Endocrine Abstracts

Introduction: Over the last five years testosterone therapy in men became more safe, efficient and ‘patient-friendly’ with the introduction of new testosterone preparations. Testosterone gels are in widespread use, but they are associated with the risk of interpersonal transfer and need daily application. Recently, injectable testosterone undecanoate (TU, Nebido^®) has become available in Europe.

Long term data of aging males with long-acting testosterone esters are limited. Specific risk data on the prostate and haematological parameters are not available.

Patients and methods: 33 hypogonadal men with primary, secondary or late-onset hypogonadism between the age 45–79 years (mean: 59.2±7.3 years; x±S.E.) were treated with TU.

29 Patients had been pre-treated, 17 patients with T-gel, 12 patients with intramuscular testosterone enanthate. Two patients assessed tolerability of intramuscular injection as ‘poor’ and dropped out.

21 patients received TU for more than 6 months. Patients were assessed before the first injection and in 6-weekly intervals over the treatment period of 30 weeks. At each consultation, sexual function, mood, quality of life and skin reactions were monitored. Hematology, clinical chemistry, Total Testosterone, SHBG, Dihydrotestosterone (DHT), Estradiol, LH, FSH and prostate specific antigen (PSA) were measured prior the next injection.

Results: Testosterone levels increased from 2.6 ng/ml (±1,09; x±S.E.) [range 2.3–6.00 ng/ml] at baseline to 3.9 ng/ml (±1.35; x±S.E.) after 6 weeks and to 4.73 ng/ml (±1.85; x±S.E.) after 30 weeks of treatment.

DHT levels increased from 286 pg/ml (±141; x±S.E.) [range 310 – 1463 pg/ml] to 905 pg/ml (±299; x±S.E.). PSA levels fluctuated minimally within in the normal range. In two patients the length between two injections could be prolonged from 12 to 14 weeks.

Conclusion: Treatment with TU is a safe and efficacious option for the hypogonadal aging male. Regular clinical and laboratory control is mandatory.