From the Guidelines
Testosterone injections should be stopped when hematocrit levels exceed 54%, as this indicates clinically significant polycythemia. According to the American Urological Association (AUA) guideline 1, a hematocrit (Hct) level above 54% warrants intervention, such as dose reduction or temporary discontinuation of testosterone therapy.
Key Considerations
- Prior to commencing testosterone therapy, baseline measurement of hemoglobin/hematocrit should be performed, and if the Hct exceeds 50%, the etiology should be formally investigated before starting therapy 1.
- While on testosterone therapy, regular monitoring of hematocrit levels is crucial to detect polycythemia early, and intervention should be taken promptly if levels exceed 54% 1.
- Injectable testosterone is associated with the greatest treatment-induced increases in hemoglobin/Hct, making regular monitoring even more critical for patients on this form of therapy 1.
Management of Polycythemia
- If hematocrit levels reach 52-54%, consider reducing the testosterone dose rather than completely stopping therapy to minimize the risk of polycythemia while still benefiting from the treatment.
- When polycythemia is detected, temporarily discontinue testosterone treatment and monitor blood counts every 3-4 months until levels normalize, at which point therapy may be resumed at a lower dose with more frequent monitoring.
- Therapeutic phlebotomy may be necessary to quickly reduce blood viscosity in severe cases of polycythemia.
Preventing Complications
- Patients on testosterone therapy should stay well-hydrated and avoid smoking to minimize additional risk factors for blood clots, as polycythemia can increase the risk of thrombotic events such as stroke or heart attack.
From the Research
Polycythemia and Testosterone Therapy
- The development of polycythemia is a known side effect of testosterone replacement therapy (TRT) 2, 3, 4, 5, 6
- Polycythemia is defined as a hematocrit level of 52% or greater 2, 4
Risk of Major Adverse Cardiovascular Events and Venous Thromboembolism
- Men with polycythemia who are receiving testosterone therapy have a higher risk of major adverse cardiovascular events (MACE) and venous thromboembolic events (VTE) 2
- The risk of MACE and VTE increases when the hematocrit level exceeds 52% 2
Management of Erythrocytosis
- Providers should decrease or discontinue testosterone therapy if the patient's hematocrit exceeds 54% until the hematocrit normalizes 3
- The management of erythrocytosis may include phlebotomy or dose de-escalation of testosterone replacement therapy 4
Hematocrit Threshold for Stopping Testosterone Injections
- There is no specific hematocrit threshold established for stopping testosterone injections, but a level of 54% is recommended as a threshold for decreasing or discontinuing therapy 3
- The decision to stop testosterone injections should be based on individual patient factors and the risk of MACE and VTE 2, 3