What is the initial treatment for hyperprolactinemia?

Initial Treatment for Hyperprolactinemia

Dopamine agonists are the first-line treatment for hyperprolactinemia, with cabergoline preferred due to its better efficacy and tolerability at a starting dose of 0.25-0.5 mg/week. 1

Diagnostic Evaluation Before Treatment

Before initiating treatment, it's essential to:

• Confirm hyperprolactinemia with prolactin measurement using age-specific and sex-specific reference ranges 1
• Review medications that can cause hyperprolactinemia (especially antipsychotics) 1
• Check thyroid function (TSH, free T4) as hypothyroidism is a common cause 1
• Perform imaging (preferably MRI) to evaluate for pituitary lesions 1
• Consider the "high-dose hook effect" in patients with large pituitary lesions but only mildly elevated prolactin 1

Treatment Algorithm

First-line Treatment: Dopamine Agonists

1. Cabergoline:

   • Preferred agent due to superior efficacy and tolerability 1
   • Starting dose: 0.25-0.5 mg/week 1
   • Advantages: Once or twice weekly dosing, better side effect profile
   • Monitor prolactin levels 1 month after starting treatment 1

2. Bromocriptine:

   • Alternative if cabergoline is unavailable or contraindicated
   • Usually given once or twice daily 2
   • More frequent side effects including nausea and orthostatic dizziness 2

Monitoring and Dose Adjustment

• Check prolactin levels 1 month after starting treatment 1
• Adjust dose based on prolactin response and side effects 1
• Perform cardiovascular evaluation including echocardiogram at treatment initiation 1, 3
• Provide yearly echocardiography for patients receiving >2 mg/week cabergoline and every 5 years if on ≤2 mg/week 1, 3
• For macroprolactinomas, perform MRI after 3 months of treatment to verify tumor size reduction, then after 1 year, yearly for 5 years, and once every 5 years if stable 4

Special Considerations

Cardiac Monitoring

• Monitor for cardiac valvulopathy, especially with higher doses of cabergoline 1, 3
• Discontinue treatment if fibrotic changes are diagnosed or suspected 3
• Use the lowest effective dose for hyperprolactinemic disorders 3

Pregnancy

• Discontinue dopamine agonists during pregnancy unless there's a risk of tumor expansion 1, 3
• Close monitoring is recommended during pregnancy due to potential tumor growth 1
• Dopamine agonists should not be used in pregnancy-induced hypertension unless benefit outweighs risk 3

Treatment Resistance

• If resistance to one dopamine agonist occurs, try switching to another 4
• For resistant or aggressive prolactinomas, consider surgical evaluation 5

Potential Side Effects and Complications

Cabergoline

• Cardiac valvulopathy (more common with doses >2mg/day) 3
• Pleural, pericardial, and retroperitoneal fibrosis (rare) 3
• Hypotension 3

Bromocriptine

• Nausea, orthostatic dizziness 2
• Symptomatic hypotension 6
• Headache 6
• Rare serious adverse events in postpartum women: hypertension, seizures, stroke 6

Treatment Goals

• Normalize prolactin levels
• Restore gonadal function
• Reduce tumor size (if present)
• Preserve pituitary function
• Prevent osteoporosis 1

Common Pitfalls to Avoid

1. Failing to rule out medication-induced hyperprolactinemia before initiating treatment
2. Not performing baseline cardiac evaluation before starting dopamine agonists
3. Using excessive doses of cabergoline (>2mg/week) without appropriate cardiac monitoring
4. Continuing dopamine agonists during pregnancy without clear indication
5. Not monitoring for signs of fibrotic complications during long-term treatment