Hyperprolactinemia

What is Hyperprolactinemia?

Hyperprolactinemia is an abnormal medical condition in which the body produces excessive prolactin. Prolactin is produced by a small pea-sized hormone-secreting gland, the pituitary gland, situated at the base of the neck.

It helps in body functions like the formation of blood cells, reproduction, ovulation, and immunity and stimulates breast milk production, also called lactation. It can cause severe damage to the body, such as osteoporosis and infertility. Hyperprolactinemia also affects sex hormone levels- estrogen and testosterone in women and men, respectively. The level of prolactin is generally high during pregnancy. The basic range of prolactin in females is less than 25 ng/ml; in males, it is less than 20 ng/ml, and in pregnant females, it ranges from 80-400 ng/ml. Hence, all this leads to hyperprolactinemia.

Causes

Several causes of hyperprolactinemia include high blood pressure, nausea, disease of gastroesophageal reflux, vomiting, extreme pain, certain mental disorders, symptoms of menopause, heartburn, birth control pills, and depression. However, these symptoms are caused due to some medications resulting in a high level of prolactin.

Some other causes include pregnancy as well as lactation problems, injuries of the chest wall, diseases and a tumor of the pituitary gland, deficiency of thyroid hormone or underactive thyroid, and diseases of the liver and kidney. Some antidepressants-desipramine and clomipramine, medications like Verelan, Isoptin, Calan, cimetidine, Primperan, and Reglan, are also responsible for hyperprolactinemia. 

Other uncommon causes involve trauma and infection of the hypothalamus, high levels of cortisol hormone, which leads to Cushing syndrome, and scarring of the liver or cirrhosis.

Symptoms

Symptoms are different in men and women.

• In males: infertility, frequent headaches, reduction in body hair and muscle mass, growth of breast, also called gynecomastia, erectile dysfunction, changes in vision, lactation, and lack of sexual desire.
• In females: irregular menstrual flow or pause in the menstrual cycle, lactation problems, that is, the production of milk even during non-pregnancy, infertility, dryness in the vagina, libido loss, and breast pain.

How is hyperprolactinemia diagnosed?

Primary tests include detecting the level of prolactin in blood based on galactorrhea or infertility. It is also applicable to men. If the secretion of prolactin is high, then thyroid tests are conducted. X-ray of the pituitary gland is done to highlight the presence of macro-adenoma. MRI can be employed to diagnose the size of a tumor. These are frequent tests for checking the growth of a tumor. CT scan is another essential measure to generate images of the gland though it is less clear than an MRI scan. If the growth of hormones is abnormal, then damage to adjacent tissues is expected. Hence an eye check-up is necessary.  

How is hyperprolactinemia treated?

Sometimes hyperprolactinemia shows no indications and hence does not require any treatment. Types of treatment involve medications, synthetic thyroid hormones, and radiation surgery. Depending on the severity, medicines prescribed for tumors, such as cabergoline and bromocriptine, are used. These medicines have a long-lasting effect in treating hyperprolactinemia in its early stages. For chronic hyperprolactinemia, surgery is a must. Radiation therapy is used to reduce the size of the tumor by reducing the prolactin levels. Different types of radiation are used according to the location and size of the tumor.

Hyperprolactinemia infertility

Hypersecretion and microadenomas of prolactin mainly result in infertility, galactorrhea, and amenorrhea. This condition is similar in the case of men, which results in infertility and hypogonadism. The common medication is dopamine, cabergoline, and bromocriptine. The aim is to achieve fertility, reduce the tumor size, and neutralize the level of prolactin. 

• Bromocriptine: is proven effective in restoring fertility in almost 75%-90% of patients diagnosed with microadenomas. However, it has minor side effects, such as nausea, fatigue, and headache. 
• Cabergoline: it is a widely prescribed medication for women trying to conceive a baby. It can be used with bromocriptine for better results and safety.
• Dopamine: it is used against intolerance and pain. It ceases pain and has proved effective in 20%-30% of patients.

How does hypothyroidism cause hyperprolactinemia?

Early stages of hypothyroidism can raise the level of prolactin by increasing the level of thyroid-releasing hormone. According to the study, in almost 30% of patients, varying levels of serum prolactin are diagnosed. It is characterized by normal thyroid hormone with high thyroid-releasing hormone. Symptoms of hypothyroidism are fatigue, intolerance to colds, and musculoskeletal problems. Subclinical and primary are two categories of hypothyroidism. Disorders of cardiovascular, metabolic, and musculoskeletal are common in both. Elevation of serum prolactin was first diagnosed in 1988 in a female with subclinical hypothyroidism and carpal tunnel syndrome, which eventually resulted from hyperprolactinemia.

Idiopathic Hyperprolactinemia

Idiopathic hyperprolactinemia is a condition in which elevated serum prolactin levels are present in a patient. In this condition, there are no previous symptoms of diseases of the nervous system and pituitary gland. Idiopathic hyperprolactinemia can occur due to dopamine resistance or macroprolactinomas. It is non-cancerous and does not spread rapidly. The symptoms of early-stage idiopathic hyperprolactinemia can be cured using bromocriptine. 

Risperidone Hyperprolactinemia

Risperidone is of two types- typical and atypical antipsychotic. Atypical antipsychotics can lead to hyperprolactinemia. Medications are necessary to reduce the symptoms and side effects of hyperprolactinemia.

Which antipsychotic drugs cause hyperprolactinemia?

Antipsychotic actions are the outcome of the opposition of dopamine which involves a reduction of delusions. Antipsychotic agents raise the level of serum prolactin by inhibiting dopamine in the system of the hypothalamus. The pituitary gland is provided with dopamine through the pituitary veins system to the basal hypothalamus and periventricular. This dopamine provides a stimulus to the cells of the lactotroph pituitary. Along with this, thyroid-releasing hormone, vasoactive intestinal, oxytocin and peptide histidine-methionine promote the secretion of prolactin. Atypical antipsychotic dose hinders unselected dopamine in the brain.

How does empty sella syndrome cause hyperprolactinemia?

Empty sella syndrome is defined as the malformation or enlargement of a skull structure, also called sella turcica. It is in the shape of a saddle situated at the base of the skull in the pituitary gland. The sella turcica is either filled with cerebrospinal fluid, also known as completely empty sella or half-filled with cerebrospinal fluid, known as partially empty sella. The symptoms of empty sella syndrome are extreme headaches. Headaches can occur due to hypertension or high blood pressure, which is a common condition in empty sella syndrome.

In a few cases, there is extreme pressure on the skull from inside as well as outside, optic disc sweeping caused by papilledema, cerebrospinal rhinorrhea, or cerebrospinal fluid leakage through the nose, and vision loss. The main cause of empty sella syndrome is generally idiopathic hyperprolactinemia. However, other causes are Sheehan syndrome, a rare disorder, surgery on the pituitary area, trauma and injury in the head, cured tumors of the pituitary gland, and radiation therapy.

Hyperprolactinemia Medications

Medications for Hyperprolactinemia are antagonists of dopamine receptors such as Risperidone, thioxanthenes, butyrophenones, metoclopramide, pimozide, phenothiazines, and sulpiride. Dopamine-depleting agents- reserpine and methyldopa. Other medicines include cocaine, opiates, tricyclic antidepressants, estrogens, danazol, antiandrogens, cimetidine, cyproheptadine, and isoniazid.

Can hyperprolactinemia be prevented?

Hyperprolactinemia can be prevented by altering the diet, avoiding excessive stress, heavy weightlifting, and high-intensity activities for some time, increasing vitamin E and vitamin B-6, avoiding tight clothing, and avoiding breast pain. Foods that contain a low level of prolactin are beef, beans, shellfish, and turkey, which usually contain a high amount of zinc. Other foods are salmon, chicken, potatoes, spinach, and bananas. Green tea can help immensely, avoid refined carbs, avoid sugar and abstain from overeating or undereating.

FAQ

References

https://my.clevelandclinic.org/health/diseases/22284-hyperprolactinemia