Alternative to Cabergoline for Hyperprolactinemia
Bromocriptine is the first-line alternative when cabergoline is unavailable, dosed at 2.5 mg twice daily for most patients, with gradual titration from a lower starting dose to minimize side effects. 1, 2
Initial Dosing Strategy
- Start bromocriptine at a low dose (1.25 mg at bedtime) and gradually increase to the target dose of 2.5 mg twice daily to reduce gastrointestinal intolerance and postural hypotension 3, 4
- For macroprolactinomas, doses may need to be increased to 5 mg twice daily 5
- Taking the medication with food or while recumbent further minimizes adverse effects 3
Expected Efficacy Compared to Cabergoline
- Bromocriptine normalizes prolactin levels in approximately 58-59% of patients, compared to 83% with cabergoline 5, 6
- Restoration of ovulatory cycles occurs in 52% of women on bromocriptine versus 72% with cabergoline 6, 7
- Tumor shrinkage and symptom resolution still occur with bromocriptine, though less reliably than with cabergoline 4
Tolerability Profile
- Adverse events occur in 52-72% of bromocriptine-treated patients compared to only 12-52% with cabergoline 3, 5
- The most common side effects are gastrointestinal (nausea, vomiting), cardiovascular (postural hypotension), and neurological (headache, dizziness) 3
- Up to 12% of patients cannot tolerate bromocriptine at therapeutic dosages and will require switching to an alternative 3
Important Clinical Caveats
- For women seeking fertility treatment, bromocriptine remains preferred over cabergoline in many centers due to more extensive safety data in pregnancy, despite cabergoline's superior efficacy and tolerability 3, 6
- Bromocriptine requires twice-daily dosing compared to cabergoline's once or twice weekly schedule, which may affect adherence 4, 6
- Monitor for the same psychological side effects (mood changes, depression, impulse control disorders) that occur with all dopamine agonists 2
Monitoring Requirements
- Check serum prolactin levels every 3-6 months while on stable therapy 1, 8
- For macroprolactinomas, obtain repeat MRI 3-6 months after starting treatment 1
- Watch for cerebrospinal fluid leak (rhinorrhea) in patients with tumors invading the sphenoid bone, as tumor shrinkage can precipitate this complication 2, 8