Long-term substitution therapy of hypogonadal men with transscrotal testosterone over 7-10 years

OBJECTIVE Testosterone (T) substitution of hypogonadal men by conventional intramuscular injection of T esters is not considered optimal because it in duces unphysiologically fluctuating serum T levels. In contrast, scrotal T patches produce normal serum (T) levels mimicking diurnal variations. In or der to assess the quality of this new form of T substitution we followed hy pogonadal men treated by transdermal T up to 10 years. PATIENTS Eleven men aged 35.9 +/- 9.8 years (mean +/- SD) at the beginning of the study were treated with transscrotal T patches (Testoderm(R)) becaus e of primary (n = 4) or secondary (n = 7) hypogonadism, Clinical examinatio ns were performed every 3 months during the first 5 years and every 6 month s thereafter. All 11 patients were seen for 7 years and some for longer per iods: eight for 8 years, six for 9 years and four for 10 years. MEASUREMENTS AND RESULTS With daily application of one patch T levels rose from 5.3 +/- 1.3 nmol/l (mean +/- SE) to 16.7 +/- 26 nmol/l at month 3 and remained in the normal range throughout treatment, Serum 5 alpha-dihydrotes tosterone (DHT) rose from 1.3 +/- 0.4 nmol/l to 3.9 +/- 1.4 nmol/l and oest radiol from 52.3 +/- 9.3 to 71.3 +/- 9.6 pmol/l and remained stable without significant variations throughout the observation period. Patients reporte d absence of local side-effects except for occasional itching. No relevant changes occurred in clinical chemistry, including total cholesterol levels and triglycerides, Haemoglobin and erythrocyte counts remained normal. Bone density measured by QCT increased slightly from 113.6 +/- 5.4 to 129.7 +/- 9.3 mg/cm(3) during the observation period (P=0.028). In the nine patients aged <50 years prostate volumes showed a small but insignificant increase from 16.8+/-1.5 to 18.8 +/- 2.1 mi during transscrotal T therapy. In the tw o older patients prostate volume remained constant or decreased slightly du ring T therapy after an initial increase in the previously untreated patien t. Prostate specific antigen levels were constantly low in all patients. CONCLUSION Transscrotal testosterone patches are well-accepted and safe in long-term testosterone substitution therapy for male hypogonadism.