Purpose: Testosterone replacement therapy via deep intramuscular injections causes extraphysiologic variations in serum testosterone concentrations. A topical transdermal testosterone gel formulation (AndroGel(R)) provides sustained physiologic concentrations of serum testosterone. The objective of this open-label switch study was to compare pharmacokinetics, safety, tolerability, and efficacy of delivery of daily testosterone gel versus intramuscular testosterone injection every 1 or 2 weeks in hypogonadal human immunodeficiency virus (HIV)-infected men.
Method: Patients received intramuscular testosterone (100-200 mg/wk) for 8 weeks, then switched to daily topical testosterone gel (5-10 g gel/day) for 8 weeks. Study endpoints included free serum testosterone concentrations and quality-of-life scores.
Results: Thirty patients (average age, 45 years) were recruited; 24 completed the study. Mean peak free testosterone concentrations with intramuscular testosterone and testosterone gel were 42 pg/mL and 23 pg/mL, respectively, and mean peaktrough fluctuations in free testosterone were 26.7 +/- 12.8 pg/mL and 2.7 +/- 10.7 pg/mL, respectively (p < .001). Quality-of-life scores indicated more improved physical and emotional well-being with gel versus intramuscular testosterone. No significant changes in laboratory parameters or lean body mass were noted.
Conclusion: Daily testosterone gel produced stable testosterone concentrations and improved quality of life compared with intermittent intramuscular testosterone injections.