Monitoring Serum Testosterone Levels on Androgen Therapy with Long-Acting Testosterone Esters in the Prepubertal and Pubertal Age Groups

Long-acting intramuscular testosterone esters at various doses using various protocols are suggested for the treatment of micropenis and/or delayed puberty of childhood. The objective of this study was to determine the duration of effective testosterone concentration and the optimum interval for the injections. Twenty cases were included in the study. Ten cases were in the prepubertal age with micropenis and the remaining 10 cases were in the pubertal age with constitutional delay of puberty. The prepubertal and pubertal group respectively received 50 mg or 100 mg of long-acting testosterone esters (sustanon) intramuscularly once a month. Blood samples for plasma testosterone levels were taken at the onset and on the 7th, 15th and 30th days of treatment. In the prepubertal group the mean 7th, 15th and 30th day plasma testosterone levels were found to be significantly higher than the mean level before treatment. In the pubertal age group, the desired effective plasma testosterone level was reached on the 7th day but we observed that the level decreased significantly on the 15th day and that the effect vanished on the 30th day. Intramuscular treatment with sustanon 100 mg once a month could not sustain an effective level on the 15th day in 85.7 % of the pubertal age group. Intramuscular treatment with sustanon 50 mg once a month is sufficient to improve penile length but causes a marked increase in the serum testosterone levels on the 7th day of treatment and sustanon 25 mg once a month may therefore be preferred in the prepubertal group. In the pubertal age we conclude that intramuscular sustanon 100 mg treatment should be given every 15 days.