Testosterone kinetics on hypogonadal men under clomiphene.

OBJECTIVE: To evaluate total testosterone (TT) kinetics and its predictors 6 months after the discontinuation of clomiphene citrate (CC) in patients with hypogonadism. MATERIALS AND METHODS: Consecutive patients with normal testicles and male hypogonadism defined by TT < 300 ng/dl in the presence of signs or symptoms according to the previous consensus were prospectively evaluated in a urologic outpatient clinic by TT levels at baseline (T0), after a daily dose of 50 mg CC for 40 days (T1), and after the washout period of 6 months of CC discontinuation (T2). RESULTS: Among 75 patients, mean age 56.8 years, testosterone at T1 > 300 ng/dl was achieved by 69 (92%), 450-600 ng/dl by 32 (42.6%), and > 600 ng/dl by 27 (36.0%). 18 subjects (24%) maintained asymptomatic and TT levels over 300 ng/dl at T2. Age negatively related to testosterone response and T1 response > 810 ng/dl predicts a median gain of 166.5 ng/dl at 6 months of CC discontinuation. CONCLUSIONS: CC is a compelling option to treat male hypogonadism, although a chronic treatment is needed in most patients. About one in every four patients respond to a CC short trial to "reboot" the physiology. Further understanding of TT kinetics in these patients in the long term is warranted.