What is the treatment for elevated prolactin levels?

Treatment for Elevated Prolactin Levels

Cabergoline is the preferred first-line treatment for hyperprolactinemia due to its superior effectiveness and tolerability, with initial dosing starting at 0.25-0.5 mg/week. 1

Diagnostic Evaluation Before Treatment

Before initiating treatment, it's essential to:

1. Determine the cause of hyperprolactinemia:

   • Rule out physiological causes (pregnancy)
   • Check medication history (antipsychotics are common culprits) 2
   • Evaluate for primary hypothyroidism (check TSH, free T4)
   • Rule out renal failure
   • Consider macroprolactinemia (occurs in up to 40% of cases) 3
   • Assess for symptoms: menstrual disturbances, galactorrhea, visual field loss, hypogonadism 1

2. Determine prolactin level severity:

   • Values >250 ng/mL strongly suggest prolactinoma 3
   • Values <100 ng/mL may indicate medication effect, macroprolactinemia, or systemic disease
   • Consider "hook effect" in large pituitary adenomas (≥3 cm) with unexpectedly low prolactin 3

Treatment Algorithm

First-Line Treatment: Dopamine Agonists

1. Cabergoline (preferred):

   • Initial dose: 0.25-0.5 mg/week 1
   • Can be gradually increased up to 3.5 mg/week or up to 7 mg/week in exceptional cases
   • Advantages: Better efficacy, tolerability, and longer half-life (once or twice weekly dosing) 1, 4
   • Monitor: Check prolactin levels 1 month after starting treatment 1

2. Bromocriptine (alternative):

   • Consider when pregnancy is desired or planned, as it has more safety data in pregnancy 5
   • Mechanism: Dopamine receptor agonist that inhibits prolactin secretion 6
   • Disadvantage: Shorter half-life requiring daily dosing, more side effects 4

Monitoring and Follow-up

• Prolactin levels: Check 1 month after starting treatment, then adjust dose based on response 1
• Cardiac monitoring: For patients on cabergoline:
  • Initial echocardiogram at treatment initiation
  • Yearly echocardiography if receiving >2 mg/week
  • Every 5 years if on ≤2 mg/week 1
  • Watch for cardiac valvulopathy, especially at higher doses 7
• Treatment goals:
  • Normalize prolactin levels
  • Restore gonadal function
  • Reduce tumor size (if present)
  • Preserve pituitary function
  • Prevent osteoporosis 1

Special Considerations

• Pregnancy: Discontinue dopamine agonists unless there's risk of tumor expansion 1, 7
• Medication-induced hyperprolactinemia: Consider stopping the offending medication or switching to an alternative 2
• Macroprolactinoma: More aggressive treatment may be needed due to risk of tumor growth 8
• Asymptomatic microprolactinoma: May not require treatment, just regular monitoring 8

Important Caveats and Pitfalls

• Cardiac valvulopathy risk: Cabergoline at doses >2 mg/day has been associated with cardiac valvulopathy, particularly in Parkinson's disease patients. The risk appears lower in hyperprolactinemia treatment, which typically uses lower doses 7

• Fibrotic complications: Monitor for signs of pleuro-pulmonary disease, renal insufficiency, or cardiac failure, which may indicate fibrotic reactions 7

• Medication side effects: Take dopamine agonists with food to reduce nausea and vomiting 6

• Drug interactions: Bromocriptine has high affinity for CYP3A4; inhibitors might increase bromocriptine levels 6

• Misdiagnosis risk: Ensure proper diagnosis before treatment, as macroprolactinemia and hook effect can lead to inappropriate management 3

• Treatment duration: Consider gradual tapering of dopamine agonist to the lowest effective dose after several years, as some patients may be able to discontinue medication 8