NEW YORK (Reuters Health) Dec 21 - Clomiphene citrate is a safe and effective treatment for hypogonadism in young men, a new 19-month study shows.

The researchers say this is the longest-term study of clomiphene as a fertility-preserving therapy for men with low testosterone levels , and the largest to look at both objective and subjective responses to treatment.

Dr. John P. Mulhall and colleagues at Memorial Sloan-Kettering Cancer Center in New York City, writing last month in BJU International, note that testosterone -- the standard treatment for hypogonadism -- suppresses secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), leading to testicular atrophy and impaired spermatogenesis.

Clomiphene citrate has been used as an alternative to preserve fertility, but the researchers say there have been few prospective studies of this approach.

Their report focuses on 86 men, average age 29, all with hypogonadism confirmed by two early morning testosterone measurements of less than 300 ng/dL. None of them had been exposed to chemotherapy or pelvic radiation.

Treatment with clomiphene began with 25 mg on alternate days, titrated to 50 mg, with the goal of bringing testosterone levels to between 500 and 600 ng/dL.

During a mean treatment period of 19 months, 70% remained on the 25 mg dose; the rest were on 50 mg. Total testosterone levels went from a mean of 192 ng/dL at baseline to 485 ng/dL, while free testosterone increased from 22 to 95 pg/mL. Estradiol rose from 26 to 39 pg/mL. Both LH and FSH increased significantly as well, from 1.6 to 6.8 IU/mL and from 1.9 to 7.6 IU/mL, respectively.

Based on the androgen deficiency in aging males (ADAM) questionnaire, there were significant improvements in the percentage of men who reported decreased libido (72% to 32%), lack of energy (65% to 40%), decreased life enjoyment (85% to 40%), feeling sad/grumpy (60% to 30%), and decreased sports performance (55% to 25%). Sixty percent of men reported improvement in at least three symptoms, although 10% had no significant improvement in any symptoms.

No serious side effects of clomiphene were observed among the study participants, according to the research team.

The study was not large enough to determine predictors of therapy success or how varicocele status might affect outcome, Dr. Mulhall and his team say. Also, they did not look at how clomiphene affected semen quality.

Nevertheless, they conclude, "Clomiphene citrate therapy has a role to play in the testosterone-deficient man and should be incorporated into the clinician-patient discussion."