Long‐Term Study of Oral Testosterone Undecanoate in Hypogonadal Males

Abstract

Thirty‐four hypogonadal male patients were given testosterone undecanoate (TU) orally for 8 months in a dosage of from 40 to 160 mg/day. Before the start of, and during, the study the patients were interviewed about their libido and their sexual, physical and mental activities, and plasma levels of testosterone (T), 5α‐dihydrotestosterone (DHT), oestradiol (Oe2), FSH, and LH were measured by radioimmunoassays simultaneously. Prostate gland was palpated regularly and a routine laboratory screening programme was also performed.All patients reported a marked increase in libido and sexual, physical and/or mental activities and preferred TU over injectable preparations. Circulating T, DHT and Oe2 rose significantly in all 34 patients and the levels remained stable throughout the whole study. The mean plasma FSH and LH levels in the hypergonadotrophic patients were significantly lowered, but remained above the upper normal limit. In the hypogonadotrophic patients, mean plasma FSH levels increased, but not significantly, while mean LH levels remained unchanged. Neither changes in the size and consistency of the prostate gland, nor abnormal values during the routine laboratory screening programme were observed.