What is the approach to workup and management of galactorrhea?

Galactorrhea Workup and Management

Initial Laboratory Evaluation

Serum prolactin measurement is the essential first test for all patients presenting with galactorrhea, regardless of other symptoms. 1, 2, 3

Core Laboratory Tests

• Prolactin level: Must be obtained in all cases, ideally drawn in the morning while resting to avoid stress-related elevation 4, 2
• Pregnancy test: Mandatory for all premenopausal women before further workup 5, 6
• Thyroid-stimulating hormone (TSH): Required to rule out hypothyroidism, which can cause galactorrhea even with normal prolactin levels 1, 2, 7
• Renal function tests: Assess for chronic renal failure as a secondary cause 2, 5

Special Considerations for Prolactin Testing

• Macroprolactin assessment: Should be performed if prolactin is elevated but clinical features are inconsistent, as macroprolactin is present in 10-40% of hyperprolactinemia cases and has low biological activity 4, 2
• Serial dilutions: For patients with large pituitary lesions but normal or mildly elevated prolactin, perform serial dilutions to detect the "high-dose hook effect" which causes falsely low readings 1, 4, 2
• Repeat measurements: For mildly elevated prolactin, obtain serial measurements at 20-60 minute intervals using an indwelling cannula to exclude stress-related hyperprolactinemia 2

Medication Review

A comprehensive medication review is crucial, as drug-induced hyperprolactinemia is one of the most common causes of galactorrhea. 1, 4, 3

• Medications can cause hyperprolactinemia through direct prolactin stimulation or by antagonizing dopaminergic inhibitory tone 1, 4
• Common culprits include antipsychotics, antiemetics (domperidone), proton pump inhibitors, and certain antidepressants 7, 5
• Discontinue or replace offending medications when clinically feasible 3, 5

Imaging Studies

High-resolution pituitary MRI is the gold standard imaging modality and should be performed when prolactin levels are significantly elevated or when the cause of hyperprolactinemia remains unclear after medication review and laboratory evaluation. 1, 2, 5

Indications for MRI

• Elevated prolactin without identifiable medication or metabolic cause 5, 6
• Visual symptoms or signs of mass effect 1
• Large pituitary lesions on initial imaging 1

Treatment Algorithm Based on Prolactin Levels

Hyperprolactinemia (Elevated Prolactin)

Cabergoline is the preferred first-line medication for treating hyperprolactinemia, as it is more effective and better tolerated than bromocriptine. 4, 8, 5

Cabergoline Dosing

• Initial dose: Up to 2 mg/week for mild hyperprolactinemia 4
• Efficacy: Normalizes prolactin in 60-70% of patients and is superior to bromocriptine with fewer adverse events 4
• Monitoring: Measure prolactin levels 1-3 months after initiating treatment, then every 3-6 months until stabilized 4
• Cardiac surveillance: Perform echocardiography every 5 years for patients on standard doses (≤2 mg/week) to monitor for valvulopathy 4
• Duration: May discontinue after normal prolactin levels maintained for 6 months, with periodic monitoring 1

Bromocriptine Alternative

• Preferred for fertility: Bromocriptine is the preferred agent for hyperprolactin-induced anovulatory infertility 8
• Cabergoline pregnancy consideration: Must be discontinued one month before attempting conception 8
• Efficacy: In clinical trials, bromocriptine suppressed galactorrhea completely in about 75% of cases and reinitiated normal ovulatory cycles within 6-8 weeks on average 9

Prolactinoma-Specific Management

• Medical therapy: Dopamine agonists are first-line treatment for prolactinomas 3, 8
• Surgery: Transsphenoidal surgery reserved for patients who fail high-dose cabergoline, cannot tolerate dopamine agonists, or have persistent symptoms despite medical therapy 5, 6
• Radiation therapy: Rarely required 3, 8

Normoprolactinemic Galactorrhea (Normal Prolactin)

Patients with normal prolactin levels and idiopathic galactorrhea that is not bothersome can be reassured and do not require treatment. 3, 5

• Bothersome symptoms: Those with troublesome galactorrhea usually respond to a short course of low-dose dopamine agonist 3
• No treatment needed: If prolactin and TSH are normal and discharge is not troublesome 5

Additional Hormonal Assessment

• FSH and LH: Consider if amenorrhea is present to evaluate for ovulatory disorders 2
• Assessment for androgen excess: Evaluate for hirsutism and other signs during physical examination 2

Common Pitfalls to Avoid

• Never skip prolactin testing: Even in patients with galactorrhea and no other symptoms, prolactin measurement is mandatory 1, 2
• Don't miss the hook effect: Always perform serial dilutions when measuring prolactin in patients with large pituitary lesions to avoid falsely low results 1, 4, 2
• Don't overlook macroprolactin: Failure to assess for macroprolactin can lead to unnecessary treatment of laboratory hyperprolactinemia without true clinical disease 4, 2
• Don't dismiss mild elevations: Even mild hyperprolactinemia can cause menstrual disturbances and requires proper evaluation 4
• Don't forget hypothyroidism: Galactorrhea can occur in clinically euthyroid patients; dynamic thyroid function tests may be needed 7

Monitoring During Treatment

• Prolactin levels: Assess treatment efficacy by measuring prolactin 1-3 months after starting therapy 1, 4
• Side effects: Monitor for gastrointestinal intolerance, postural hypotension, and psychological effects with dopamine agonists 4
• Menstrual function: Document restoration of menses, which typically occurs in 77% of women treated with cabergoline 10