in men
If a patient is regularly monitored, there should be no irreversible problems secondary to testosterone use.