What is the treatment for hyperprolactinemia (elevated prolactin) in males?

Treatment of Hyperprolactinemia in Males

Dopamine agonists are the first-line treatment for hyperprolactinemia in males, with cabergoline being the preferred agent due to its superior effectiveness and better tolerability profile. 1

Diagnostic Evaluation

Before initiating treatment, a proper diagnostic workup should be performed:

1. Confirm hyperprolactinemia:

   • Measure serum prolactin levels (a single measurement is usually sufficient) 1
   • For mildly elevated levels (up to 5x upper limit of normal), consider repeat testing to rule out stress-induced elevation 1

2. Determine etiology:

   • Measure luteinizing hormone (LH) levels 1
   • Check for medications that can cause hyperprolactinemia (antipsychotics, antidepressants, opioids) 1
   • Rule out secondary causes:
     • Hypothyroidism (check thyroid function)
     • Renal or hepatic impairment
     • Pituitary stalk compression

3. Imaging:

   • MRI of the pituitary is indicated when prolactin levels are persistently elevated 1
   • For patients with very low total testosterone (<150 ng/dL) and low/normal LH, pituitary MRI is recommended regardless of prolactin levels 1

Treatment Algorithm

First-Line Treatment: Dopamine Agonists

1. Cabergoline (preferred option):

   • Starting dose: 0.25-0.5 mg once or twice weekly
   • Superior efficacy and better tolerability compared to other dopamine agonists 2, 3
   • Normalizes prolactin levels and induces tumor shrinkage in most cases 4
   • Advantages: longer half-life, fewer side effects, weekly dosing

2. Bromocriptine (alternative):

   • If cabergoline is not available or not tolerated
   • Requires more frequent dosing (typically twice daily)
   • More side effects than cabergoline 2

Monitoring

• Measure prolactin levels after 1 month of treatment
• For macroprolactinomas: MRI after 3 months to verify tumor shrinkage 2
• Echocardiographic monitoring every 6-12 months for patients on cabergoline to assess for cardiac valvulopathy 5
• Monitor for resolution of symptoms (sexual dysfunction, gynecomastia)

Special Considerations

1. Fertility concerns:

   • Males with hyperprolactinemia interested in fertility should have a reproductive health evaluation prior to treatment 1
   • Dopamine agonists can restore fertility in many cases by normalizing testosterone and gonadotropin levels

2. Resistant cases:

   • If one dopamine agonist fails, try switching to another 2
   • Consider surgical consultation for dopamine agonist-resistant prolactinomas

3. Duration of treatment:

   • Long-term therapy is often required, but dose reduction may be attempted after several years of normal prolactin levels 2
   • After prolonged treatment, approximately 20-30% of patients maintain normal prolactin levels after discontinuation 2

Potential Side Effects and Management

Cabergoline

• Common: Nausea, headache, dizziness, fatigue
• Serious: Cardiac valvulopathy (primarily with higher doses used for Parkinson's disease) 5
• Management: Take with food to reduce gastrointestinal side effects, start with low dose and titrate slowly

Bromocriptine

• Common: Nausea, vomiting, dizziness, orthostatic hypotension
• Management: Start with very low dose (1.25 mg) at bedtime, gradually increase, take with food

Alternative Approaches

1. Surgery (transsphenoidal resection):

   • Reserved for patients who:
     • Do not respond to dopamine agonists
     • Cannot tolerate medical therapy
     • Have very large tumors with significant mass effect 4

2. Radiation therapy:

   • Third-line option when both medical therapy and surgery fail 4

Clinical Pearls

• Erectile dysfunction in men with hyperprolactinemia is often due to secondary hypogonadism and typically improves with normalization of prolactin levels 6
• For drug-induced hyperprolactinemia where the causative medication cannot be withdrawn, dopamine agonist therapy may be unnecessary or potentially harmful 2
• The "hook effect" can cause falsely low prolactin readings in very large prolactinomas; serial dilutions should be performed if clinical suspicion is high despite only modestly elevated prolactin 1

By following this treatment approach, most males with hyperprolactinemia can achieve normalization of prolactin levels, resolution of symptoms, and improvement in quality of life.