Your doctor will tailor the treatment of your hyperprolactinaemia based on your symptoms and test results. Some people do not require any treatment, while others may require medication and/or surgery. Prolactinomas often stay the same size for many years and if they grow, they do so very slowly. The treatment plan will depend on the cause of your hyperprolactinaemia.
If the hyperprolactinemia is due to medications you are taking, your doctor will discuss whether you can stop taking the medication, or whether an alternative exists that will not increase your prolactin levels. Sometimes your medications cannot be changed, in which case your doctor will discuss other options with you.
If the hyperprolactinemia is due to hypothyroidism, your doctor will treat the hypothyroidism first, and monitor your prolactin levels to make sure they return to normal.
The first step in treatment is generally medication, but if there are no symptoms and only a very mild elevation in prolactin level, no treatment may be necessary. Surgery and radiation therapy are occasionally used to control prolactinomas that continue to grow despite medication or where the medications cause troublesome side effects.
The medication used to treat prolactinoma is called a dopamine agonist. Commonly used dopamine agonist medications include cabergoline (trade name, Dostinex), bromocriptine (trade name, Parlodel) and quinagolide (trade name, Norprolac). Dopamine agonists act like dopamine, causing the pituitary gland to make less prolactin. In many people, prolactin levels return to normal within a few weeks to a few months of starting treatment. It usually takes longer to see a reduction in the size of the prolactinoma.
You will need to continue taking the medication as prescribed. Otherwise, the prolactinoma can grow and/or symptoms can return. In many cases, you will need to keep taking the medication for a long period of time. In some cases, the medication can eventually be reduced or even stopped. Your doctor will regularly measure your hormone levels to make sure the dose is correct, and the medication is working.
Your doctor will generally start you on a low dose and may increase the dose over time. This can help avoid any side effects, including nausea, nasal stuffiness, dizziness/faintness, constipation, sleepiness, headache, worsening of anxiety and/or depression. Rare side effects can include addictive behaviours (e.g. involving sexual activity, gambling, shopping or eating), auditory hallucinations (hearing things), mood changes and delusions. You should notify your doctor as soon as possible if these rarer side effects occur as they may recommend that you reduce or stop your medication. These side effects usually resolve very quickly once medication is stopped. Other treatments may be considered if the prolactinoma is still present.
In other medical conditions where cabergoline is used in higher doses it can cause scarring of the heart valves leading to heart failure. However, current evidence suggests that cabergoline does not cause heart valve scarring in the low doses usually used to treat hyperprolactinaemia.
In women, successful treatment usually results in restoration of fertility (particularly in microprolactinomas). To prevent unwanted pregnancy, birth control may be needed. In women with microprolactinomas who do not wish to fall pregnant in the near future, the oral contraceptive pill may be used instead of dopamine agonist medications in order to restore normal sex hormone (oestrogen and progesterone) levels and improve bone density.
If you are pregnant or planning to get pregnant, your doctor may change your medication. In microprolactinomas, the medication can often be stopped once you are pregnant. If surgery is required – for instance, in large prolactinomas – your doctor may try to arrange for this to occur well before any planned pregnancies. It is helpful to discuss any plans for children with your doctor ahead of when you start trying to conceive.
Most prolactinomas respond to medication, and do not require surgery. Surgery may be needed if the prolactinoma is large and pressing on nerves or brain tissue or is growing despite medication or if the medication is not tolerated. There are two types of surgery to remove prolactinomas. Your surgeon will choose the best method based on the size and extent of the prolactinoma.
Transnasal transsphenoidal surgery is the most common procedure. This surgery is often done by two surgeons: a neurosurgeon; and an ear, nose and throat (ENT) surgeon. The ENT surgeon uses an endoscope (a very thin fibre optic tube with a camera on the end) to navigate through one of your nostrils to the back of the nose where a small cut is made to access the pituitary gland. The ENT surgeon uses the endoscope to assist the neurosurgeon to see and remove the tumour. Larger tumours may need to be removed in smaller pieces. Once the tumour is removed a piece of tissue from the inside of your nose or some fat tissue is used to patch the hole at the back of the nose. This surgery leaves no visible scars.
The surgery takes about 2-3 hours and you will stay in hospital for 3-5 days. During your hospital stay your urine output is watched carefully and you may be prescribed some steroid medication for a few days. You will have regular blood tests while in hospital. After surgery, it is fairly common to have a mild headache and nasal congestion for up to 2 weeks. You will have another blood test 4-6 weeks after surgery to check your prolactin and other hormones levels. Thereafter, your prolactin and hormone levels will be checked periodically. An MRI scan will be done after 3-6 months. If symptoms reappear, blood tests and scanning will be repeated.
Transcranial surgery is when the pituitary is operated on through a cut in the forehead. It is only rarely performed in very large prolactinomas, which can make it difficult to remove all the tumour through the back of the nose.