Medication for Pituitary Tumors

Doctors often use medication to manage hyperprolactinemia, in which there is too much prolactin in the blood. This causes fertility problems, erectile dysfunction, and loss of sex drive. The condition occurs as a result of a pituitary tumor called a prolactinoma. Doctors may prescribe medications called dopamine agonists, which stop prolactinomas from producing too much prolactin and cause the tumor to shrink.

These medications are often effective enough that surgery to remove the tumor is unnecessary. They can shrink tumors that are pressing on the nerves that run between the eyes and the brain, called the optic nerves. This can help improve a person’s vision. The medications can also regulate hormone levels in people with fertility problems, enabling them to have children.

Some people may need to take these medications for several years or for the rest of their lives to keep the tumor under control. Some people with smaller tumors can eventually stop taking medication. Side effects may include nausea, sleepiness, headaches, nightmares, sinus congestion, and dizziness, though these may subside over time as the body adjusts to the medication.

Medications are not usually the first treatment prescribed for pituitary tumors that cause Cushing’s disease. They can be used if tumors return after surgery, however. Sometimes medications are given at the same time as radiation therapy.

Cushing’s disease causes the pituitary gland to produce too much adrenocorticotropic hormone, which signals the adrenal glands to make excessive amounts of cortisol.

For this reason, doctors may use medications, such as a class of drug called a somatostatin analogue, to prevent the pituitary gland from producing too much adrenocorticotropic hormone. They are given by injection under the skin or into muscle. The frequency of the injection varies by the medication used. It may be daily, weekly, or even monthly.

Doctors may also use medications that block one or more adrenal enzymes involved in making cortisol. These medications are called adrenal enzyme inhibitors and are taken by mouth each day, although intravenous (IV) infusion is an option for people who are hospitalized.

A glucocorticoid-receptor antagonist can block cortisol from working in the body. Doctors may use it help manage hyperglycemia, or high blood sugar, which is associated with Cushing’s disease. This medication is taken daily by mouth.

Another type of medication, called an adrenolytic agent, reduces cortisol levels by destroying the adrenal glands. This medication is taken by mouth each day for the rest of your life.

Because the medications used to treat Cushing’s disease can greatly lower cortisol in the body, doctors may also prescribe steroids to bring the cortisol level back to a healthy range. You can live without functioning adrenal glands if you take cortisone medication.

Medication used to treat Cushing’s disease may cause nausea, vomiting, or diarrhea. Your doctor can manage these side effects by changing the dose or prescribing other medications.

Sometimes a pituitary tumor that releases growth hormone, causing acromegaly, cannot be completely removed with surgery and hormone levels remain high. Occasionally, dopaminergic agonists are used to shrink the pituitary gland and decrease growth hormone secretion.

To help the tumor shrink, your doctor may prescribe a type of medication called a somatostatin analog, which helps prevent a pituitary tumor from releasing growth hormone.

These medications are available as injections given under the skin daily or once a month. They can be given by a doctor or taken at home. While uncommon, side effects may include nausea, vomiting, diarrhea, elevated blood sugar, and gall bladder problems. To help manage these side effects, a doctor can adjust the dose or give you other medications.

Another medication is a growth hormone antagonist, which blocks the action of growth hormone on the body’s tissues. It does not, however, prevent the pituitary gland from releasing the hormone, and it does not shrink a tumor. It is given as an injection under the skin each day. This medication is well tolerated, although it can cause low blood sugar in some people. Low blood sugar can be managed through diet and other medications.

Doctors may also prescribe another medication, a dopamine agonist, which is taken by mouth. Similar to somatostatin analogs, it can block the release of growth hormone secretion in some people and may help shrink pituitary tumors. Common side effects include nausea and lightheadedness.

Doctors often need to prescribe medication to replenish the hormones that are no longer produced when a pituitary tumor has disrupted hormone production. They may also need to perform surgery or use radiation therapy.

The types of medications prescribed vary for each person and depend on the particular hormone shortage in the body.

If you have a shortage of adrenocorticotropic hormone, or ACTH, due to a pituitary tumor, your adrenal gland may not produce enough cortisol, which helps your body respond to stress. To increase your cortisol levels, a doctor can prescribe synthetic corticosteroid medications, such as hydrocortisone or prednisone. They are taken by mouth every day.

If you have low levels of thyroid-stimulating hormone, or TSH, your thyroid may not produce enough thyroxine, creating problems with metabolism. A doctor may prescribe a synthetic thyroid hormone to replace thyroxine. It is taken by mouth daily.

Low levels of follicle-stimulating hormone, or FSH, and luteinizing hormone, or LH, can lead to low levels of sex hormones in men and women. To help raise these levels, doctors may prescribe testosterone to men and estrogen with or without progesterone to women. Progesterone, another female sex hormone, is often given to offset some of the negative effects of estrogen, such as an increased thickening of the lining of the uterus which can lead to an increased risk of cancer.

Testosterone is given as an injection, a patch, or a gel. Female hormone replacement can be administered with pills taken by mouth, gels, or patches. The treatment schedule for these varies, depending on which option you use.

If a person has become infertile due to low hormone levels, a doctor can prescribe injections of FSH and LH to stimulate the menstrual cycle in women and sperm production in men. Sometimes an anti-estrogen drug may also be used to stimulate pituitary FSH and LH secretion in women or men.

Low levels of growth hormone in adults can be replaced with synthetic growth hormone to help manage symptoms such as decreased energy and increased fat around the abdomen. This medication is injected under the skin on a daily basis and can be taken at home.

A deficiency of antidiuretic hormone, or ADH, also called vasopressin, which allows the kidney to concentrate urine and retain needed body water, causes a condition called diabetes insipidus. People who have this condition, which is a rarely seen as a symptom of a pituitary adenoma, excrete a large amount of urine, resulting in excessive thirst. A doctor can give a daily hormone replacement that can be taken by mouth or through a nasal spray.

For rare pituitary tumors that produce too much thyroid-stimulating hormone, causing secondary hyperthyroidism, doctors may prescribe medications that can lower production of thyroid-stimulating hormone, or TSH, shrinking the tumor. These are available as injections, which are given under the skin once a month either by a doctor or at home. Radiation therapy or surgery are often necessary to manage these tumors.

Pituitary tumors are almost never cancerous. In the rare instances when they are, surgery and radiation therapy are the main treatments.

It is not known whether chemotherapy, a group of drugs used to destroy cancer cells throughout the body, is effective for pituitary cancer. Your doctor may recommend that you participate in a clinical trial of different combinations of chemotherapy and newer targeted drugs, which are designed to destroy cancer cells while sparing much of the body’s healthy tissue. You and your doctor can discuss whether a clinical trial is right for you.