Hyperprolactinemia and sexual function in men: a short review

Abstract

Erectile dysfunction (ED), generally associated with reduced sexual desire and sometimes with orgasmic or ejaculatory dysfunction, is the major revealing symptom of hyperprolactinemia (HPRL) in men, a condition that should not be neglected since many cases result from pituitary tumors, likely to result in serious complications. It is generally believed that the mechanism of the prolactin (PRL)-induced sexual dysfunctions is a decrease in testosterone secretion. In fact, serum testosterone is normal in many hyperprolactinemic males and there are also testosteroneindependent mechanisms, probably mainly set at the level of the brain's neurotransmittor systems. Systematic determinations of serum PRL found very low prevalences of marked HPRL (435 ng/ml) in ED patients (0.76% in a compilation of over 3200 patients) as well as of pituitary adenomas (0.4%). In addition, the association of HPRL with ED may have been coincidental in some of these cases, since 10% of the HPRLs diagnosed by the usual immunological assays are composed of macroprolactins, which are biologically inactive or little active variants of PRL. Their identification requires a PRL chromatography that is restricted to some specialized laboratories. There is presently no consensus with regards to the screening for HPRL in ED: systematic determination of serum PRL may be justified since HPRL is a serious but reversible disease, while there is presently no reliable clinical, psychometric or hormonal criteria (including serum testosterone level) allowing to restrict its determination to certain categories of the ED patients without risk of neglecting some HPRLs. In case of consistent HPRL, searching for a hypothalamic or pituitary tumor is mandatory. Dopamine-agonist therapy is the first choice treatment for the PRL-induced sexual dysfunctions. Additional sexual counselling may be necessary for certain patients. Keywords: hyperprolactinemia; erectile dysfunction; inhibited sexual desire; anorgasmia; retarded ejaculation; review Prolactin (PRL) has no known role in physiological control of human sexual behavior, except a possible contribution of the orgasm-induced PRL secretion to the sexual-satiation mechanisms, since sexual satiation has not been observed in a multiorgasmic male. 1 On the contrary, all types of hyperprolactinemia (HPRL) (idiopathic, tumoral or drug-induced) can inhibit most aspects of male sexual behavior. Therefore, although HPRL is a rather rare condition, it may be a cause of male sexual dysfunction, and should not be neglected since it is reversible, and may result from pituitary tumors likely to result in serious endocrine and visual complications due to the tumor's growth. Sexual problems of hyperprolactinemic menA literature review encompassing more than 300 hyperprolactinemic men 2 found sexual dysfunctions in 88%, including erectile dysfunction (ED) almost each time. The most typical pattern associated ED with a reduced sexual desire. Delayed or absent orgasm was associated in some cases, but virtually never isolated. Some cases ...

Testosterone and Erectile Function: From Basic Research to a New Clinical Paradigm for Managing Men with Androgen Insufficiency and Erectile Dysfunction

“…However, if a patient presents with signs and symptoms of diminished sexual interest and gynecomastia, and has biochemical evidence of androgen insufficiency, determination of serum prolactin is recommended [116]. Direct role of prolactin in male libido has been proposed [117]. Although rare, elevated serum prolactin levels are associated with potentially high morbidity disease and pituitary tumors.…”

Preclinical effects of melanocortins in male sexual dysfunction

“…Dopamine lowers prolactin levels and dopaminergic agents are the treatment of choice for prolactinomas. 18 Oxytocin is present in the paraventricular and supraoptic nuclei of the hypothalamus. 19 Central oxytocinergic neurons project to other areas of the brain and the spinal cord, where they are thought to influence memory, learning, sexual behaviors-including penile erection and the postorgasmic feeling of sexual satiety-as well as behaviors such as social attachment and bonding.…”

Specific aspects of erectile dysfunction in endocrinology

“…Hyperprolactinemia is often caused by sulpiride and other antidepressants. 11 If the causative drug is withdrawn, hyperprolactinemia disappears and consequently the resulting clinical manifestations. In the case of primary hyperprolactinemia, the diagnosis is confirmed by elevation of prolactin levels in laboratory tests.…”

“…11 When hyperprolactinemia is caused by a pituitary tumor, it can present as a macroadenoma, because diagnosis is frequently delayed in male patients. Hyperprolactinemia leads to ED at the level of the brain's dopaminergic system and also due to testosterone deficiency secondary to the inhibition of the pulsatile secretion of gonadotropin-releasing hormone (GnRH).…”