Effects on the endocrine system of long-term treatment with the non-steroidal anti-androgen Casodex in patients with benign prostatic hyperplasia.

OBJECTIVE

To study the hormonal changes resulting from long-term use of the non-steroidal anti-androgen Casodex.

PATIENTS AND METHODS

A randomized, placebo-controlled study was carried out on 27 patients with benign prostatic hyperplasia (BPH). Fourteen patients received Casodex 50 mg daily for 24 weeks and 13 received a placebo. The patients were followed up for a further 24-week period.

RESULTS

Serum concentrations of luteinizing hormone (LH) increased by an average of 40% while follicle-stimulating hormone (FSH) remained unchanged. Testosterone increased by 35%, oestradiol by 29% and oestrone by 23%; all changes were statistically significant. Levels of androstenedione and dihydrotestosterone increased by 11% and 15%, respectively, but these increases did not reach statistical significance. A non-significant increase was also observed for sex hormone-binding globulin. The hormonal changes were reversible upon discontinuation of therapy. Prolactin and dehydroepiandrosterone-sulphate levels did not change.

CONCLUSION

This study indicates that Casodex, due to competitive inhibition of central androgen receptors, increases LH secretion, thus causing increased production and increased metabolism of testosterone.