Gonadotropin release in infertile men following ketoconazole administration

The pituitary gonadotropin releasing capacity of ketoconazole, (KC, p.o. 800 mg/day for 5 days), GnRH (i.v. 100 micrograms) and clomiphene, (CL, p.o. 100 mg/day for 7 days) was compared in 25 infertile male patients. It was found that KC resulted in a significant increase in serum LH (from 8.94 +/- 1.05 to 17.55 +/- 1.32 U/l), FSH (from 6.68 +/- 1.05 to 9.82 +/- 1.28 U/l), 17-OH-progesterone (from 4.51 +/- 0.34 to 11.35 +/- 0.68 nmol/l) and a decrease in serum testosterone (from 16.62 +/- 1.28 to 11.66 +/- 1.59 nmol/l) and dehydroepiandrosterone (from 6.56 +/- 0.39 to 4.82 +/- 0.37 mumol/l) levels. GnRH was effective in all patients, while CL failed to induce considerable amount of LH release (less than 2 U/l) in 7 patients and ketoconazole in 2 patients. It is important to note that KC was also effective in the CL resistant cases. Furthermore, it has been established that the amount of LH released by KC was midway between that of GnRH and CL. Almost 50 per cent of the patients failed to show a significant FSH release (less than 2 U/l), and in this respect, the three substances were similar. The KC test with its different mode of action can be recommended as a reliable diagnostic method in male patients.