What are the endocrine side effects of methyldopa-induced hyperprolactinemia?
Endocrine side effects, such as amenorrhea or galactorrhea, resulting from methyldopa-induced hyperprolactinemia have been reported. A case of inappropriate secretion of antidiuretic hormone is associated with methyldopa. [ Ref]
What causes hyperprolactinemia?
Most cases of hyperprolactinemia are caused by increased prolactin secretion from the pituitary gland, which also produces many other hormones that travel throughout the body. In women, physical or psychological stress, pregnancy and, interestingly, nipple stimulation have all been found to increase prolactin levels.
What are the endocrine side effects of methyldopa?
Endocrine side effects, such as amenorrhea or galactorrhea, resulting from methyldopa-induced hyperprolactinemia have been reported. A case of inappropriate secretion of antidiuretic hormone is associated with methyldopa.
How does methyldopa interact with other medications?
Methyldopa can potentiate the effects of CNS depressants such as barbiturates, benzodiazepines, opiate agonists, or phenothiazines when administered concomitantly. Benzphetamine: (Major) Benzphetamine can increase both systolic and diastolic blood pressure and may counteract the activity of methyldopa.
See 7 key topics from this page & related content
See 7 key topics from this page & related content
What is the mechanism of action of methyldopa?
Mechanism of Action Alpha-methyldopa is converted to methyl norepinephrine centrally to decrease the adrenergic outflow by alpha-2 agonistic action from the central nervous system, leading to reduced total peripheral resistance and decreased systemic blood pressure.
How does dopamine cause hyperprolactinemia?
Dopamine binds to the dopamine D2 receptors on the surface of the lactotroph, which diminish intracellular cyclic AMP (cAMP), consequently decreasing prolactin secretion. Any factor disrupting the delivery of dopamine to the anterior pituitary or disturbing signal transduction may result in hyperprolactinemia.
What drugs cause hyperprolactinemia?
Antipsychotic drugs, first generation Perphenazine, fluphenazine, flupenthixol, promazine, haloperidol, loxapine, chlorpromazine, sulpiride, pimozide Antipsychotics are the most common cause of drug-induced hyperprolactinemia.
How is hyperprolactinemia caused?
Most cases of hyperprolactinemia are caused by increased prolactin secretion from the pituitary gland, which also produces many other hormones that travel throughout the body. In women, physical or psychological stress, pregnancy and, interestingly, nipple stimulation have all been found to increase prolactin levels.
Does dopamine inhibit or stimulate prolactin?
It is well-known that dopamine constitutively inhibits prolactin (PRL) secretion via the dopamine receptor 2 (DR2D). If dopamine is increased or if dopamine receptors hyperfunction, PRL may be reduced. During the first SCZ episode, low PRL levels are associated with worse symptoms.
How do dopamine agonists work hyperprolactinemia?
Dopamine agonists have a dopamine‐mimetic action on the pituitary gland, leading to an increase in the production of dopamine and directly influencing dopamine receptors, inhibiting the release of prolactin (Fitzgerald 2005).
What is the other name for methyldopa?
Aldomet (methyldopa) is an antihypertensive drug used to treat hypertension (high blood pressure). The brand name Aldomet is discontinued in the U.S. Generic forms may be available.
Which drugs cause galactorrhea?
Medications, such as certain sedatives, antidepressants, antipsychotics and high blood pressure drugs. Opioid use. Herbal supplements, such as fennel, anise or fenugreek seed. Birth control pills.
Can birth control pills cause hyperprolactinemia?
The relative odds developing hyperprolactinemia were 2.64 times greater among women who has used oral contraceptives for more than 1 year and 6.25 times greater if this use started before the age of 25.
What happens when prolactin is high?
Too much prolactin reduces the production of the hormones estrogen and testosterone. Too much prolactin also can prevent the release of an egg during the menstrual cycle (anovulation) in females. In males, too much prolactin also can lead to decreased sperm production. Bone loss (osteoporosis).
Why does hypothyroidism cause hyperprolactinemia?
In patients with hypothyroidism, an increase in prolactin is due to compensatory increase in the discharge of central hypothalamic TRH as a result of low thyroxine [1]. In the few hypothyroid patients who have elevated serum prolactin levels, the values become normal when the hypothyroidism is corrected [2].
How does dopamine affect the pituitary gland?
Dopamine regulates the secretion of pituitary hormones: it inhibits permanently the production of prolactin and blocks the gonadotrophins and the thyroid-stimulating hormone. It stimulates inconstantly the secretion of growth hormone and it does not control corticotropin.
How does dopamine inhibit growth hormone?
Dopamine has bccn demonstrated to inhibit pituitary GH and PRL release in virro, through specific membrane-bound dopaminc receptors of the D2 subtype (I I). Moreover, human newborns receiving dopamine exhibit a blunted PRL response to exogenous thyro- tropin releasing hormone (C.
How does dopamine affect lactation?
Summary of Use during Lactation Intravenous dopamine infusion may decrease milk production. Dopamine is known to reduce serum prolactin in nonnursing women, but no information is available on its effect on milk production in nursing mothers.
What medications affect methyldopa?
This list is not complete. Other drugs may affect methyldopa, including prescription and over-the-counter medicines, vitamins, and herbal products.
What is methyldopa?
Methyldopa lowers blood pressure by decreasing the levels of certain chemicals in your blood. This allows your blood vessels (veins and arteries) to relax (widen).
What should I avoid while taking methyldopa?
Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.
Can you take methyldopa if you have liver disease?
You should not use methyldopa if you have liver disease (especially cirrhosis ), or a history of liver problems caused by taking methyldopa. Do not use methyldopa if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.
Does methyldopa harm a baby?
It is not known whether methyldopa will harm an unborn baby. However, having high blood pressure during pregnancy may cause complications such as diabetes or eclampsia (dangerously high blood pressure that can lead to medical problems in both mother and baby).
Can you take methyldopa with MAO inhibitor?
Do not use methyldopa if you have used a MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.
Can you take methyldopa if you have high blood pressure?
Keep using methyldopa as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medicine for the rest of your life. Methyldopa can affect the results of certain medical tests.
What gland secretes prolactin?
Prolactin is secreted solely by the lactotroph cells of the pituitary gland. As a result, hyperprolactinemia results almost exclusively from diseases that cause hypersecretion of prolactin by lactotroph cells. Some of these causes are physiologic and others pathologic.
What is the normal serum prolactin level during pregnancy?
The upper normal value for serum prolactin in most laboratories is approximately 20 ng/mL (20 mcg/L SI units).
Does fasting affect prolactin?
Food has only a small effect on serum prolactin concentrations; therefore, fasting is usually not necessary when having serum prolactin measured. However, if an initial value is mildly elevated (21 to 40 ng/mL), the measurement should be repeated on a fasting specimen.
Does nipple stimulation increase prolactin levels?
Nipple stimulation and breast exams — Nipple stimulation during breastfeeding increases serum prolactin concentrations, presumably via a neural pathway. The magnitude of the increase is directly proportional to the degree of preexisting lactotroph hyperplasia due to estrogen.
What causes hyperprolactinemia?
Physiological, pathological, or pharmacological conditions can cause hyperprolactinemia. [2][3] Any condition that affects secretion and clearance of prolactin will cause hyperprolactinemia. Physiological hyperprolactinemia is transient and adaptive; whereas, pathological and pharmacological hyperprolactinemia are symptomatic with unwanted long-term consequences.
Why do neuroleptics elevate prolactin?
Drugs like neuroleptics elevate prolactin because of their dopamine receptor antagonist property, and atypical antipsychotics act by antagonizing both secretions of serotonin and dopamine.
What is the most common type of prolactin-secreting tumor?
Hyperprolactinemia occurs in less than 1% of the general population and 5% to 14% of patients presenting with secondary amenorrhea.[9] The most common type is a prolactin-secreting tumor (prolactinoma), accounting for up to 40% of all clinically recognized pituitary adenomas.[10] The mean prevalence of prolactinoma is estimated to be around 30 per 100,000 in women and 10 per 100,000 in men; with peak prevalence in women aged 25 to 34 years.[10] Clinical manifestations in women are more obvious and present earlier than in men.
How successful is micro prolactinomas surgery?
Most patients with micro prolactinomas have good prognosis and normalize prolactin levels with treatment. These patients can be managed with medical therapy for a prolonged period. The success of the pituitary surgery also depends upon the size of the tumor, the serum prolactin level, and the experience of the neurosurgeon. The success rate of pituitary surgery is related inversely to tumor size and prolactin levels.[24] Although micro prolactinoma surgery has a high success rate, the recurrence of hyperprolactinemia is relatively high[25] which is about 17% in patients initially considered cured. In the case of macroprolactinoma, around 50% of the patients are in remission after the surgery. In the case of invasive tumors, complete resection may not be possible, and prolactin normalizes in only 32% of patients with a recurrence rate of about 19%.
What is it called when the amount of prolactin exceeds the upper limit?
When the amount of serum prolactin exceeds the upper limit, we call it hyperprolactinemia . The common causes of hyperprolactinemia can be physiological, pathological, or drug-induced. Patients with hyperprolactinemia may remain asymptomatic or can present with signs and symptoms of hypogonadism and galactorrhea. This activity reviews the cause and presentation of hyperprolactinemia and stresses the importance of the interprofessional team in its management.
How is prolactin secreted?
Prolactin hormone is exclusively synthesized and secreted from lactotrophs of the anterior pituitary gland . The secretion rate of prolactin is about 200 to 536 mcg/day/meter square[1] and the half-life is 25 to 50 minutes. Prolactin is metabolized by the liver (75%) and the kidney (25%). The basal level of prolactin in women averages 13 ng/ml and in men, it averages 5 ng/ml. The upper normal limit of serum prolactin level in most laboratories is 15 to 20 ng/ml. When the amount of serum prolactin exceeds the upper limit, we call it hyperprolactinemia. The common causes of hyperprolactinemia can be physiological, pathological, or drug-induced. Patients with hyperprolactinemia may remain asymptomatic or can present with signs and symptoms of hypogonadism and galactorrhea.
Why does prolactin increase during pregnancy?
During pregnancy, the pituitary gland increases in size, also increasing the size of lactotrophs. The gland may double in size during pregnancy.[4] Serum prolactin increases throughout the pregnancy and reaches a peak at delivery.[5] It is probably because of increased serum estradiol concentration. After delivery, estradiol secretion decreases and the serum prolactin becomes normal with breastfeeding. In pregnancy, serum prolactin usually becomes 10 times normal with a range of 35 to 600 ng/ml at term[5]; prolactin in amniotic fluid is 100 times more compared to levels in maternal and fetal blood. [5]
What are the causes of hyperprolactinemia?
Medication use is a common cause of hyperprolactinemia, and it is important to differentiate this cause from pathologic causes, such as prolactinomas. To ascertain the frequency of this clinical problem and to develop treatment guidelines, the medical literature was searched by using PubMed and the reference lists of other articles dealing with hyperprolactinemia due to specific types of medications. The medications that most commonly cause hyperprolactinemia are antipsychotic agents; however, some newer atypical antipsychotics do not cause this condition. Other classes of medications that cause hyperprolactinemia include antidepressants, antihypertensive agents, and drugs that increase bowel motility. Hyperprolactinemia caused by medications is commonly symptomatic, causing galactorrhea, menstrual disturbance, and impotence. It is important to ensure that hyperprolactinemia in an individual patient is due to medication and not to a structural lesion in the hypothalamic/pituitary area; this can be accomplished by (1) stopping the medication temporarily to determine whether prolactin levels return to normal, (2) switching to a medication that does not cause hyperprolactinemia (in consultation with the patient's psychiatrist for psychoactive medications), or (3) performing magnetic resonance imaging or computed tomography of the hypothalamic/pituitary area. If the patient's hyperprolactinemia is symptomatic, treatment strategies include switching to an alternative medication that does not cause hyperprolactinemia, using estrogen or testosterone replacement, or, rarely, cautiously adding a dopamine agonist.
What medications cause hyperprolactinemia?
Other classes of medications that cause hyperprolactinemia include antidepressants, antihypertensive agents, and drugs that increase bowel motility.
What is the first step in treatment for hyperprolactinemia?
The first step in treatment is to determine whether the patient has symptoms related to the hyperprolactinemia. In a woman with normal, regular menses, if nonbothersome galactorrhea is the only reason to perform the PRL measurement, simple reassurance may be all that is needed. In contrast, if a patient has highly symptomatic hyperprolactinemia that, along with amenorrhea, causes decreased libido, bothersome galactorrhea, impotence, or osteoporosis, then a more active treatment strategy is necessary.
What is galactrhea and hyperprolactinemia associated with?
Galactorrhea and hyperprolactinemia associated with protease inhibitors [letter].
How does the hypothalamus affect prolactin secretion?
Critical to an understanding of the ways in which medications affect prolactin (PRL) secretion is an explanation of the neuroendocrine regulation of PRL secretion. The hypothalamus predominantly influences PRL secretion through 1 or more PRL inhibitory factors that reach the pituitary via the hypothalamic/pituitary portal vessels. Disruption of the pituitary stalk leads to moderately increased PRL secretion and to decreased secretion of the other pituitary hormones. Dopamine is the predominant physiological inhibitory factor; blockade of endogenous dopamine receptors by various drugs, including antipsychotic agents, causes PRL secretion to increase. There are PRL-releasing factors as well. Although thyrotropin-releasing hormone (TRH) causes a rapid release of PRL, numerous different experimental approaches have failed to clarify the physiological role of TRH as a PRL-releasing factor. Vasoactive intestinal peptide has stimulatory effects that are selective for PRL; also, a part of the vasoactive intestinal peptide precursor, a similarly sized peptide known as peptide histidine methionine, exerts PRL-releasing properties in humans. The precise roles of these peptides and other PRL-releasing factors such as TRH are unclear.
Why does hypogonadism occur?
The hypogonadism primarily is due to the hyperprolactinemia causing a decrease in the pulsatile secretion of gonadotropin-releasing hormone by the hypothalamus.
What drugs cause amenorrhea?
Two drugs commonly used to increase gastrointestinal motility and stomach emptying in patients with gastroparesis diabeticorum, metoclopramide and domperidone, are dopamine receptor blockers. These drugs cause hyperprolactinemia in more than 50% of patients and commonly cause symptoms of amenorrhea and galactorrhea in women and impotence in men.
What causes hyperprolactinemia?
Most cases of hyperprolactinemia are caused by increased prolactin secretion from the pituitary gland, which also produces many other hormones that travel throughout the body. In women, physical or psychological stress, pregnancy and, interestingly, nipple stimulation have all been found to increase prolactin levels.
How is hyperprolactinemia diagnosed?
Hyperprolactinemia is usually diagnosed based on the patient’s symptoms and history, as well as a physical exam. Blood tests are ordered to detect the levels of prolactin in the blood.
What stands out about Yale Medicine’s approach to hyperprolactinemia?
Yale Medicine physicians are knowledgeable in all realms of reproductive endocrinology, including disorders of prolactin secretion. We understand how various hormones work together to form a complex functional reproductive unit and that each patient presents a unique clinical scenario.
