From the Guidelines
The workup for hyperprolactinemia begins with confirming elevated prolactin levels through repeat testing and excluding physiologic causes like stress, sleep disruption, exercise, and pregnancy, as recommended by recent guidelines 1.
Initial Evaluation
The initial evaluation should include laboratory tests to rule out other causes of hyperprolactinemia, such as:
- Thyroid function tests
- Renal and liver function tests
- Assessment for medications that can elevate prolactin (antipsychotics, metoclopramide, verapamil, estrogens)
Imaging Studies
Magnetic resonance imaging (MRI) of the pituitary is indicated to evaluate for prolactinomas or other sellar masses, especially in cases with high prolactin levels or symptoms suggestive of a pituitary tumor.
Management
Management depends on the underlying cause and clinical presentation.
- For microprolactinomas (<10mm) in asymptomatic patients without desire for fertility, observation may be appropriate.
- First-line pharmacotherapy involves dopamine agonists, with cabergoline preferred over bromocriptine due to better efficacy and tolerability 1.
- Treatment goals include normalizing prolactin levels, reducing tumor size, and resolving symptoms such as galactorrhea, menstrual irregularities, and sexual dysfunction.
Monitoring and Follow-up
Regular monitoring includes prolactin levels every 1-3 months initially, then every 6-12 months, with follow-up MRIs at 3-6 months after treatment initiation and then annually until stable.
Special Considerations
- In cases with large pituitary lesions and normal or mildly elevated prolactin levels, serial dilutions of serum for prolactin measurement should be performed to rule out the "high-dose hook effect" 1.
- Assessment for macroprolactin levels should be considered in cases with mildly or incidentally elevated prolactin levels 1.
From the FDA Drug Label
Since hyperprolactinemia with amenorrhea/galactorrhea and infertility has been found in patients with pituitary tumors, a complete evaluation of the pituitary is indicated before treatment with bromocriptine mesylate. The appropriate workup and management of hyperprolactinemia includes a complete evaluation of the pituitary to rule out pituitary tumors, as hyperprolactinemia can be a symptom of these tumors.
- Key steps in the workup include:
- Pituitary evaluation: to assess for the presence of pituitary tumors
- Clinical and diagnostic monitoring: to assess the risk of cardiac valvulopathy and other fibrotic complications
- Echocardiogram: to assess the potential presence of valvular disease
- Management should be tailored to the individual patient, with consideration of the potential risks and benefits of treatment with dopamine agonists such as cabergoline or bromocriptine 2, 3.
From the Research
Diagnosis of Hyperprolactinemia
- Hyperprolactinemia is the most common endocrine disorder of the hypothalamic-pituitary axis 4, 5
- The diagnosis of hyperprolactinemia involves a careful history and examination, followed by laboratory tests and diagnostic imaging of the sella turcica 4, 6
- A serum prolactin level is obtained in response to a specific clinical presentation, including symptoms of hyperprolactinemia such as amenorrhea and galactorrhea 6
- An initial level above the normal range should be followed by a repeat level from a blood sample drawn in the morning with the patient in a fasting state 6
Causes of Hyperprolactinemia
- Physiologic, pharmacologic, and pathologic causes of hyperprolactinemia should be considered 5, 7
- Medications and sellar/parasellar masses (prolactin secreting or acting through "stalk effect") are the most common causes of pathological hyperprolactinemia 7
- Pregnancy, primary hypothyroidism, and treatment with drugs that reduce dopaminergic effects on the pituitary are common physiologic and pharmacologic causes of hyperprolactinemia 4, 6
Treatment of Hyperprolactinemia
- Dopamine agonists are the treatment of choice for the majority of patients with hyperprolactinemia 4, 5
- Cabergoline has been shown to be more effective and better tolerated than bromocriptine 4, 5
- Transsphenoidal surgery is usually reserved for patients who are intolerant of or resistant to dopamine agonists or when hyperprolactinemia is caused by non-prolactin-secreting tumors compressing the pituitary stalk 4, 6
- The goals of treatment are to normalize prolactin levels, restore gonadal function, and reduce the effects of chronic hyperprolactinemia 4
Management Strategies
- Treatment mainly aims at restoration and maintenance of normal gonadal function/fertility, and prevention of osteoporosis 7
- Further specific management strategies depend on the underlying cause of hyperprolactinemia 7
- Clinical practice guidelines for the diagnosis and treatment of hyperprolactinemia have been established based on diagnostic criteria and levels of evidence from treatment guidelines, controlled clinical trials, and standardized guides for adolescent and adult population with hyperprolactinemia 8