Medications used to shrink prolactin-secreting pituitary tumors that can compress the optic nerves.
Drug Class: endocrine
Dopamine agonists like cabergoline and bromocriptine are used to treat prolactin-secreting pituitary tumors (prolactinomas). These tumors can grow large enough to compress the optic chiasm, causing visual field defects. Dopamine agonists can shrink the tumor and restore vision.
Key Takeaways
- First-line treatment for prolactinomas
- Can shrink tumors and restore vision
- Cabergoline is usually preferred (fewer side effects)
- May avoid surgery in many cases
- Long-term treatment often needed
How They Work
Prolactin secretion is inhibited by dopamine. Prolactinomas have dopamine receptors, and dopamine agonists activate these receptors, reducing prolactin production AND shrinking the tumor.
Common Uses
- Pituitary tumors (prolactinomas)
- Can restore visual fields compressed by tumor
- Treats symptoms of high prolactin (irregular periods, milk production)
Medications
Cabergoline (Dostinex)
- Preferred due to better tolerability
- Usually taken twice weekly
- Fewer GI side effects than bromocriptine
Bromocriptine (Parlodel)
- Older medication
- Taken daily
- More side effects
- Less expensive
Expected Benefits
- Tumor shrinkage (often within weeks)
- Visual field improvement
- Prolactin normalization
- May avoid surgery
Side Effects
Common
- Nausea (especially initially)
- Dizziness
- Fatigue
- Nasal congestion
- Headache
Less Common
- Low blood pressure when standing
- Compulsive behaviors (gambling, eating—rare)
- Heart valve changes with high doses (rare, monitor)
Tips for Starting
- Start with low doses
- Take with food to reduce nausea
- Take at bedtime initially
- Increase dose gradually
Monitoring
- Prolactin levels
- MRI to assess tumor size
- Visual fields if optic chiasm involvement
- Echocardiogram for high doses or long-term use
Frequently Asked Questions
Can this replace surgery?
For most prolactinomas, yes. Dopamine agonists are first-line treatment, and most patients don't need surgery. Surgery is reserved for drug failures or intolerance.
How quickly will my vision improve?
Vision may begin improving within days to weeks as the tumor shrinks. Full improvement may take months.
Do I need to take this forever?
Many patients need long-term treatment. Some can eventually taper off, but tumor regrowth is possible. Your endocrinologist will advise.
Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice.
Medically Reviewed Content
This article meets our editorial standards
- Written by:
- Hashemi Eye Care Medical Team
- Medically reviewed by:
- Board-Certified Neuro-Ophthalmologist (MD, Neuro-Ophthalmology)
- Last reviewed:
- January 30, 2025