Drug-induced hypo- and hyperprolactinemia: mechanisms, clinical and therapeutic consequences

Exploring the potential pharmacological mechanism of aripiprazole against hyperprolactinemia based on network pharmacology and molecular docking

The current primary therapeutic approach for schizophrenia is antipsychotic medication, and antipsychotic-induced hyperprolactinemia occurs in 40-80% of patients with schizophrenia. Aripiprazole, an atypical antipsychotic belonging to the quinolinone derivative class, can reduce the likelihood of developing hyperprolactinemia, but the pharmacological mechanisms of this reduction are unknown. This study aimed to explore the molecular mechanism of action of aripiprazole in treating hyperprolactinemia based on network pharmacology and molecular docking techniques. This study identified a total of 151 potential targets for aripiprazole from the DrugBank, TCMSP, BATMAN-TCM, TargetNet, and SwissTargetPrediction databases. Additionally, 71 hyperprolactinemia targets were obtained from the PharmGKB, DrugBank, TTD, GeneCards, OMIM, and DisGENET databases. Utilizing Venny 2.1.0 software, an intersection of 27 genes was identified between aripiprazole and hyperprolactinemia. To construct a common target protein-protein interaction (PPI) network, the common targets obtained from both sources were input into the STRING database. The resulting PPI network was then imported into Cytoscape 3.7.2 software, which identified eight core targets associated with aripiprazole's treatment of hyperprolactinemia. Subsequently, a PPI network was established for these targets. Enrichment analysis of the key targets was conducted using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes in the DAVID database. Additionally, molecular docking verification of the interaction between aripiprazole and the core targets was performed using AutoDock Vina software. Aripiprazole's intervention in hyperprolactinemia primarily targets the following core proteins: Solute Carrier Family 6 Member 3 (SLC6A3), monoamine oxidase (MAO-B), Dopamine D2 receptor (DRD2), 5-hydroxytryptamine (serotonin) receptor 2A (HTR2A), 5-hydroxytryptamine (serotonin) receptor 2C (HTR2C), cytochrome P450 2D6 (CYP2D6), Dopamine D1 receptor (DRD1), Dopamine D4 receptor (DRD4). These targets are predominantly involved in biological processes such as the adenylate cyclase-activating adrenergic receptor signaling pathway, G-protein coupled receptor signaling pathway coupled to cyclic nucleotide second messenger, phospholipase C-activating G-protein coupled receptor signaling pathway, chemical synaptic transmission, and response to xenobiotic stimulus. Primary enrichment occurs in signaling pathways such as the neuroactive ligand-receptor interaction and serotonergic synapse pathways. Molecular docking results demonstrate a favorable affinity between aripiprazole and the core target proteins MAO-B, DRD2, SLC6A3, HTR2C, HTR2A, CYP2D6, DRD4, and DRD1. Network pharmacology predicted potential targets and signaling pathways for aripiprazole's intervention in hyperprolactinemia, offering theoretical support and a reference basis for optimizing clinical strategies and drug development involving aripiprazole.

A Century of Prolactin: Emerging Perspectives as a Metabolic Regulator

Prolactin, a hormone that has been studied for almost a century, has evolved from a reproductive regulator to a key player in metabolic health. Initially identified for its lactogenic role, the impact of prolactin on glucose and lipid metabolism became evident in the 1970s, leading to a paradigm shift in our understanding. Deviations in prolactin levels, including hyperprolactinaemia and hypoprolactinaemia, have been associated with adverse effects on glucose and lipid metabolism. Mechanistically, prolactin regulates metabolic homoeostasis by maintaining islet abundance, regulating the hypothalamic energy regulatory centre, balancing adipose tissue expansion, and regulating hepatic metabolism. Given the widespread use of pharmaceutical agents that affect prolactin levels, it is important to examine prolactin-related metabolic effects. Recently, a profound exploration of the intricate metabolic role of prolactin has been conducted, encompassing its rhythm-dependent regulatory influence on metabolism and its correlation with cognitive impairment associated with metabolic diseases. In this review, we highlight the role of prolactin as a metabolic regulator, summarise its metabolic effects, and discuss topics related to the association between prolactin and metabolic comorbidities.

Pharmacological and non-pharmacological interventions for irritability in autism spectrum disorder: a systematic review and meta-analysis with the GRADE assessment

BACKGROUND

Numerous interventions for irritability in autism spectrum disorder (ASD) have been investigated. We aimed to appraise the magnitude of pharmacological and non-pharmacological interventions for irritability in ASD without any restrictions in terms of eligible interventions.

METHODS

We systematically searched PubMed/MEDLINE, Scopus, and Web of Science until April 15, 2023. We included randomized controlled trials (RCTs) with a parallel design that examined the efficacy of interventions for the treatment of irritability in patients of any age with ASD without any restrictions in terms of eligible interventions. We performed a random-effects meta-analysis by pooling effect sizes as Hedges' g. We classified assessed interventions as follows: pharmacological monotherapy, risperidone plus adjuvant therapy versus risperidone monotherapy, non-pharmacological intervention, and dietary intervention. We utilized the Cochrane tool to evaluate the risk of bias in each study and the GRADE approach to assess the certainty of evidence for each meta-analyzed intervention.

RESULTS

Out of 5640 references, we identified 60 eligible articles with 45 different kinds of interventions, including 3531 participants, of which 80.9% were males (mean age [SD] = 8.79 [3.85]). For pharmacological monotherapy, risperidone (Hedges' g - 0.857, 95% CI - 1.263 to - 0.451, certainty of evidence: high) and aripiprazole (Hedges' g - 0.559, 95% CI - 0.767 to - 0.351, certainty of evidence: high) outperformed placebo. Among the non-pharmacological interventions, parent training (Hedges' g - 0.893, 95% CI - 1.184 to - 0.602, certainty of evidence: moderate) showed a significant result. None of the meta-analyzed interventions yielded significant effects among risperidone + adjuvant therapy and dietary supplementation. However, several novel molecules in augmentation to risperidone outperformed risperidone monotherapy, yet from one RCT each.

LIMITATIONS

First, various tools have been utilized to measure the irritability in ASD, which may contribute to the heterogeneity of the outcomes. Second, meta-analyses for each intervention included only a small number of studies and participants.

CONCLUSIONS

Only risperidone, aripiprazole among pharmacological interventions, and parent training among non-pharmacological interventions can be recommended for irritability in ASD. As an augmentation to risperidone, several novel treatments show promising effects, but further RCTs are needed to replicate findings. Trial registration PROSPERO, CRD42021243965.

The association of hypogonadism with depression and its treatments

According to World Health Organization estimates, 5% of the adult population worldwide suffers from depression. In addition to the affective, psychomotor and cognitive symptoms which characterize this mood disorder, sexual dysfunction has been frequently reported among men suffering from depression. The most common sexual manifestations are decreased libido, erectile dysfunction and orgasmic disorder. In addition, epidemiological studies have documented a reduction of testosterone concentrations in men with depression and, for these reasons, depressive disorders appear as one possible cause of male functional hypogonadism. Moreover, some largely used antidepressant medications can cause or worsen sexual complaints, thus depression and its treatments rise several andrological-relevant issues. The other way round, men with hypogonadism can manifest depressed mood, anxiety, insomnia, memory impairment which, if mild, may respond to testosterone replacement therapy (TRT). However, the prevalence of functional hypogonadism in depression, and of depressive symptoms in hypogonadal men, is not known. Severe depressive symptoms do not respond to TRT, while the effect of treating major depression on functional hypogonadism, has not been investigated. Overall, the clinical relevance of each condition to the other, as well as the physiopathological underpinnings of their relationship, are still to be clarified. The present review summarizes current evidence on the influence of testosterone on mood and of depression on the hypothalamic-pituitary-testis axis; the clinical association between male hypogonadism and depression; and the reciprocal effects of respective treatments.

Risperidone ameliorated 1,2-Diacetylbenzene-induced cognitive impairments in mice via activating prolactin signaling pathways

Cognitive impairment and organic solvent exposure have been becoming public health concerns due to an increasingly aging population, increased life expectancy, urbanization, and industrialization. Converging evidence indicates the link between 1,2-diacetylbenzene (DAB), prolactin (PRL), risperidone, and cognitive impairment. However, these relationships remain unclear. We investigated the therapeutic properties of risperidone in DAB-induced cognitive impairment using both in vivo and in silico methods. Risperidone alleviated DAB-induced cognitive impairment in hippocampal mice, possibly by inhibiting GSK-3β, β-amyloid, CDK5, BACE, and tau hyperphosphorylation. Risperidone also attenuated the activation of TREM-1/DAP12/NLRP3/caspase-1/IL-1β, and TLR4/NF-κB pathways caused by DAB. Furthermore, risperidone inhibited DAB-induced oxidative stress, advanced glycation end products, and proinflammatory cytokines, as well as increased the expression of Nrf2, IL-10, Stat3, MDM2, and catalase activity. On the other hand, risperidone activated the expression of IRS1, PI3K, AKT, BDNF, Drd2, Scna5, and Trt as well as reduced the Bax/Bcl2 ratio and Caspase-3 levels. In silico analyses identified the prolactin signaling pathway, miR-155-5p, miR-34a-5p, and CEBPB as the main molecular mechanisms involved in the pathophysiology of DAB-induced cognitive impairment and targeted by risperidone. Our results suggest that risperidone could be used to treat cognitive impairment caused by organic solvents, especially DAB.

Peony-Glycyrrhiza Decoction for Antipsychotic-Related Hyperprolactinemia in Patients with Schizophrenia: A Randomized Controlled Trial

Background

Most antipsychotic drugs are dopamine receptor antagonists that usually lead to abnormal increases in prolactin concentrations and the development of hyperprolactinemia (HPRL), which in turn causes sexual dysfunction in patients. Peony-Glycyrrhiza Decoction (PGD) enhanced dopamine D2 receptors (DRD2) and dopamine transporter (DAT) and significantly reversed the expression of DRD2 and DAT. Therefore, we hypothesized that PGD might effectively improve hyperprolactinemia and alleviate sexual dysfunction in patients.

Methods

We performed an 8-week randomized controlled study on 62 subjects with schizophrenia who were randomized into two groups. The experimental group was treated with the PGD intervention, and the control group did not receive treatment. The primary outcome indicators were the levels of sex hormones and the total Arizona Sexual Experience Scale (ASEX) score.

Results

There was a significant difference in PRL levels between the two groups at weeks 4 and 8. From the beginning to the end of the experiment, there was a significant increase in PRL levels in the control group, while there was no significant change in the experimental group. The ASEX scale assessed sexual function in both groups, and patients in the experimental group showed an improvement in sexual function at week 8. During the experiment, the two groups found no differences between Positive and Negative Syndrome Scale (PANSS) scores and Treatment Emergent Symptom Scale (TESS) scores.

Conclusion

PGD significantly improved the patient's sexual function but was less effective in reducing prolactin levels and may prevent further increases in prolactin levels.

In silico identification of the potential molecular mechanisms involved in protective effects of prolactin on motor and memory deficits induced by 1,2-Diacetylbenzene in young and old rats

We aimed to identify the molecular mechanisms through which prolactin protects against 1,2-Diacetylbenzene (DAB)-induced memory and motor impairments. The gene expression omnibus database (no. GSE119435), transcriptomic data, GeneMANIA, ToppGeneSuite, Metascape, STRING database, Cytoscape, and Autodock were used as the core tools in in-silico analyses. We observed that prolactin may improve memory and motor deficits caused by DAB via 13 genes (Scn5a, Lmntd1, LOC100360619, Rgs9, Srpk3, Syndig1l, Gpr88, Egr2, Ctxn3, Drd2, Ttr, Gpr6, and Ecel1) in young rats and 9 genes (Scn5a, Chat, RGD1560608, Ucma, Lrrc31, Gpr88, Col1a2, Cnbd1, and Ttr) in old rats. Almost all of these genes were downregulated in both young and old rats given DAB, but they were increased in both young and old rats given prolactin. Co-expression interactions were identified as the most important interactions (83.2 % for young rats and 100 % for old rats). The most important mechanisms associated with prolactin's ability to counteract DAB were identified, including "learning and memory," and "positive regulation of ion transport" in young rats, as well as "acetylcholine related pathways," "inflammatory response pathway," and "neurotransmitter release cycle" in old rats. We also identified several key miRNAs associated with memory and motor deficits, as well as prolactin and DAB exposure (rno-miR-141-3p, rno-miR-200a-3p, rno-miR-124-3p, rno-miR-26, and rno-let-7 families). The most significant transcription factors associated with differentially expressed gene regulation were Six3, Rxrg, Nkx26, and Tbx20. These findings will contribute to our understanding of the processes through which prolactin's beneficial effects counteract DAB-induced memory and motor deficits.

Characteristics of adverse reactions among antipsychotic drugs using the Korean Adverse Event Reporting System database from 2010 to 2019

BACKGROUND

Retrospective studies using spontaneous reporting system databases have provided a great understanding of adverse drug reactions (ADRs) in the real world, complementing the data obtained from randomized controlled trials. However, there have been few reports on large-scale epidemiological studies on the adverse effects of antipsychotics in Asia.

AIM

This study aimed to investigate the characteristics of antipsychotic ADRs using a nationwide pharmacovigilance database.

METHODS

Data were collected from the Korea Adverse Event Reporting System database between 2010 and 2019. The study subjects were selected using the International Classification of Disease codes for diseases related to psychosis and Electronic Data Interchange codes for amisulpride, aripiprazole, clozapine, haloperidol, olanzapine, paliperidone, quetiapine, risperidone, and ziprasidone. The causality assessment of "possible," "probable," or "certain" by the World Health Organization-Uppsala Monitoring Center System causality category was selected. All data were descriptively analyzed.

RESULTS

In total, 5067 adverse events associated with antipsychotic drugs were reported. The antipsychotics that commonly resulted in ADRs were quetiapine (47.7%), olanzapine (11.3%), and clozapine (10.7%). Serious ADRs were most commonly observed with clozapine. Gastrointestinal and central nervous system problems occurred within a month when ADRs were classified according to the time of onset. In contrast, metabolic and bone marrow-related symptoms occurred after long-term use. Sedation and nausea were the most common ADRs in children and adolescents, whereas constipation and dizziness were common in adults and the elderly.

CONCLUSIONS

This study extends our knowledge of antipsychotic ADRs in the Asian population.

Metformin in the Treatment of Amisulpride-Induced Hyperprolactinemia: A Clinical Trial

Objective

To evaluate the efficacy and safety of metformin in the treatment of amisulpride-induced hyperprolactinemia.

Methods

A total of 86 schizophrenic patients who developed hyperprolactinemia after taking amisulpride were screened and randomly assigned to the metformin group (42 patients) and placebo group (44 patients) and followed up for eight weeks. The patients’ serum prolactin levels, blood glucose and lipids were measured at the baseline and the end of the intervention. The treatment emergent symptom scale (TESS) was also assessed.

Results

After eight weeks of intervention, serum prolactin levels in the metformin group decreased from (1737.360 ± 626.918) mIU/L at baseline to (1618.625 ± 640.865) mIU/L, whereas serum prolactin levels in the placebo group increased from (2676.470 ± 1269.234) mIU/L at baseline to (2860.933 ± 1317.376) mIU/L. There was a significant difference in prolactin changes (F^covariance = 9.982, P = 0.002) between the two groups. There was no significant difference in the incidence of adverse drug reactions (P > 0.05) between the two groups.

Conclusion

Metformin is able to improve amisulpride-induced hyperprolactinemia with its safety.

Proton pump inhibitors therapy and risk of hyperprolactinemia with associated sexual disorders

Proton pump inhibitors (PPIs) are the most widely prescribed medications in the world. According to numerous studies, PPIs have been linked to hyperprolactinemia, which can lead to a variety of sexual and reproductive issues. This review summarizes the effects of numerous PPIs on the blood prolactin levels and associated sexual dysfunctions, which have an effect on the patient's life quality and fertility. The study is taken into account all the available resources till January 31, 2021. Out of total 364, only 27 relevant resources were involved in this review. In certain studies, short-term PPIs use has been shown to have little or no effect on the blood prolactin and other reproductive hormones levels. PPIs have been linked to the development of hyperprolactinemia in several case studies with varying degrees of the blood prolactin levels increase seen in individuals taking PPI alone or in combination with medications, like prokinetics. The relative risk of the sexual consequences development, such as gynecomastia, has been documented using lansoprazole and omeprazole in various cohort studies. On the other hand, other bits of data are insufficient to establish a definite relationship that can turn a possibility into certainty. The majority of the literature data is comprising of double-blind, randomized, crossover studies, case reports, and adverse drug reaction incidents reported to various pharmacovigilance centers. To investigate this link, high-quality studies in patients taking PPIs for a longer time period are needed. We conclude this article with a comprehensive discussion of the hyperprolactinemia clinical implications and the PPIs' function.

Occurrence of macroprolactinemia in schizophrenia patients treated with risperidone or amisulpride

OBJECTIVE

To investigate macroprolactinemia caused by antipsychotics and its clinical significance.

METHODS

A total of 133 patients with schizophrenia were selected, all of whom were treated with either risperidone or amisulpride alone. The levels of total prolactin (T-PRL) and macroprolactin (MPRL) were measured before treatment as well as the second, fourth, and sixth weeks of treatment.

RESULTS

After 2 weeks of treatment, 75.09% (100/133) of the patients met the diagnostic criteria for hyperprolactinemia, the incidence of macroprolactinemia was 43% (43/100), and MPRL levels were positively correlated T-PRL levels.

CONCLUSION

Risperidone and amisulpride caused hyperprolactinemia and macroprolactinemia; thus, detection of MPRL in the clinical setting should be performed as this phenomenon appears early in treatment (the second week) and continues, that can avoid unnecessary examination and treatment for asymptomatic patients with macroprolactinemia.

Integrating machine learning with electronic health record data to facilitate detection of prolactin level and pharmacovigilance signals in olanzapine-treated patients

BACKGROUND AND AIM

Available evidence suggests elevated serum prolactin (PRL) levels in olanzapine (OLZ)-treated patients with schizophrenia. However, machine learning (ML)-based comprehensive evaluations of the influence of pathophysiological and pharmacological factors on PRL levels in OLZ-treated patients are rare. We aimed to forecast the PRL level in OLZ-treated patients and mine pharmacovigilance information on PRL-related adverse events by integrating ML and electronic health record (EHR) data.

METHODS

Data were extracted from an EHR system to construct an ML dataset in 672×384 matrix format after preprocessing, which was subsequently randomly divided into a derivation cohort for model development and a validation cohort for model validation (8:2). The eXtreme gradient boosting (XGBoost) algorithm was used to build the ML models, the importance of the features and predictive behaviors of which were illustrated by SHapley Additive exPlanations (SHAP)-based analyses. The sequential forward feature selection approach was used to generate the optimal feature subset. The co-administered drugs that might have influenced PRL levels during OLZ treatment as identified by SHAP analyses were then compared with evidence from disproportionality analyses by using OpenVigil FDA.

RESULTS

The 15 features that made the greatest contributions, as ranked by the mean (|SHAP value|), were identified as the optimal feature subset. The features were gender_male, co-administration of risperidone, age, co-administration of aripiprazole, concentration of aripiprazole, concentration of OLZ, progesterone, co-administration of sulpiride, creatine kinase, serum sodium, serum phosphorus, testosterone, platelet distribution width, α-L-fucosidase, and lipoprotein (a). The XGBoost model after feature selection delivered good performance on the validation cohort with a mean absolute error of 0.046, mean squared error of 0.0036, root-mean-squared error of 0.060, and mean relative error of 11%. Risperidone and aripiprazole exhibited the strongest associations with hyperprolactinemia and decreased blood PRL according to the disproportionality analyses, and both were identified as co-administered drugs that influenced PRL levels during OLZ treatment by SHAP analyses.

CONCLUSIONS

Multiple pathophysiological and pharmacological confounders influence PRL levels associated with effective treatment and PRL-related side-effects in OLZ-treated patients. Our study highlights the feasibility of integration of ML and EHR data to facilitate the detection of PRL levels and pharmacovigilance signals in OLZ-treated patients.

Prevalence and risk factors of hyperprolactinemia among patients with various psychiatric diagnoses and medications

OBJECTIVES

Hyperprolactinemia is a common adverse event associated with psychotropic medications (mainly antipsychotics) used in the management of schizophrenia and bipolar disorders. The aim of this study was to estimate the prevalence of hyperprolactinemia in psychiatric patients and to evaluate its association with various psychiatric diagnoses and the use of various psychotropic medications.

METHODS

A cross-sectional observational study was conducted between July 2012 and June 2014. Patients were recruited from a number of hospitals located in the five regions of Saudi Arabia. Hyperprolactinemia was defined as blood prolactin levels >25 ng/mL in females and >20 ng/mL in males, regardless of the presence of symptoms.

RESULTS

A total of 997 patients (553 males and 444 females) were included in the current analysis. The average blood prolactin level was 32.6 ± 44.1 ng/mL, with higher levels among females than males (42.9 ± 61.3 versus 24.4 ± 18.6, p < .001). The prevalence of hyperprolactinemia was 44.3%, with no significant gender difference (41.9% in females versus 46.3% in males, p = .164) but with huge variability according to individual antipsychotic and other psychotropic medications. In the multivariate analysis adjusted for demographic and clinical characteristics, hyperprolactinemia was independently and positively associated with using antipsychotic medications (OR = 2.08, 1.26-3.42, p = .004). Additionally, previous hospitalisation, diabetes and hypothyroidism were positively associated, whereas having primary depressive disorders was negatively associated.

CONCLUSIONS

We report a high prevalence of hyperprolactinemia among a large sample of psychiatric patients in Saudi Arabia, which was linked to the use of antipsychotic medications. Routine measurement of blood prolactin levels for all patients maintained on antipsychotic agents is recommended, regardless of symptoms.

Management of prolactinoma: a survey of endocrinologists in China

Objective To assess the current management of prolactinoma among endocrinologists in China. Methods An online survey of a large sample of endocrinologists was conducted in China. The questionnaire included 21 questions related to controversial issues about the management of prolactinomas. Doctors in the endocrinology department of a university-affiliated hospital or a comprehensive secondary hospital in 12 cities from East, West, South, North and Middle China were surveyed. Results A total of 290 valid questionnaires were collected, and the response rate was 40%. When hyperprolactinemia occurred, 97% of the respondents would test thyroid-stimulating hormone routinely. 22% of the respondents considered that prolactin levels <100 ng/mL exclude the presence of a prolactinoma. Only 9% of the respondents believed that prolactin >250 ng/mL could occur in all the following situations as macroprolactinoma, mircoprolactinoma, macroprolactinemia and drug-induced hyperprolactinemia. Surgery was not recommended by 272 (94%) endocrinologists as the first choice for treating microprolactinomas. 58% and 92% of endocrinologists would start drug treatment for microprolactinomas and macroprolactinomas at diagnosis. 70% and 40% chose to withdraw treatment after 2-3 years of prolactin normalization in microprolactinomas and macroprolactinomas. In case of pregnancy, 57% of the respondents considered bromocriptine as choice for women patients. Drug discontinuation after pregnancy was advocated in 63% and 27% for microprolactinoma and macroprolactinoma. Moreover, 44% of endocrinologists believed that breastfeeding was allowable in both micro- and macroprolactinoma. Conclusion This is the first study to investigate the management of prolactinomas among endocrinologists in China. We found that the current clinical treatment was not uniform. Therefore, it is necessary to strengthen the training of endocrinologists to improve clinical diagnosis and treatment practices.

Controversial issues in the management of hyperprolactinemia and prolactinomas - An overview by the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism

Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are not rare. On the other hand, among patients with macroprolactinomas (MACs), artificially low PRL levels may result from the so-called "hook effect". Patients harboring cystic MACs may also present with a mild PRL elevation. The screening for macroprolactin is mostly indicated for asymptomatic patients and those with apparent idiopathic hyperprolactinemia. Dopamine agonists (DAs) are the treatment of choice for prolactinomas, particularly cabergoline, which is more effective and better tolerated than bromocriptine. After 2 years of successful treatment, DA withdrawal should be considered in all cases of microprolactinomas and in selected cases of MACs. In this publication, the goal of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism (SBEM) is to provide a review of the diagnosis and treatment of hyperprolactinemia and prolactinomas, emphasizing controversial issues regarding these topics. This review is based on data published in the literature and the authors' experience.

Effect of Peony-Glycyrrhiza Decoction on Amisulpride-Induced Hyperprolactinemia in Women with Schizophrenia: A Preliminary Study

Objective

The aim of this study is to observe the effect of Peony-Glycyrrhiza Decoction (PGD) on hyperprolactinemia in women with schizophrenia induced by Amisulpride.

Material and Methods

A total of 41 female schizophrenia patients receiving Amisulpride were randomly divided into placebo (n = 20) and PGD groups (n = 21). Maintaining the original Amisulpride dose, the two groups were given placebo and PGD, respectively. The levels of Prolactin (PRL) and other hormones were measured on the initial day and at weeks 4 and 8 after treatment. Changes of clinical symptoms in patients with hyperprolactinemia were observed. The PANSS scores were recorded to assess the psychotic symptoms.

Results

Compared with placebo group, level of PRL decreased while Progesterone increased remarkably in the PGD group at weeks 4 and 8 (p < 0.01), and level of Estradiol in the PGD group increased significantly at week 8 (p < 0.05). There were no differences in PANSS scores and biochemical indexes between two groups at weeks 4 and 8.

Conclusion

PGD can improve symptoms of hyperprolactinemia and hormone levels in women with schizophrenia caused by Amisulpride, without affecting their mental symptoms and biochemical indexes.

Adjunctive metformin for antipsychotic-related hyperprolactinemia: A meta-analysis of randomized controlled trials

Hyperprolactinemia is a common and severe antipsychotic-induced adverse drug reaction. This meta-analysis of randomized controlled trials systematically examined the efficacy and safety of adjunctive metformin for antipsychotic-related hyperprolactinemia in schizophrenia patients. Two independent investigators searched, extracted, and synthesized data. Weighted mean differences and risk ratios with their 95% confidence intervals were calculated using random effect model. Four randomized controlled trials ( n=509) comparing adjunctive metformin ( n=253) with the control groups ( n=256), lasting 22.7 weeks of treatment, were included in the meta-analysis. The metformin group had significantly lower serum prolactin level at endpoint (four randomized controlled trials, n=501; weighted mean difference: -6.87 ug/L (95% confidence interval: -13.24 to -0.51), p=0.03; I²⁼80%) with "moderate quality" based on the grading of recommendations assessment, development, and evaluation system. In patients with menstrual disturbances, the rate of menstruation resumption was 66.7% in the metformin group and 4.8% in the control group. Adverse drug reactions and all-cause discontinuation (three randomized controlled trials, n=339, risk ratio: 0.76 (95% confidence interval: 0.29, 1.97), p=0.57; I²= 0%) were similar between the two groups. Adjunctive metformin appears to be effective and safe for reducing antipsychotic-induced hyperprolactinemia and prolactin-related symptoms in schizophrenia patients. Higher quality randomized controlled trials with a large sample size are warranted to confirm these findings.

Psychotropics and Male Reproduction

Psychotropic drugs, including antidepressants, antipsychotics, and anticonvulsants, all have negative effects on sexual function and semen quality. These adverse events vary among men and are less pronounced for some medications, allowing their effects to be managed to some extent. Use of specific serotonin reuptake inhibitors (SSRIs) is prevalent in men of reproductive age; and application to treat premature ejaculation increases the number of young men on SSRI therapy. Oxidative damage to sperm can result from prolonged residence in the male reproductive tract. The increase in ejaculatory latency seen with SSRIs likely underlies some of their negative effects on semen quality, including higher sperm DNA fragmentation, seen in all SSRIs evaluated thus far. These medications increase prolactin (PRL) levels in some men, and this is often credited with inhibitory effects on male reproduction; however, testosterone levels are generally normal, reducing the likelihood of direct HPG axis inhibition by PRL. The tricyclic antidepressants have also been shown to increase PRL levels in some studies but not in others. The exception is the tricyclic antidepressant clomipramine, which profoundly increases PRL levels and may depress semen quality. Other antidepressants modulating synaptic levels of serotonin, norepinephrine, and/or dopamine may have toxicity similar to SSRIs, but most have not been evaluated. In limited studies, norepinephrine-dopamine reuptake inhibitors (NDRIs) and serotonin agonist/reuptake inhibitors (SARIs) have had minimal effects on PRL levels and on sexual side effects. Antipsychotic medications increase PRL, decrease testosterone, and increase sexual side effects, including ejaculatory dysfunction. The greatest evidence is for chlorpromazine, haloperidol, reserpine, risperidone, and thioridazine, with less effects seen with aripiprazole and clozapine. Remarkably few studies have looked at antipsychotic effects on semen quality, and this is an important knowledge gap in reproductive pharmacology. Lithium increases PRL and LH levels and decreases testosterone although this is informed by few studies. The anticonvulsants, many used for other indications, generally decrease free or bioavailable testosterone with variable effects on the other reproductive hormones. Valproate, carbamazepine, oxcarbazepine, and levetiracetam decrease semen quality; other anticonvulsants have not been investigated for this adverse reaction. Studies are required evaluating endpoints of pregnancy and offspring health for psychotropic medications.

Current Data on and Clinical Insights into the Treatment of First Episode Nonaffective Psychosis: A Comprehensive Review

Implementing the most suitable treatment strategies and making appropriate clinical decisions about individuals with a first episode of psychosis (FEP) is a complex and crucial task, with relevant impact in illness outcome. Treatment approaches in the early stages should go beyond choosing the right antipsychotic drug and should also address tractable factors influencing the risk of relapse. Effectiveness and likely metabolic and endocrine disturbances differ among second-generation antipsychotics (SGAs) and should guide the choice of the first-line treatment. Clinicians should be aware of the high risk of cardiovascular morbidity and mortality in schizophrenia patients, and therefore monitoring weight and metabolic changes across time is mandatory. Behavioral and counseling interventions might be partly effective in reducing weight gain and metabolic disturbances. Ziprasidone and aripiprazole have been described to be least commonly associated with weight gain or metabolic changes. In addition, some of the SGAs (risperidone, amisulpride, and paliperidone) have been associated with a significant increase of plasma prolactin levels. Overall, in cases of FEP, there should be a clear recommendation of using lower doses of the antipsychotic medication. If no or minimal clinical improvement is found after 2 weeks of treatment, such patients may benefit from a change or augmentation of treatment. Clinicians should provide accurate information to patients and relatives about the high risk of relapse if antipsychotics are discontinued, even if patients have been symptom free and functionally recovered on antipsychotic treatment for a lengthy period of time.

Neuroendocrine Regulation of Anxiety: Beyond the Hypothalamic-Pituitary-Adrenal Axis

The central nervous system regulates and responds to endocrine signals, and this reciprocal relationship determines emotional processing and behavioural anxiety. Although the hypothalamic-pituitary-adrenal (HPA) axis remains the best-characterised system for this relationship, other steroid and peptide hormones are increasingly recognised for their effects on anxiety-like behaviour and reward. The present review examines recent developments related to the role of a number of different hormones in anxiety, including pregnane neurosteroids, gut peptides, neuropeptides and hormonal signals derived from fatty acids. Findings from both basic and clinical studies suggest that these alternative systems may complement or occlude stress-induced changes in anxiety and anxiety-like behaviour. By broadening the scope of mechanisms for depression and anxiety, it may be possible to develop novel strategies to attenuate stress-related psychiatric conditions. The targets for these potential therapies, as discussed in this review, encompass multiple circuits and systems, including those outside of the HPA axis.

Prolactin and macroprolactin levels in psychiatric patients receiving atypical antipsychotics: A preliminary study

The aims of this study were to clarify whether atypical antipsychotics can elevate serum levels of both macroprolactin and prolactin, and whether the macroprolactin levels differ according to the type of atypical antipsychotic being taken. In total, 245 subjects were enrolled consecutively in 6 hospitals. Serum prolactin and macroprolactin levels were measured at a single time point during maintenance antipsychotic monotherapy. The mean total serum prolactin levels including macroprolactin were 11.91, 20.73, 16.41, 50.83, 12.84, and 59.1ng/mL for patients taking aripiprazole, blonanserin, olanzapine, paliperidone, quetiapine, and risperidone, respectively, while those for macroprolactin were 1.71, 3.86, 3.73, 7.28, 2.77, and 8.0ng/mL. The total prolactin and macroprolactin levels were significantly higher among those taking paliperidone and risperidone than among those taking any of the other antipsychotics (p<0.01). Moreover, there was a strong positive correlation between serum levels of prolactin and macroprolactin. Sexual dysfunction was reported in 35.5% (87/245) of the total subjects. However, the total prolactin level did not differ significantly between subjects with and without sexual dysfunction except gynecomastia. These findings suggest that treatment with risperidone and paliperidone can induce hyperprolactinemia and macroprolactinemia in psychiatric patients.

The effect of metformin on prolactin levels in patients with drug-induced hyperprolactinemia

BACKGROUND

In bromocriptine-treated hyperprolactinemic patients with impaired glucose tolerance, metformin was found to reduce plasma levels of prolactin. No previous study has investigated its impact on plasma prolactin in patients with drug-induced hyperprolactinemia.

METHODS

The study included 20 women with antipsychotic-induced hyperprolactinemia and 12 normoprolactinemic women, who, because of coexisting glucose metabolism abnormalities, were treated for 6months with metformin. Hyperprolactinemic patients with prediabetes received moderate doses of metformin (1.7g daily), while hyperprolactinemic and normoprolactinemic patients with type 2 diabetes were treated with high-dose metformin (2.55-3g daily). Fasting plasma glucose levels, the homeostatic model assessment 1 of insulin resistance ratio (HOMA1-IR), glycated hemoglobin, as well as plasma levels of prolactin, thyrotropin, adrenocorticotropic hormone and insulin-like growth factor-1 were assessed at baseline and after 6months of treatment.

RESULTS

Despite reducing plasma glucose, HOMA1-IR, and glycated hemoglobin in all treatment groups, metformin decreased prolactin levels only if given at high doses to patients with elevated prolactin levels. No changes in thyrotropin, adrenocorticotropic hormone, and insulin-like growth factor-1 were observed in any treatment groups.

CONCLUSIONS

The obtained results suggest that the effect of metformin on plasma prolactin depends on its dose and is observed only in patients with elevated levels of this hormone.

Aripiprazole-induced Hyperprolactinemia in a Young Female with Delusional Disorder

Hyperprolactinemia is a common adverse effect of antipsychotic medication. Switching over to aripiprazole or adjunctive aripiprazole has been advocated for optimal management of antipsychotic-induced hyperprolactinemia. Adjunctive treatment with aripiprazole has been shown to normalize prolactin levels without affecting already achieved improvements in psychotic symptoms. However, here, we present the case of a 36 year old female with delusional disorder who developed symptomatic hyperprolactinemia while on aripiprazole treatment. Dopamine acts as a tonic inhibitor of prolactin secretion through the tubero-infundibular dopaminergic system. Aripiprazole being a partial agonist has a lower intrinsic activity at the D2 receptor than dopamine, allowing it to act as both, a functional agonist and antagonist, depending on the surrounding levels of dopamine. Hence, in the absence of a competing D2 antagonist and the presence of dopamine (the natural agonist), aripiprazole could act as a functional antagonist and thus elevate prolactin levels.

Hyperprolactinemia and medications for bipolar disorder: systematic review of a neglected issue in clinical practice

Drug-induced changes in serum prolactin (sPrl) levels constitute a relevant issue due to the potentially severe consequences on physical health of psychiatric patients such as sexual dysfunctions, osteoporosis and Prl-sensitive tumors. Several drugs have been associated to sPrl changes. Only antipsychotics have been extensively studied as sPrl-elevating agents in schizophrenia, but the extent to which bipolar disorder (BD) treatments affect sPrl levels is much less known. The objective of this systematic review is to summarize the evidence of the effects of drugs used in BD on Prl. This review followed the PRISMA statement. The MEDLINE/PubMed/Index Medicus, EMBASE, and Cochrane Library databases were systematically searched for articles in English appearing from any time to May 30, 2014. Twenty-six studies were included. These suggest that treatments for BD are less likely to be associated with Prl elevations, with valproate, quetiapine, lurasidone, mirtazapine, and bupropion reported not to change PRL levels significantly and lithium and aripiprazole to lower them in some studies. Taking into account the effects of the different classes of drugs on Prl may improve the care of BD patients requiring long-term pharmacotherapy. Based on the results of this review, lithium and valproate appear to be safer due to their low potential to elevate sPrL; among antipsychotics, quetiapine, lurasidone and aripiprazole appear to be similarly safe.

Challenges and pitfalls in the diagnosis of hyperprolactinemia

The definition of the etiology of hyperprolactinemia often represents a great challenge and an accurate diagnosis is paramount before treatment. Although prolactin levels > 200-250 ng/mL are highly suggestive of prolactinomas, they can occasionally be found in other conditions. Moreover, as much as 25% of patients with microprolactinomas may present prolactin levels < 100 ng/mL, which are found in most patients with pseudoprolactinomas, drug-induced hyperprolactinemia, or systemic diseases. On the other hand, some conditions may lead to falsely low PRL levels, particularly the so-called hook effect, that is an assay artifact caused by an extremely high level of PRL, and can be confirmed by repeating assay after a 1:100 serum sample dilution. The hook effect must be considered in all patients with large pituitary adenomas and PRL levels within the normal range or only modestly elevated (e.g., < 200 ng/mL). An overlooked hook effect may lead to incorrect diagnosis and unnecessary surgical intervention in patients with prolactinomas. Another important challenge is macroprolactinemia, a common finding that needs to be identified, as it usually requires no treatment. Although most macroprolactinemic patients are asymptomatic, many of them may present galactorrhea or menstrual disorders, as well as neuroradiological abnormalities, due to the concomitance of other diseases. Finally, physicians should be aware that pituitary incidentalomas are found in at least 10% of adult population.

Pharmacogenetics of second-generation antipsychotics

This review considers pharmacogenetics of the so called 'second-generation' antipsychotics. Findings for polymorphisms replicating in more than one study are emphasized and compared and contrasted with larger-scale candidate gene studies and genome-wide association study analyses. Variants in three types of genes are discussed: pharmacokinetic genes associated with drug metabolism and disposition, pharmacodynamic genes encoding drug targets, and pharmacotypic genes impacting disease presentation and subtype. Among pharmacokinetic markers, CYP2D6 metabolizer phenotype has clear clinical significance, as it impacts dosing considerations for aripiprazole, iloperidone and risperidone, and variants of the ABCB1 gene hold promise as biomarkers for dosing for olanzapine and clozapine. Among pharmacodynamic variants, the TaqIA1 allele of the DRD2 gene, the DRD3 (Ser9Gly) polymorphism, and the HTR2C -759C/T polymorphism have emerged as potential biomarkers for response and/or side effects. However, large-scale candidate gene studies and genome-wide association studies indicate that pharmacotypic genes may ultimately prove to be the richest source of biomarkers for response and side effect profiles for second-generation antipsychotics.

Circulating levels of hormones, lipids, and immune mediators in post-traumatic stress disorder - a 3-month follow-up study

A number of peripheral blood analytes have been proposed as potential biomarkers of post-traumatic stress disorder (PTSD). Few studies have investigated whether observed changes in biomarkers persist over time. The aim of this study was to investigate the association of combat-related chronic PTSD with a wide array of putative PTSD biomarkers and to determine reliability of the measurements, i.e., correlations over time. Croatian combat veterans with chronic PTSD (n = 69) and age-matched healthy controls (n = 32), all men, were assessed at two time points separated by 3 months. Serum levels of lipids, cortisol, dehydroepiandrosterone-sulfate (DHEA-S), prolactin, and C-reactive protein were determined. Multiplex assay was used for the simultaneous assessment of 13 analytes in sera: cytokines [interferon-γ, interleukin (IL)-1β, IL-2, IL-4, IL-6, TNF-α], adhesion molecules (sPECAM-1, sICAM-1), chemokines (IL-8 and MIP-1α), sCD40L, nerve growth factor, and leptin. Group differences and changes over time were tested by parametric or non-parametric tests, including repeated measures analysis of covariance. Reliability estimates [intraclass correlation coefficient (ICC) and kappa] were also calculated. Robust associations of PTSD with higher levels of DHEA-S [F(1,75) = 8.14, p = 0.006)] and lower levels of prolactin [F(1,75) = 5.40, p = 0.023] were found. Measurements showed good to excellent reproducibility (DHEA-S, ICC = 0.50; prolactin, ICC = 0.79). Serum lipids did not differ between groups but significant increase of LDL-C after 3 months was observed in the PTSD group (t = 6.87, p < 0.001). IL-8 was lower in the PTSD group (t = 4.37, p < 0.001) but assessments showed poor reproducibility (ICC = -0.08). Stable DHEA-S and prolactin changes highlight their potential to be reliable markers of PTSD. Change in lipid profiles after 3 months suggests that PTSD patients may be more prone to hyperlipidemia. High intra-individual variability in some variables emphasizes the importance of longitudinal studies in investigations of PTSD biomarkers.

The effects of novel and newly approved antipsychotics on serum prolactin levels: a comprehensive review

Since the 1970s, clinicians have increasingly become more familiar with hyperprolactinemia (HPRL) as a common adverse effect of antipsychotic medication, which remains the cornerstone of pharmacological treatment for patients with schizophrenia. Although treatment with second-generation antipsychotics (SGAs) as a group is, compared with use of the first-generation antipsychotics, associated with lower prolactin (PRL) plasma levels, the detailed effects on plasma PRL levels for each of these compounds in reports often remain incomplete or inaccurate. Moreover, at this moment, no review has been published about the effect of the newly approved antipsychotics asenapine, iloperidone and lurasidone on PRL levels. The objective of this review is to describe PRL physiology; PRL measurement; diagnosis, causes, consequences and mechanisms of HPRL; incidence figures of (new-onset) HPRL with SGAs and newly approved antipsychotics in adolescent and adult patients; and revisit lingering questions regarding this hormone. A literature search, using the MEDLINE database (1966-December 2013), was conducted to identify relevant publications to report on the state of the art of HPRL and to summarize the available evidence with respect to the propensity of the SGAs and the newly approved antipsychotics to elevate PRL levels. Our review shows that although HPRL usually is defined as a sustained level of PRL above the laboratory upper limit of normal, limit values show some degree of variability in clinical reports, making the interpretation and comparison of data across studies difficult. Moreover, many reports do not provide much or any data detailing the measurement of PRL. Although the highest rates of HPRL are consistently reported in association with amisulpride, risperidone and paliperidone, while aripiprazole and quetiapine have the most favorable profile with respect to this outcome, all SGAs can induce PRL elevations, especially at the beginning of treatment, and have the potential to cause new-onset HPRL. Considering the PRL-elevating propensity of the newly approved antipsychotics, evidence seems to indicate these agents have a PRL profile comparable to that of clozapine (asenapine and iloperidone), ziprasidone and olanzapine (lurasidone). PRL elevations with antipsychotic medication generally are dose dependant. However, antipsychotics having a high potential for PRL elevation (amisulpride, risperidone and paliperidone) can have a profound impact on PRL levels even at relatively low doses, while PRL levels with antipsychotics having a minimal effect on PRL, in most cases, can remain unchanged (quetiapine) or reduce (aripiprazole) over all dosages. Although tolerance and decreases in PRL values after long-term administration of PRL-elevating antipsychotics can occur, the elevations, in most cases, remain above the upper limit of normal. PRL profiles of antipsychotics in children and adolescents seem to be the same as in adults. The hyperprolactinemic effects of antipsychotic medication are mostly correlated with their affinity for dopamine D2 receptors at the level of the anterior pituitary lactotrophs (and probably other neurotransmitter mechanisms) and their blood-brain barrier penetrating capability. Even though antipsychotics are the most common cause of pharmacologically induced HPRL, recent research has shown that HPRL can be pre-existing in a substantial portion of antipsychotic-naïve patients with first-episode psychosis or at-risk mental state.