From the Guidelines
Testosterone and elevated prolactin levels have an important inverse relationship in men's health, and treating the underlying cause of high prolactin is crucial to restore natural testosterone production. If you have elevated prolactin (hyperprolactinemia), it can significantly lower testosterone levels, causing symptoms like decreased libido, erectile dysfunction, reduced muscle mass, fatigue, and mood changes. According to the most recent and highest quality study 1, medications like cabergoline (starting at 0.25mg twice weekly) are commonly prescribed to lower prolactin levels, as they effectively reduce prolactin production by the pituitary gland.
Key Considerations
- Common causes of elevated prolactin include pituitary tumors (prolactinomas), certain medications (antipsychotics, some antidepressants), hypothyroidism, and chronic stress.
- A complete workup including blood tests, pituitary imaging, and medication review is essential before starting treatment, as recommended by the American Urological Association guideline 1.
- For men with confirmed low testosterone due to hyperprolactinemia, testosterone replacement therapy might be considered, but treating the elevated prolactin is the primary approach since normalizing prolactin often restores natural testosterone production.
Treatment Approach
- Cabergoline is the dopamine agonist of choice, due to its longer half-life and greater affinity for the dopamine receptor, as well as its superior efficacy and safety profile compared to bromocriptine 1.
- Small nocturnal dose increments of cabergoline can effectively diminish the adverse effects of gastrointestinal intolerance and postural hypotension, thereby avoiding trials of less effective dopamine agonists.
- In cases where dopamine agonist resistance or intolerance occurs, neurosurgical intervention or radiotherapy may be considered, as outlined in the consensus guideline for the diagnosis and management of pituitary adenomas in childhood and adolescence 1.
From the Research
Testosterone and Elevated Prolactin
- The relationship between testosterone and elevated prolactin levels is complex, and several studies have investigated the effects of treating hyperprolactinemia on testosterone levels 2, 3, 4, 5, 6.
- Elevated prolactin levels can lead to hypogonadism, which is characterized by low testosterone levels 6.
- Treatment with dopamine agonists, such as cabergoline, can help normalize prolactin levels and improve testosterone levels in men with hyperprolactinemia 2, 5, 6.
- A study found that cabergoline treatment induced prolactin normalization in 84% of male patients with prolactinomas, and testosterone replacement therapy further improved metabolic parameters in hypogonadal patients 6.
- The study also found that testosterone levels were the best predictor of fasting insulin levels, and changes in testosterone levels were significantly correlated with changes in cholesterol, weight, and body mass index 6.
Treatment of Hyperprolactinemia
- Dopamine agonists, such as cabergoline and bromocriptine, are commonly used to treat hyperprolactinemia 2, 3, 4, 5.
- Cabergoline has been shown to be more effective than bromocriptine in reducing prolactin levels and improving symptoms of hyperprolactinemia 2, 5.
- A systematic review and meta-analysis found that dopamine agonists significantly reduced prolactin levels and improved patient-important outcomes, such as tumor growth and visual field defects 5.
- Testosterone replacement therapy may be necessary in hypogonadal men with hyperprolactinemia to improve metabolic parameters and overall health 6.
Metabolic Effects of Treatment
- Treatment with cabergoline and testosterone replacement therapy can improve metabolic parameters, such as body mass index, waist circumference, and lipid profiles, in men with hyperprolactinemia 6.
- The study found that changes in testosterone levels were significantly correlated with changes in metabolic parameters, suggesting that testosterone replacement therapy may have a beneficial effect on metabolism in hypogonadal men with hyperprolactinemia 6.