Key takeaways
- Elevated prolactin has several possible causes, including medicines, pregnancy, an underactive thyroid and pituitary conditions. Endocrine Society overview.
- Some people with raised prolactin and few or no symptoms do not need treatment. The cause and clinical picture guide the decision. Endocrine Society guidance.
- Cabergoline has good evidence for lowering prolactin in appropriate patients, including a trial showing better results than bromocriptine in women with prolactin-related absent periods. Comparative trial.
- Long-term treatment needs a monitoring plan. Product information includes heart-valve and fibrotic-disease precautions. UK Dostinex prescribing information.
- New compulsive gambling, spending or sexual urges can be medicine-related and should be reported, not hidden out of embarrassment. Dostinex safety warnings.
The cabergoline comparison trial enrolled 459 women whose periods had stopped with high prolactin. Of these, 279 had microprolactinomas and 3 had macroprolactinomas; 167 had no identified cause. Raised prolactin had different explanations even within that treatment study. Trial population.
Cabergoline, sold as Dostinex, is considered after investigating the result and symptoms. Some people with few or no symptoms need no treatment.
Does high prolactin mean a pituitary tumour?
Medicines, pregnancy and other hormonal conditions can raise prolactin without a prolactinoma.
The Endocrine Society lists Risperdal, haloperidol, methyldopa and some antidepressants as possible medicine causes. Prolactin also rises normally in pregnancy and breastfeeding; an underactive thyroid or chronic kidney or liver disease can raise it too. Testing for macroprolactin may explain an abnormal result without a health problem. The next investigation depends on the suspected cause: an MRI can show a pituitary tumour and its size when that is suspected. Endocrine Society overview.
Bring the actual laboratory report and a complete medicine list to the appointment. Do not stop a suspected medicine yourself, especially psychiatric treatment. Our thyroid hormone comparison explains another part of endocrine care; it is not a shortcut to identifying the cause of a prolactin result.
How much can cabergoline help?
In the comparison trial, cabergoline normalised prolactin in 83% of women, against 59% with bromocriptine.
Cabergoline is a dopamine agonist: it acts on a signalling pathway that normally restrains prolactin release. In prolactinomas, dopamine-agonist treatment can lower prolactin and reduce tumour size. Endocrine Society treatment information.
In that trial, stable normal prolactin was achieved in 186 of 223 women receiving cabergoline and 138 of 236 receiving bromocriptine. Treatment was double-blind for 8 weeks, then open for a further 16 weeks with adjustments according to response. Cabergoline was also better tolerated. Those figures concern a defined population and comparison, not all causes of raised prolactin or every fertility problem. Cabergoline versus bromocriptine trial.
| What is being followed | Why it matters |
|---|---|
| Prolactin results | Whether the biochemical problem is responding |
| Symptoms and menstrual function | Whether treatment is making a clinical difference |
| Tumour findings, where relevant | Whether the pituitary condition is responding |
| Adverse effects | Whether continuing treatment remains worthwhile |
Why does heart monitoring appear in the leaflet?
Because long-term cabergoline treatment requires attention to valve disease and fibrosis, even when someone feels well.
The UK Dostinex information calls for cardiovascular assessment and an echocardiogram before long-term treatment. It specifies a first follow-up echo within 3 to 6 months and then at least every 6 to 12 months, with the timing based on individual assessment. The specialist should explain the plan that applies to you. Fibrosis can develop gradually, so symptoms alone cannot replace this monitoring. Dostinex prescribing information.
Persistent cough, breathlessness, chest discomfort or new swelling needs assessment. Nausea, dizziness and low blood pressure on standing also occur. In the comparison trial, adverse effects were reported by 68% taking cabergoline and 78% taking bromocriptine; 3% and 12%, respectively, stopped because they could not tolerate treatment. The Dostinex label also warns about sleepiness and sudden sleep episodes: do not drive if affected. Trial and Dostinex warnings.
Can cabergoline affect behaviour or fertility?
Cabergoline can bring back ovulation and can cause new, hard-to-control urges.
The Dostinex warnings include pathological gambling, compulsive buying, increased sexual urges and binge or compulsive eating. They call for regular monitoring and for carers to know about these possible changes. Tell the prescriber about urges that feel unfamiliar or difficult to control; a partner or family member may notice them before you do. Dostinex warnings.
The UK leaflet warns that ovulation may return before the first period. It specifies pregnancy testing at least every 4 weeks while periods are absent. Once periods restart, it recommends a test if one is more than 3 days late. Contraception and plans to conceive belong in the discussion before treatment; contact the treating team if pregnancy occurs. Dostinex pregnancy information.
For the separate question of testosterone treatment and fertility, see enclomiphene versus clomiphene.
Do and don’t
Do:
- Bring the prolactin report and medicines list, including psychiatric treatment, to the review of the cause.
- Ask which symptoms and test results treatment should improve and when the prolactin and heart checks are due.
Don’t:
- Use Dostinex as a general “hormone-balancing” product or stop another medicine yourself.
- Dismiss new gambling, buying, eating or sexual urges that feel hard to control.
