Article

Testosterone undecanoate maintains spermatogenic suppression induced by cyproterone acetate plus testosterone undecanoate in normal men.

Department of Obstetrics and Gynecology, S Orsola-Malpighi Hospital and University of Bologna, 40138 Bologna, Italy.
Journal of Clinical Endocrinology &amp Metabolism (Impact Factor: 6.43). 01/2004; 88(12):5818-26. DOI: 10.1210/jc.2003-030574
Source: PubMed

ABSTRACT In this study we evaluated whether testosterone undecanoate (TU), alone or combined with low dose cyproterone acetate (CPA), can maintain spermatogenic suppression induced by higher doses of CPA plus TU. Twenty-four men received for 12 wk 20 mg/d CPA plus 1000 mg/6 wk TU and then 1000 mg/8 wk TU plus 20 mg/d CPA (n = 8), 2 mg/d CPA (n = 8), or plus placebo (n = 8) for 32 wk. Blood samples, physical examinations, hormones, chemistry, hematology, semen analysis, and sexual/behavioral assessments were performed throughout the study. Sperm counts decreased to less than 1 million/ml in all subjects by wk 12, and 54% of them achieved azoospermia. Suppression of sperm counts was maintained until wk 44. Serum LH and FSH levels were suppressed by wk 12 of hormone administration and remained suppressed until wk 44. No significant changes in any biochemical parameters were detected at wk 44 in any group. There was a slight increase in total prostate volume to within the normal range at wk 44 that returned to baseline 1 yr after stopping hormone administration. In conclusion, TU alone or combined with lower doses of CPA maintains sperm suppression induced by higher dose CPA plus TU for 32 wk. This prototype regimen represents a promising male contraceptive regimen.

0 Bookmarks
 · 
55 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Research has established the principle of hormonal male contraception based on suppression of gonadotropins and spermatogenesis. All hormonal male contraceptives use testosterone, but only in East Asian men can testosterone alone suppress spermatogenesis to a level compatible with contraceptive protection. In Caucasians, additional agents are required of which progestins are favored. Clinical trials concentrate on testosterone combined with norethisterone, desogestrel, etonogestrel or depot-medroxyprogesterone acetate. The first randomized, placebo-controlled clinical trial performed by the pharmaceutical industry demonstrated the effectiveness of a combination of testosterone undecanoate and etonogestrel in suppressing spermatogenesis in volunteers.
    Contraception 11/2010; 82(5):457-70. · 3.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The potential of using dienogest [DNG, 40 mg/kg body weight (bw)] plus testosterone undecanoate (TU, 25 mg/kg bw) in rats for development of a once-a-month male hormonal contraceptive has been reported earlier in our laboratories. In the present study, we report a separate efficacy evaluation of the same combination, DNG (40 mg/kg bw) and TU (25 mg/kg bw) in which interval of drug administration has been extended further to 45 and 60 days instead of every 30 days. Complete sperm suppression was observed in rats sacrificed either 60 or 90 days after DNG+TU administration, for two injections at 45-day interval. The neutral α-glucosidase activity in these treated rats remained in the normal range. Germ cell loss due to apoptosis was frequently observed both after 60 or 90 days of combination treatment. Significant decline in serum gonadotropin and testosterone, both serum and intratesticular levels, were observed in the treated rats. Following stoppage of treatment (given at 45-day interval) after two (0 and 45 days) or three injections (0, 45 and 90 days), complete restoration of spermatogenesis was observed by 120 and 165 days, respectively. The sperm suppression, however, could not be sustained when the period of combined drug administration was extended from every 45 to 60 days. Dienogest plus testosterone undecanoate in the above doses retained contraceptive effectiveness when administered every 45 days but not 60 days. The spermatogenic arrest was completely reversible once drug treatment is stopped. The dose and the frequency of intervention can be extrapolated in future clinical trials.
    Contraception 06/2011; 85(1):113-21. · 3.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Of all the different experimental approaches and pharmacological methods tested so far for male contraception, hormonal methods come closest to fulfilling the criteria set out above (see Chap. 27). The endocrine feedback mechanism operating between hypothalamus, pituitary and testes is the basis on which hormonal approaches to male contraception rest. Its goal is to suppress spermatogenesis and to reduce sperm concentration, if possible to azoospermia or at least to a sperm concentration low enough to provide contraceptive protection (<1 million sperm per ml ejaculate).
    01/2010: pages 577-587;

Full-text

View
1 Download
Available from