What investigations should be done in a patient with a history of prior hyperprolactinemia?

From the Guidelines

For a patient with a history of hyperprolactinemia, investigations should include a comprehensive serum prolactin measurement, preferably in a single blood sample collected at any time of day, as recommended by the most recent guidelines 1.

Key Investigations

• A single prolactin measurement is sufficient to assess hyperprolactinemia, but serial measurements over time may be considered to exclude the effect of stress and prolactin pulsatility 1.
• Additional blood tests should evaluate thyroid function (TSH, free T4), renal function, liver function, and pregnancy status in women of childbearing age.
• A medication review is essential as drugs like antipsychotics, metoclopramide, and certain antidepressants can elevate prolactin levels.
• Pituitary MRI with contrast is recommended to detect microadenomas (less than 10mm) or macroadenomas (greater than 10mm) 1.
• Assessment of other pituitary hormones (FSH, LH, estradiol/testosterone, IGF-1, cortisol) should be performed to evaluate for hypopituitarism.
• Visual field testing is necessary if a macroadenoma is present or suspected, particularly if it impinges on the optic chiasm.
• Bone density testing may be indicated in patients with long-standing hyperprolactinemia due to the risk of osteoporosis from hypogonadism.

Considerations

• The diagnosis of hyperprolactinemia requires age-specific and sex-specific prolactin reference ranges and the exclusion of confounding conditions such as hypothyroidism, renal and/or hepatic impairment, and use of medications that cause hyperprolactinemia 1.
• Macroprolactin levels should be assessed where serum prolactin is found to be mildly or incidentally elevated 1.
• The patient's clinical features, such as delayed puberty, galactorrhoea, visual field loss, growth or pubertal arrest, or menstrual disturbance, should be taken into account when deciding on investigations 1. These investigations help determine if the hyperprolactinemia has recurred, identify its cause, assess for complications, and guide appropriate management strategies.

From the FDA Drug Label

Following treatment initiation, clinical and diagnostic monitoring (for example, chest x-ray, CT scan and cardiac echocardiogram) should be conducted to assess the risk of cardiac valvulopathy The recommended frequency of routine echocardiographic monitoring is every 6 to 12 months or as clinically indicated with the presence of signs and symptoms such as edema, new cardiac murmur, dyspnea, or congestive heart failure. Clinical and diagnostic monitoring such as erythrocyte sedimentation rate, chest-x ray, serum creatinine measurements, and other investigations should be considered at baseline and as necessary while patients are treated with cabergoline

In a patient with a history of prior hyperprolactinemia, the following investigations should be done:

• Cardiac evaluation, including echocardiogram to assess the potential presence of valvular disease
• Clinical and diagnostic monitoring, such as:
  • Chest x-ray
  • CT scan
  • Cardiac echocardiogram
  • Erythrocyte sedimentation rate
  • Serum creatinine measurements
• Routine echocardiographic monitoring every 6 to 12 months or as clinically indicated 2

From the Research

Investigations for Prior Hyperprolactinemia

In a patient with a history of prior hyperprolactinemia, the following investigations should be considered:

• Serum prolactin level: to confirm the presence of hyperprolactinemia 3
• Medical history: to eliminate common physiologic and pharmacologic causes of hyperprolactinemia, such as pregnancy, primary hypothyroidism, and treatment with certain drugs 4, 3
• Laboratory tests: to rule out other causes of hyperprolactinemia, such as hypothyroidism 4, 3
• Radiologic imaging of the sella turcica: to establish whether a prolactin-secreting pituitary adenoma or other lesion is present 4, 3, 5
• Pituitary magnetic resonance imaging (MRI): to identify pituitary tumors in patients with persistently elevated prolactin levels 5

Diagnostic Evaluation

The diagnostic evaluation of hyperprolactinemia involves:

• Exclusion of other causes of hyperprolactinemia 4, 3
• Measurement of serum prolactin levels 3
• Radiologic imaging of the sella turcica 4, 3, 5
• Consideration of the patient's medical history, age, sex, and reproductive status 6

Treatment and Management

The treatment and management of hyperprolactinemia depend on the underlying cause and consequences of the condition, and may involve:

• Medical therapy with dopamine agonists, such as cabergoline or bromocriptine 4, 7
• Surgery, in cases where medical therapy is not effective or tolerated 4, 3
• Consideration of the patient's reproductive status and desires 6