Treatments and drugs
Goals in the treatment of prolactinoma include:
- Return the production of prolactin to normal levels
- Restore normal pituitary gland function
- Reduce the size of the pituitary tumor
- Eliminate any signs or symptoms from tumor pressure, such as headaches or vision problems
- Improve quality of life
Prolactinoma treatment consists of two main therapies: medications and surgery.
Oral medications often can decrease the production of prolactin and eliminate symptoms. Medications may also shrink the tumor. However, long-term treatment with medications is generally necessary.
Doctors use drugs known as dopamine agonists to treat prolactinoma. These drugs mimic the effects of dopamine — the brain chemical that normally controls prolactin production — but are much more potent and long lasting. Commonly prescribed medications include bromocriptine (Cycloset, Parlodel) and cabergoline. These drugs decrease prolactin production and may shrink the tumor in most people with prolactinoma.
Medication during pregnancy
Bromocriptine is the preferred drug when treating women who want to restore their fertility. However, once you become pregnant, your doctor will likely advise you to stop taking either medication.
Although both drugs are considered safe in early pregnancy, their safety throughout pregnancy isn't known. However, if you have a large prolactinoma or you develop signs and symptoms such as headaches or vision changes, your doctor may recommend that you restart your medication to prevent complications from the prolactinoma.
If you're being treated for prolactinoma and you'd like to start a family, it's best to discuss your options with your doctor before you become pregnant.
Common side effects
Nausea and vomiting, nasal stuffiness, headache, and drowsiness are common side effects of these medications. However, these side effects often can be minimized if your doctor starts you with a very low dose of medication and gradually increases the dose.
Cabergoline is the preferred treatment because it appears to be more effective than bromocriptine. It also has less frequent and less severe side effects. However, it's more expensive than bromocriptine and it's newer, so its long-term safety record isn't as well-established.
There have been rare cases of heart valve damage with cabergoline, but usually in people taking much higher doses for Parkinson's disease. Some people may also develop compulsive behaviors, such as gambling, while taking these medications.
If medication shrinks the tumor significantly and your prolactin level remains normal for two years, you may be able to taper off the medication with your doctor's guidance. However, recurrence is common. Don't stop taking your medication without your doctor's approval.
If drug therapy for prolactinoma doesn't work or you can't tolerate the medication, surgery to remove the tumor may be an option. Surgery may be necessary to relieve pressure on the nerves that control your vision.
The type of surgery you have will depend largely on the size and extent of your tumor:
- Transsphenoidal surgery. Most people who need surgery have this procedure, in which the tumor is removed through the nasal cavity. Complication rates are low because no other areas of the brain are touched during surgery, and this surgery leaves no visible scars.
- Transcranial surgery. If your tumor is large or has spread to nearby brain tissue, you may need this procedure, also known as a craniotomy. The surgeon reaches the tumor through the upper part of the skull.
The outcome of surgery depends on the size and location of the tumor and your prolactin levels before surgery, as well as the skill of the surgeon. The higher the prolactin level, the slimmer the chance that prolactin production will return to normal after surgery.
Surgery corrects the prolactin level in most people with small pituitary tumors. However, many pituitary tumors come back within five years of surgery. For people with larger tumors that can only be partially removed, drug therapy often can return the prolactin level to a normal range after surgery.
For people who don't respond to medication and aren't candidates for surgery, radiation therapy may be an option.