Absolute bioavailability of testosterone after oral administration of testosterone-undecanoate and testosterone
The plasma levels of testosterone (T) were measured after oral administration of 25 mg T and 40 mg testosterone-undecanoate (TU) in a group of young women by a specific radioimmunoassay. Plasma levels were compared to those after intravenous administration of 1.5 ug testosterone/kg to another group of young women for determination of absolute bioavailability. Due to the high metabolic clearance rate of 24.5 ml/min/kg absolute systemic availability of free testosterone was calculated to 3.56±2.45%. Oral administration of testosterone undecanoate leads only to an absolute testosterone bioavailability of 6.8±3.32%.
Key-wordsTestosterone testosterone-undecanoate absolute bioavailability oral administration
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