From the FDA Drug Label
Monitor serum testosterone, prostate specific antigen (PSA), hemoglobin, hematocrit, liver function tests and lipid concentrations periodically (5.1,5.3,5.9,5.13) The laboratory values that should be monitored, in addition to PSA level, are:
- Hemoglobin
- Hematocrit
- Liver function tests
- Lipid concentrations
- Serum testosterone 1
From the Research
In addition to PSA levels, hematocrit should be monitored in a 6-year-old male with low testosterone starting transdermal testosterone therapy, as it is a crucial parameter to assess the risk of erythrocytosis and its potential consequences on cardiovascular health, as evidenced by a recent study 2. The most recent and highest quality study, published in 2022, found that secondary polycythemia in men receiving testosterone therapy increases the risk of major adverse cardiovascular events and venous thromboembolism in the first year of therapy 2. This study highlights the importance of monitoring hematocrit levels in patients undergoing testosterone therapy. Other important parameters to monitor include:
- Growth velocity
- Height
- Weight
- Tanner staging
- Testosterone levels Regular assessment of these parameters is necessary to maintain therapeutic ranges while avoiding excessive advancement of bone age and minimizing the risk of erythrocytosis and its consequences. It is also worth noting that the current hematocrit cutoff value of 0.54, at which testosterone therapy may be modified, may not be supported by scientific evidence, and other values may be more appropriate in particular patient groups, as suggested by a study published in 2019 3. However, the most recent study on the topic, published in 2022, provides strong evidence for the importance of monitoring hematocrit levels in patients undergoing testosterone therapy, and its findings should be prioritized in clinical practice 2.