Manifestations of hyperprolactinemia may include:
(1) decreased sexual drive
(2) erectile dysfunction
(3) ejaculatory disorder
(4) gynecomastia
Causes of hyperprolactinemia include:
(1) pituitary adenoma
(2) hypothalamic tumor
(3) drug-induced (cimetidine, alpha methyldopa, haloperidol, marijuana, others)
(4) paraneoplastic syndrome
(5) chronic renal failure
(6) idiopathic
Laboratory findings may include:
(1) elevated serum prolactin
(2) decreased serum testosterone (with hypogonadism)
(3) decreased LH and FSH (with hypogonadism)
A mild elevation of serum prolactin is unlikely to be the explanation for male sexual dysfunction.
Some patients with pituitary adenomas will secrete macroprolactin which may be missed by a routine testing for prolactin.
Some patients will experience improved sexual function after treatment or discontinuation of the underlying cause, but some patients will continue to have problems because of comorbid conditions (diabetes, atherosclerosis, smoking, alcohol, etc).