Elevation of plasma-prolactin by monoamine-oxidase inhibitors

Sociodemographic and clinical characteristics related with hyperprolactinaemia in psychiatric clinical population

BACKGROUND

Hyperprolactinaemia (HyperPRL) induced by psychotropic drugs is a high-prevalence consequence which has repercussions in psychical and mental health in the psychiatric population, so this research had the objective to expand which sociodemographic and clinical features are associated with prolactin (PRL) elevation in patients treated with antidepressant and/or antipsychotic drugs.

METHODS

An observational, cross-sectional, comparative and retrolective study was conducted on 300 patients who received clinical attention in a third level of psychiatric care unit in Mexico during 2017. These patients have been reported to show PRL levels greater than 25 ng/mL among women and greater than 20 ng/mL among men. In the same way, sociodemographic and clinical variables were collected, as well as psychiatric diagnosis and type of psychopharmacological treatment used by the patients.

RESULTS

HyperPRL was more frequent in women (80.7%) than men (19.3%). The mean levels of PRL were 68.94 ± 62.28 ng/mL with higher levels in women (71.9 ± 67.3, p=.02). Regarding the treatment, 78.3%, 71.3% and 49.7% consumed antipsychotics, antidepressants, and both drugs, respectively. The relationship between hyperPRL (>100 n/mL) and typical antipsychotics was dose-dependent (33.23 ± 13.24 mg, p=.01). In the multivariate regression models according to the type of treatment, as well as the demographic and clinical features, hyperPRL was associated independently with the use of antipsychotic treatment, pituitary adenoma and hypertension (R²=0.05).

CONCLUSIONS

HyperPRL is a complex clinical syndrome frequent in the psychiatric population with detrimental long-term consequences, as well as its relationship with the use of psychotropic drugs as in the case of antipsychotics. Effective actions should be implemented in the prevention, approach and treatment of this condition paying special attention to the accompanying medical comorbidities.

Antidepressant-induced hyperprolactinaemia: incidence, mechanisms and management

Prolactin, a polypeptide hormone, is responsible, amongst other things, for milk production during lactation and breast enlargement during pregnancy. Numerous drugs can affect prolactin levels. Most commonly, conventional antipsychotics are associated with hyperprolactinaemia but there have also been reports of antidepressants causing hyperprolactinaemia. This review sets out to establish the incidence of antidepressant-induced hyperprolactinaemia, its possible mechanism and to determine appropriate remedial actions. Nearly all antidepressants are reported to be associated with hyperprolactinaemia. Incidence rates were not clearly established and symptoms were very rare. The mechanism by which antidepressants may cause hyperprolactinaemia is not fully understood, though several theories have been postulated, such as serotonin stimulation of GABAergic neurons and indirect modulation of prolactin release by serotonin. Patients taking antidepressants presenting to their clinician with symptoms potentially related to hyperprolactinaemia, such as galactorrhoea, should have their plasma prolactin level measured and their antidepressant changed if an increased prolactin level is confirmed. Routine monitoring of prolactin levels is otherwise not appropriate.

Hyperprolactinemia associated with psychotropics--a review

INTRODUCTION

Different classes of psychotropics can cause hyperprolactinemia to varying degrees. Among antipsychotics, typical agents and risperidone are the most frequent and significant offenders. In this review we discuss the pathophysiology, offending medications, assessment and management of hyperprolactinemia.

METHODS

We did a literature review between 1976 and 2008 using PubMed, MEDLINE, PsychINFO and Cochrane database. Search terms used were prolactin, hyperprolactinemia, psychotropics, antipsychotics, typical antipsychotics, atypical antipsychotics, antidepressants and SSRIs.

RESULTS

Prolactin elevation is more common with antipsychotics than with other classes of drugs. Typical antipsychotics are more prone to cause hyperprolactinemia than atypical agents. Management options include discontinuation of offending medication, switching to another psychotropic, supplementing concurrent hormonal deficiencies and adding a dopamine agonist or aripiprazole.

CONCLUSION

Clinicians need to be alert about the potential for hyperprolactinemia and its manifestations with these medications. Prolactin levels need to be monitored and other causes of hyperprolactinemia ruled out in suspected cases.

Drugs and prolactin

Medications commonly cause hyperprolactinemia and their use must be differentiated from pathologic causes. The most common medications to cause hyperprolactinemia are the antipsychotic agents, although some of the newer atypical antipsychotics do not do so. Other medications causing hyperprolactinemia include antidepressants, antihypertensive agents, and drugs which increase bowel motility. Often, the medication-induced hyperprolactinemia is symptomatic, causing galactorrhea, menstrual disturbance, and erectile dysfunction. In the individual patient, it is important differentiate hyperprolactinemia due to a medication from a structural lesion in the hypothalamic-pituitary area. This can be done by stopping the medication temporarily to determine if the prolactin (PRL) levels return to normal, switching to another medication in the same class which does not cause hyperprolactinemia (in consultation with the patient's physician and/or psychiatrist), or by performing an MRI or CT scan. If the hyperprolactinemia is symptomatic, management strategies include switching to an alternative medication which does not cause hyperprolactinemia, using estrogen/testosterone replacement, or cautiously adding a dopamine agonist.

Medication-induced 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.

Medical management of prolactin-secreting pituitary adenomas

Prolactinomas are a common cause of reproductive/sexual dysfunction. Once other causes of hyperprolactinemia have been excluded with a careful history and physical examination, routine chemistries, a pregnancy test and a TSH, imaging with MRI or CT will delineate the size and extent of the tumor. Medical therapy is the initial treatment of choice. When infertility is the primary indication for treatment, bromocriptine use has an extensive safety experience and is preferred. However, for other indications, cabergoline appears to be more efficacious and better tolerated. Transsphenoidal surgery remains an option, especially for patients with microadenomas, when medical therapy is ineffective.

Disorders of prolactin secretion

Prolactinomas are a common cause of reproductive/sexual dysfunction. Once other causes of hyperprolactinemia have been excluded with a careful history and physical examination, routine chemistries, and an assay for TSH, MR imaging, or CT will delineate the size and extent of the tumor. Medical therapy is the initial treatment of choice. When infertility is the primary indication for treatment, bromocriptine use has an extensive safety record and is preferred. For other indications, cabergoline seems to be more efficacious and better tolerated. Transsphenoidal surgery remains an option, especially for patients with microadenomas, when medical therapy is ineffective.

Medical treatment of prolactinomas

Prolactinomas are a common cause of reproductive and sexual dysfunction. Once other causes of hyperprolactinemia have been excluded with a careful history, physical examination, routine chemistries, and a TSH, MR imaging or computerized tomography will delineate the size and extent of the tumor. Medical therapy is the initial treatment of choice. When infertility is the primary indication for treatment, bromocriptine use has an extensive safety experience and is preferred. For other indications, however, cabergoline appears to be more efficacious and better tolerated. Transsphenoidal surgery remains an option, especially for patients with microadenomas, when medical therapy is ineffective.

Inhibition of monoamine oxidase by moclobemide: effects on monoamine metabolism and secretion of anterior pituitary hormones and cortisol in healthy volunteers

1. Single oral doses (100, 200 and 300 mg) of moclobemide, a reversible inhibitor of monoamine oxidase (MAO) with predominant effects on the A-type of the enzyme, were administered to eight young, healthy male volunteers in a double-blind, random-order, placebo-controlled study. The investigation was thereafter continued in an open fashion by administering a single 10 mg dose of the MAO-B inhibitor deprenyl to the same subjects. 2. Deamination of catecholamines was powerfully and dose-dependently inhibited by moclobemide, as evidenced by up to 40% decreases in the urinary excretion of deaminated catecholamine metabolites, corresponding increases in the excretion of non-deaminated, methylated metabolites, and up to 79% average decreases in the plasma concentration of 3,4-dihydroxyphenylglycol (DHPG), a deaminated metabolite of noradrenaline (NA), and up to 75% average decreases in the plasma concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC), a deaminated metabolite of dopamine. The urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA) was only slightly reduced. In contrast, deprenyl, in a dose which almost totally inhibited MAO-B activity in blood platelets, did not appreciably affect the plasma concentrations of DHPG or DOPAC. 3. Due to the rapid, reversible, dose-dependent and MAO-A specific effect of moclobemide on plasma concentrations of DHPG, it is suggested that DHPG in plasma may be a useful indicator of the magnitude and duration of MAO-A inhibition in man. 4. Sympatho-adrenal function at rest was not significantly altered by moclobemide, as judged by unchanged plasma catecholamine concentrations and stable blood pressure and heart rate recordings. 5. Monoamine oxidase type B activity in blood platelets was slightly (less than 30%) and transiently inhibited after moclobemide. 6. The secretion of prolactin was dose-dependently stimulated by moclobemide, whereas the plasma concentrations of growth hormone (hGH) and cortisol remained unchanged.

Drug-induced changes in prolactin secretion. Clinical implications

Prolactin secretion is affected by various diseases as well as by many drugs in humans and animals. While marked hyperprolactinaemia suggests the presence of a pituitary tumor, moderate changes may also occur in various endocrine or non-endocrine disorders. Drugs can interfere with prolactin regulation via complex mechanisms at the hypothalamus or at the pituitary site, but possible changes in prolactin metabolism are poorly understood as yet. This survey of the literature up to June 1986 covers the influence of various groups of drugs and agents on the plasma prolactin level under various conditions. It contains information that will facilitate evaluation of whether hyper- or hypoprolactinaemia may result from therapeutic intervention or must be related to an underlying disease. It is obvious that more subtle changes can be revealed by the use of dynamic tests either to stimulate or to suppress prolactin secretion.

Effects of tranylcypromine treatment on neuroendocrine, behavioral, and autonomic responses to tryptophan in depressed patients

Effects of intravenous administration of the serotonin precursor tryptophan (TRP) on serum prolactin, neuromotor function, subjective mood, and blood pressure and pulse were determined in nine depressed patients before and during placebo-controlled treatment with the monoamine oxidase inhibitor (MAOI) tranylcypromine. Tranylcypromine significantly increased the prolactin response to TRP. Four patients developed a distinctive neuromotor syndrome following TRP during tranylcypromine, but not placebo, treatment. Symptoms included hyperreflexia, ankle clonus, nystagmus, incoordination, tremor, myoclonic jerks, and nausea. There were no differences in peak prolactin, mood, or autonomic responses between patients with and without the syndrome, but those with the syndrome had received active tranylcypromine for a significantly shorter duration. Tranylcypromine had little effect on TRP-induced changes in mood or autonomic function, except for a modest enhancement of the TRP-induced rise in diastolic blood pressure. These results suggest that tranylcypromine treatment may enhance serotonin function in depression.

Galactorrhea in the adolescent

Inappropriate lactation--that which occurs beyond the usual postpartum or breast-feeding period or in the male--has been of medical interest for centuries. There is a suggestion that the first recorded case occurred in the Bible in the Book of Esther wherein Mordecai may have breast-fed his niece Esther [1,2]. The Talmud describes a man who nursed his infant after his wife's death during childbirth [3]. Lactation in virgin women was noted by the early Greeks [4], and Aristotle observed lactation in men [5]. The phenomenon of "witch's milk," seen in the newborn, was described as early as 1684 by Bonetus [6]. The first alleged pediatric case of nonpuerperal lactation was of an 8-year-old girl who was able to suckle her baby brother as reported in the 18th Century by Baudelocque [7]. Subsequently, many other cases of abnormal lactation were described in the 19th and early 20th centuries [7-10]. In the past 15 years, there has been a vast proliferation of cases and studies concerning galactorrhea of both sexes [11]. The advent of the prolactin radioimmunoassay was the single most important factor behind the profusion of these investigations [11-14]. Most recently, attention has focused on the high incidence of pituitary tumors--specifically the prolactinoma--in women and to some degree in men [13,15]. The occurrence of such tumors in children and adolescents is also receiving more attention [16,17]. The purpose of this review is to update the reader on galactorrhea with a specific emphasis on: 1) outlining the various causes of galactorrhea that may be seen in adolescent patients; 2) describing the work-up and management of both the male and female adolescent patient with galactorrhea; and 3) describing what is known about the natural history of galactorrhea. A brief description of the physiology of the hypothalamic-pituitary-breast axis and lactation is also presented.

Effect of a reversible and selective MAO-A inhibitor (cimoxatone) on diurnal variation in plasma prolactin level in man

Prolactin (PRL) secretion is stimulated by serotonin (5-HT) and inhibited by dopamine (DA). 5-HT is generally recognized as a substrate for type A monoamine oxidase (MAO), whereas DA is considered as a substrate for either A or B, or both forms of MAO, depending on the species and tissues used. The effect of cimoxatone, a reversible, selective MAO-A inhibitor, on diurnal variation in plasma PRL level was investigated in healthy adults after a single 40 mg oral dose, as an indirect approach to investigating whether DA is preferentially a substrate for Type A or B MAO in man. The circadian rhythm in PRL, stress conditions and diet were taken into account in the present study, which was placebo-controlled. There was a slight but significant reduction in circulating PRL in the six subjects, which persisted for at least 9 h after cimoxatone. However, the duration of the decrease in plasma PRL was shorter than the inhibition of MAO-A. The results are not inconsistent with the presence of both forms of MAO in the human hypothalamus and with DA as a substrate for both forms in this region, if it is assumed that the hypothalamic concentrations of the drug during the period 0-9 hours was sufficiently high to inhibit DA deamination by both forms of MAO.