In male hypogonadism find the cause before beginning therapy

I saw yet another patient, a 52-year-old man, who was referred because he had no clinical response to intramuscular testosterone (Depo-testosterone, Pharmacia) 200 mg once a month. Regrettably when he presented with symptoms of male hypogonadism a serum testosterone was ordered and therapy began when the result came back with a low value.

A more complete history and physical examination revealed a very different story, particularly the patient’s perception, dating back seven years, that he was developing breasts. On examination, I could not satisfy myself that breast tissue was indeed present and did not order a mammogram on this first visit. I did check visual fields which were normal and gonadal exam was also normal.

Missing from his initial work up, leaving aside a thorough history and physical, was any attempt to determine whether the hypogonadism was hypothalamic/pituitary or testicular in origin. Often this cannot be determined other than by appropriate lab testing — gonadotrophins luteinizing hormone and follicle stimulating hormone, prolactin, testosterone (total, bioavailable) and sex hormone-binding globulin.

Hypothalamic or pituitary abnormalities warrant an imaging study, preferably MRI with and without contrast with a note to the radiologist explaining what you are looking for.

The treatment of a prolactinoma is not testosterone but bromocriptine or cabergoline.

Low gonadotrophins warrant a search for possible low levels of other pituitary hormones. The first-line treatment here may also not be testosterone, particularly if the patient has not given up on the possibility of having children. I have had some success with the use of clomiphene as first line therapy.

If testosterone therapy is prescribed, transdermal or intra-muscular testosterone preparations are available and the pros and cons of both options need to be discussed in detail with the patient. Optimizing the dose is a function of the patient’s clinical response not the serum testosterone. One thing is clear — one dosing regimen does not fit all. Patients are equally adept at letting you know when the dose is too high or too low.