Treatment of anorchia with oral testosterone undecanoate: pharmacodynamics and clinical effectiveness.

The pharmacodynamics of plasma testosterone (T) and androstenedione (A) levels were studied in ten hypogonadal boys after oral administration of testosterone undecanoate (TU). Plasma T and A levels were measured by specific radioimmunoassays. Six hours after a single dose of 120 mg TU, there was a significant increase (P < 0.005) in plasma T and A with a median T peak level of 940 ng/100 ml. Furthermore, twelve agonadal boys treated with a mean dose of 60 mg TU/day were examined over a period of 18-24 months. During this therapy, plasma T and A levels were significantly higher than before (P < 0.005), whereas plasma levels of LH and FSH did not decrease significantly. With the exception of one anorchic boy, all patients showed signs of sexual maturation, such as growth of pubic and axillary hair, and steady development of bone age during oral TU treatment.