A clinical trial of injectable testosterone undecanoate as a potential male contraceptive in normal Chinese men

• Published in: The journal of clinical endocrinology and metabolism 1999-10, Vol.84 (10), p.3642-3647
• Main Authors: ZHANG, G.-Y, GU, Y.-Q, WANG, X.-H, CUI, Y.-G, BREMNER, W. J
• Format: Article
• Language: English
• Subjects: Adult; Asian Continental Ancestry Group; Biological and medical sciences; Body Weight - drug effects; Contraceptive Agents, Male - administration & dosage; Contraceptive Agents, Male - adverse effects; Contraceptive Agents, Male - pharmacology; Dose-Response Relationship, Drug; Double-Blind Method; Endocrinopathies; Gonadal Steroid Hormones - blood; Hemoglobins - analysis; Humans; Hypothalamus. Hypophysis. Epiphysis (diseases); Injections; Lipids - blood; Male; Medical sciences; Middle Aged; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Organ Size - drug effects; Pilot Projects; Reference Values; Sperm Count - drug effects; Testis - anatomy & histology; Testosterone - administration & dosage; Testosterone - adverse effects; Testosterone - analogs & derivatives; Testosterone - pharmacology; Tropical medicine
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.84.10.3642

This is a pilot dose-finding study of spermatogenic suppression using testosterone undecanoate (TU) injections alone in normal Chinese men. Thirty-two healthy men were recruited. Volunteers underwent pretreatment evaluation, then a treatment period in which group I (n = 13) received 500 mg TU, group II (n = 12) received 1000 mg TU, and group III (n = 7) received placebo, respectively, at monthly intervals during the treatment period (or until azoospermia was achieved). Thereafter, they underwent a recovery period until all parameters returned to pretreatment levels. Eleven of 12 volunteers in the 500-mg TU group, and all volunteers in the 1000-mg TU group became azoospermic. Faster suppression of spermatogenesis was achieved in the 1000-mg TU group. Serum testosterone increased significantly in the higher dose group at weeks 8 and 12, but remained within the normal range. Mean serum LH and FSH were profoundly suppressed by both doses to undetectable levels at week 16. TU injections did not cause a significant change in high density lipoprotein cholesterol levels. No serious side-effects were found. We conclude that both dosages of TU can effectively, safely, and reversibly suppress spermatogenesis in normal Chinese men.