Prolactinoma

A prolactinoma is a small benign (non‑cancerous) growth in the pituitary gland in the brain.

The pituitary gland produces hormones which act as chemical messengers throughout the body. If you have a prolactinoma, the gland produces too much of a hormone called prolactin.

Symptoms

Excess prolactin can cause a variety of symptoms.

In women

irregular or no periods
reduced fertility
milk leakage from the breasts

In men

erectile dysfunction
reduced fertility
breast enlargement

Occasionally, larger growths can cause pressure in the brain, leading to:

headaches
visual disturbance

How are prolactinomas treated?

Tablet medications are the main treatment.

These include:

cabergoline
bromocriptine
quinagolide

These medications:

lower prolactin levels
reduce the size of the growth

They are effective in over 90% of patients.

Occasionally, if medication does not work or the prolactinoma is large, surgery may be an option.

How long is treatment needed?

Treatment is usually required for at least 2 years.

These medications are safe to take for many years
Stopping treatment can lead to prolactin levels rising again
It is not possible to predict who will relapse

Because of this, you will need:

close follow‑up
repeat blood tests after stopping treatment

Starting treatment

Most people tolerate these medications well.

Treatment usually starts at a low dose
The dose is increased gradually as needed

Side effects

Possible side effects include:

abdominal pain
nausea
heartburn or indigestion
constipation or diarrhoea
headache
dizziness

To help reduce side effects:

take medication with food
consider taking it in the evening before bed

Heart monitoring

If you are prescribed cabergoline or bromocriptine, your doctor may arrange a heart scan (echocardiogram).

This is because:

rare heart valve problems have been reported in people taking these medicines at higher doses
this has not been reported in people treated for prolactinoma at lower doses

The scan is sometimes carried out as a precaution.

Behaviour changes (rare)

These medications increase dopamine levels in the brain.

Very rarely, this can affect behaviour.

You should tell a doctor if you or someone close to you notices unusual behaviour that you cannot control.

This may include:

a strong impulse to gamble excessively
excessive internet use
increased sex drive or changes in sexual behaviour
binge eating or compulsive eating
uncontrollable excessive shopping or spending

You may be more at risk if you have a previous history of these behaviours, but this is still rare.

Because you may not notice these changes yourself, it is recommended that you tell someone close to you (such as a family member or friend) that you are taking this medication.

They should seek medical advice if they notice any changes.