top of page
Search

Pituitary Galactorrea

  • Writer: Mayta
    Mayta
  • Jan 18, 2024
  • 1 min read

Drug-Induced Galactorrhea

  • Definition: Galactorrhea is the production of breast milk in men or in women who are not breastfeeding. Drug-induced galactorrhea occurs when certain medications lead to an increase in prolactin levels, causing milk secretion.

  • Mechanism: These drugs typically interfere with dopamine action, which normally inhibits prolactin secretion. Without this inhibition, prolactin levels rise, potentially leading to galactorrhea.

Common Medications Causing Galactorrhea

  1. Antipsychotics: Medications like risperidone and haloperidol can increase prolactin levels.

  2. Antidepressants: Especially SSRIs and tricyclics.

  3. Anti-hypertensives: Such as verapamil and methyldopa.

  4. Gastrointestinal drugs: Like metoclopramide, a dopamine antagonist used for nausea.

Drug-Induced Galactorrhea: Mechanisms and Associated Drugs

Dopamine-Receptor Blockade

  • Metoclopramide: A dopamine receptor antagonist that is commonly used for gastrointestinal issues, which can increase prolactin levels.

  • Phenothiazines: A class of antipsychotic drugs that can cause hyperprolactinemia by blocking dopamine receptors.

  • Risperidone: An antipsychotic medication that can increase prolactin levels by antagonizing dopamine receptors.

  • SSRIs (e.g., Fluoxetine, Sertraline): While SSRIs primarily increase serotonin levels, they can also influence dopamine systems and lead to elevated prolactin levels.

  • Tricyclic Antidepressants: These can increase prolactin levels by antagonizing dopamine receptors.

Dopamine-Depleting Agents

  • Reserpine: Used to treat hypertension and some psychotic conditions by depleting dopamine stores.

  • Methyldopa: An antihypertensive medication that can deplete dopamine and elevate prolactin levels.

Inhibition of Dopamine Release

  • Heroin: An opioid that can inhibit dopamine release, potentially leading to increased prolactin levels.

  • Morphine: Another opioid that can inhibit the release of dopamine and cause elevated prolactin.

Histamine-Receptor Blockade

  • Cimetidine: A histamine H2-receptor antagonist that can cause an increase in prolactin levels, potentially leading to galactorrhea.

Stimulation of Lactotrophs

  • Oral Contraceptives: Contain estrogen which can stimulate lactotroph cells in the pituitary gland, increasing the production of prolactin.

  • Verapamil: A calcium channel blocker used to treat hypertension, which can also stimulate prolactin release, although the mechanism may be multifaceted.

Management

For the management of drug-induced galactorrhea, the slide suggests stopping the implicated medication for 3 days, if medically safe to do so, to observe for a decrease in symptoms.



Prolactinoma

  • Definition: A prolactinoma is a benign tumor of the pituitary gland that produces an excessive amount of prolactin.

  • Diagnosis:

  • Exclude other causes of hyperprolactinemia.

  • Serum prolactin levels: Levels >200 ng/ml suggest a prolactinoma (excluding drugs like risperidone and metoclopramide). Levels >500 ng/ml indicate a macroprolactinoma.


Case Secondary amenorrhea

Thyroid Function Tests (TFTs):

  • Regulation of Menstrual Cycle:

  • The menstrual cycle is regulated by a complex interplay of hormones, including those produced by the thyroid gland.

  • Thyroid hormones interact with reproductive hormones. For instance, thyroxine (T4) and triiodothyronine (T3) can influence the levels of sex hormone-binding globulin (SHBG), affecting the availability of estrogen and other sex hormones.

  • Impact on Ovulation:

  • Normal thyroid function is essential for ovulation. Both excess and insufficient thyroid hormones can disrupt the hypothalamic-pituitary-ovarian axis.

  • In hypothyroidism, elevated Thyroid Stimulating Hormone (TSH) levels can lead to increased prolactin, interfering with the release of FSH and LH, which are critical for follicle development and ovulation.

  • Hyperthyroidism may cause menstrual irregularities by speeding up the body's overall metabolism, which can disrupt the menstrual cycle's regular rhythm.

  • Clinical Implications:

  • It's not just the presence of menstrual irregularities but also their pattern that can hint at thyroid involvement. For example, menorrhagia (heavy menstrual bleeding) is more common in hypothyroidism.

Renal Function Tests:

Prolactin Level:




Recent Posts

See All

Comments

Rated 0 out of 5 stars.
No ratings yet
Add a rating
Post: Blog2_Post

Message for International Readers
Understanding My Medical Context in Thailand

By Uniqcret, M.D.
 

Dear readers,
 

My name is Uniqcret, which is my pen name used in all my medical writings. I am a Doctor of Medicine trained and currently practicing in Thailand, a developing country in Southeast Asia.
 

The medical training environment in Thailand is vastly different from that of Western countries. Our education system heavily emphasizes rote memorization—those who excel are often seen as "walking encyclopedias." Unfortunately, those who question, critically analyze, or solve problems efficiently may sometimes be overlooked, despite having exceptional clinical thinking skills.
 

One key difference is in patient access. In Thailand, patients can walk directly into tertiary care centers without going through a referral system or primary care gatekeeping. This creates an intense clinical workload for doctors and trainees alike. From the age of 20, I was already seeing real patients, performing procedures, and assisting in operations—not in simulations, but in live clinical situations. Long work hours, sometimes exceeding 48 hours without sleep, are considered normal for young doctors here.
 

Many of the insights I share are based on first-hand experiences, feedback from attending physicians, and real clinical practice. In our culture, teaching often involves intense feedback—what we call "โดนซอย" (being sliced). While this may seem harsh, it pushes us to grow stronger, think faster, and become more capable under pressure. You could say our motto is “no pain, no gain.”
 

Please be aware that while my articles may contain clinically accurate insights, they are not always suitable as direct references for academic papers, as some content is generated through AI support based on my knowledge and clinical exposure. If you wish to use the content for academic or clinical reference, I strongly recommend cross-verifying it with high-quality sources or databases. You may even copy sections of my articles into AI tools or search engines to find original sources for further reading.
 

I believe that my knowledge—built from real clinical experience in a high-intensity, under-resourced healthcare system—can offer valuable perspectives that are hard to find in textbooks. Whether you're a student, clinician, or educator, I hope my content adds insight and value to your journey.
 

With respect and solidarity,

Uniqcret, M.D.

Physician | Educator | Writer
Thailand

bottom of page