From the Guidelines
Baseline laboratory tests for testosterone levels should be drawn 2 to 3 months after initiating topical testosterone therapy, and/or after any dose change, to ensure that normal serum testosterone concentrations are being achieved. This recommendation is based on the most recent and highest quality study available, which suggests that testosterone levels should be tested after treatment initiation to determine that normal serum testosterone concentrations are being achieved 1.
Key Considerations
- The timing of testosterone measurements will vary depending on the preparation, but for patients receiving transdermal preparations, levels can be measured at any time, with the understanding that peak values occur 6 to 8 hours after application of the patch 1.
- Testosterone levels should be measured in the morning, between 8 AM and 10 AM, when testosterone levels are naturally at their highest, to provide a more accurate assessment of how the body is responding to the treatment 1.
- The blood draw should occur at the same time of day for all subsequent tests to ensure consistency and accuracy in the results.
Monitoring and Follow-up
- Once stable levels are confirmed on a given dose, monitoring every 6 to 12 months is typically sufficient 1.
- Patients should be monitored to determine that normal serum testosterone concentrations are being achieved, and dose adjustments should be made as needed based on the laboratory results.
Important Notes
- The method of testosterone replacement should be individualized for each patient, and transdermal testosterone preparations are suggested for most hypogonadal men because they usually produce normal serum testosterone concentrations, and patients typically find them the most convenient 1.
- Data regarding the safety of testosterone therapy have been conflicting, and patients should be informed of the possible increased risk of heart attack and stroke with the use of testosterone preparations to treat age-related hypogonadism 1.
From the FDA Drug Label
To ensure proper dosing, the dose should be titrated based on the pre-dose morning serum testosterone concentration from a single blood draw at approximately 14 days and 28 days after starting treatment or following dose adjustment.
Baseline laboratory tests, specifically pre-dose morning serum testosterone concentration, should be drawn at approximately 14 days and 28 days after initiating topical testosterone (T) therapy, and periodically thereafter to ensure proper dosing and to assess the need for dose adjustments 2.
From the Research
Baseline Laboratory Tests for Topical Testosterone Therapy
- The timing of baseline laboratory tests after initiating topical testosterone (T) therapy is crucial for monitoring the effectiveness and safety of the treatment.
- According to a study on monitoring testosterone replacement therapy with transdermal gel 3, serum total T, bioavailable T, and free T levels should be assessed at peak (+2 hours) and minimum (+23 hours) levels after application.
- The study found that serum T levels were significantly lower at +23 hours compared to +2 hours, highlighting the importance of monitoring at both time points to ensure adequate serum T levels throughout the day.
- Another study 4 emphasizes the need to avoid applying testosterone gel at or near the phlebotomy site to prevent spuriously elevated testosterone measurements.
- The optimal timing for drawing baseline laboratory tests after initiating topical testosterone therapy is not explicitly stated in the provided studies, but it can be inferred that tests should be drawn after the treatment has reached a steady state, which may be around 1-3 months after initiation, as seen in studies 5 and 6.
- Factors to consider when drawing baseline laboratory tests include:
- Serum testosterone levels
- Bioavailable testosterone levels
- Free testosterone levels
- Time of application and phlebotomy
- Potential for contamination of blood samples by testosterone gel 4
- By considering these factors and monitoring serum T levels at peak and minimum levels, healthcare professionals can provide a finely tailored treatment for hypogonadal men, preventing supra-physiological levels and maintaining adequate concentrations throughout the day 3.