From the Guidelines
Increased prolactin, or hyperprolactinemia, requires immediate evaluation to determine its cause and appropriate treatment to prevent long-term morbidity and mortality, as well as to improve quality of life. The most recent and highest quality study, published in 2024 in Nature Reviews Endocrinology 1, highlights the importance of evaluating hyperprolactinemia in the context of various underlying conditions, including pituitary tumors, hypothyroidism, and medication-induced causes.
Causes of Hyperprolactinemia
Common causes of hyperprolactinemia include:
- Medications, especially antipsychotics, metoclopramide, and some antidepressants
- Pituitary tumors (prolactinomas)
- Hypothyroidism
- Pregnancy
- Breast stimulation
- Chronic kidney disease
- Severe liver disease
- Intracranial hypotension
- Tetrahydrobiopterin deficiencies
Diagnosis and Management
According to the consensus guideline for the diagnosis and management of pituitary adenomas in childhood and adolescence: part 2, specific diseases 1, baseline macroprolactin levels should be assessed where serum prolactin is found to be mildly or incidentally elevated. Additionally, a single prolactin measurement taken at any time of the day is sufficient to assess hyperprolactinaemia 1.
Treatment
For prolactinomas, dopamine agonists like cabergoline or bromocriptine are the first-line treatments, which work by mimicking dopamine to inhibit prolactin secretion 1. Treatment typically continues until prolactin levels normalize and tumor shrinkage occurs. Regular prolactin level monitoring and pituitary MRIs are necessary during treatment to assess response.
Monitoring and Follow-up
Symptoms that warrant treatment include irregular periods or amenorrhea, infertility, decreased libido, erectile dysfunction, galactorrhea, and osteoporosis risk. For mild, asymptomatic hyperprolactinemia without an identifiable tumor, monitoring may be sufficient. However, regular follow-up and reassessment are crucial to prevent long-term complications and to improve quality of life.
Side Effects and Considerations
Side effects of dopamine agonists include nausea, dizziness, and headache, which often improve with continued use or dose adjustments. It is essential to weigh the benefits and risks of treatment and to individualize management plans based on patient-specific factors and underlying conditions.
From the Research
Causes of Increased Prolactin
- Hyperprolactinemia can be caused by various factors, including physiologic, pharmacologic, and pathologic conditions 2
- Prolactin-secreting pituitary adenoma (prolactinoma) is a common cause of hyperprolactinemia, especially if serum prolactin levels are above 200 microg/L 3
- Other causes of hyperprolactinemia include intake of certain drugs, compression of the pituitary stalk, hypothyroidism, renal failure, cirrhosis, chest wall lesions, or idiopathic hyperprolactinemia 3
Symptoms of Increased Prolactin
- Hyperprolactinemia can cause hypogonadism, leading to symptoms such as amenorrhea/oligomenorrhea, anovulation, and galactorrhea in women, and diminished libido and erectile dysfunction in men 4
- Macroprolactinomas can also cause symptoms and signs resulting from mass effect of the tumor, such as headaches and visual field defects 4
Treatment of Increased Prolactin
- The primary treatment of prolactinomas is pharmacological with dopamine agonists such as cabergoline 4
- Cabergoline is a long-acting dopamine agonist that is effective in reducing prolactin levels and restoring gonadal function 3, 2, 5
- Cabergoline has a favorable profile compared to other dopamine agonists, with a longer duration of action and better tolerability 3, 2, 5
- Surgical resection of the prolactinoma is an option for patients who do not respond to pharmacological therapy or who refuse long-term treatment 3