Differences in plasma prolactin levels in patients with schizophrenia treated on monotherapy with five second-generation antipsychotics

Sex differences in autonomic adverse effects related to antipsychotic treatment and associated hormone profiles

Autonomic adverse effects of antipsychotic drugs (APs) cause clinical challenges, but few studies have investigated sex differences and their underlying biological pathways. Sex-specific regulation of relevant hormones could be involved. We investigated sex differences in autonomic adverse effects related to olanzapine, quetiapine, risperidone, and aripiprazole, and the role of hormones related to APs. Patients with severe mental disorders (N = 1318) were included and grouped based on AP monotherapy: olanzapine (N = 364), quetiapine (N = 211), risperidone (N = 102), aripiprazole (N = 138), and no AP (N = 503). Autonomic symptoms from the Udvalg for Kliniske Undersøgelser (UKU) side effect scale was analyzed with logistic regression, adjusting for age, diagnosis, and polypharmacy. Further, we analyzed associations between autonomic symptoms and hormones related to APs. We found associations between autonomic adverse effects and APs, with sex-specific risk for palpitations/tachycardia associated with hormonal changes related to APs. Results showed increased salivation associated with aripiprazole, reduced salivation with quetiapine, and nausea/vomiting and palpitations/tachycardia with olanzapine, and higher risk of nausea/vomiting, diarrhea, constipation, polyuria/polydipsia, and palpitations/tachycardia in females. Significant sex x AP interaction was found for palpitations/tachycardia, with higher risk in risperidone-treated males, which was associated with different hormone profiles of prolactin, cortisol, and insulin. Our findings implicate a role of several hormones in the sex-specific autonomic adverse effects related to APs.

Immunoendocrine Peripheral Effects Induced by Atypical Antipsychotics

Atypical antipsychotics (AAP) or second-generation antipsychotics are the clinical option for schizophrenia treatment during acute psychoses, but they are also indicated for maintenance during lifetime, even though they are being used for other psychiatric conditions in clinical practice such as affective disorders and autism spectrum disorder, among others. These drugs are differentiated from typical antipsychotics based on their clinical profile and are a better choice because they cause fewer side effects regarding extrapyramidal symptoms (EPS). Even though they provide clear therapeutic benefits, AAP induce peripheral effects that trigger phenotypic, functional, and systemic changes outside the Central Nervous System (CNS). Metabolic disease is frequently associated with AAP and significantly impacts the patient's quality of life. However, other peripheral changes of clinical relevance are present during AAP treatment, such as alterations in the immune and endocrine systems as well as the intestinal microbiome. These less studied alterations also have a significant impact in the patient's health status. This manuscript aims to revise the peripheral immunological, endocrine, and intestinal microbiome changes induced by AAP consumption recommended in the clinical guidelines for schizophrenia and other psychiatric disorders.

Meta-analysis of the Correlation Between Schizophrenia and Breast Cancer

PURPOSE

To determine the correlation between schizophrenia and breast cancer (BC).

METHODS

We searched relevant articles indexed in the PubMed, Embase, and Cochrane Library databases; managed the data in Endnote X7 software; evaluated literature quality by Newcastle-Ottawa quality evaluation criteria; designed tables; and extracted relevant data. The main outcome measure was BC incidence. Effect values were risk ratio and 95% confidence intervals. We used Stata 13.1 software to perform the meta-analysis, choosing a corresponding combination model according to heterogeneity test results and carrying out subgroup analyses in order to better understand the stability of results through sensitivity analysis.

RESULTS

On the basis of 15 studies that assessed patients in different geographic regions, meta-analysis results showed that BC incidence between the exposure group (patients with schizophrenia) and the control group (nonschizophrenia population or general population) had statistical difference (risk ratio = 1.18; 95% confidence interval, 1.05, 1.32), thus showing that BC incidence in patients with schizophrenia is higher than in the nonschizophrenia or general population. Subgroup analysis indicated that gender and geographic region may be sources of the assessed studies' heterogeneity.

CONCLUSION

The incidence of schizophrenia is positively correlated with BC, and the incidence of BC in patients with schizophrenia is increased to a certain degree. Because of the effects of potential and publication bias, this conclusion needs more high-quality studies to increase the strength of evidence.

PROLACTIN LEVEL IN PATIENTS WITH FIRST EPISODE SCHIZOPHRENIA TREATED FOR ONE YEAR WITH ATYPICAL ANTIPSYCHOTICS

CONTEXT

Atypical antipsychotics (AAs) are the first-line treatments for schizophrenia, schizoaffective disorder and bipolar disorder. However, they are now extensively utilized as off label in a myriad of diseases despite their frequently serious metabolic side-effects and hyperprolactinemia.

OBJECTIVE

The purpose of our study was to observe long-term (one year) prolactin level change in first episode schizophrenia patients treated with one of the four AAs: olanzapine, quetiapine, amisulpride, ziprasidone.

DESIGN

This study is an analysis of the prolactin level associated with the atypical antipsychotics used in European First Episode Schizophrenia Trial (EUFEST) study.

SUBJECTS AND METHODS

Seventy-three first episode schizophrenia patients from the 113 patients, randomized to one of the four AAs treatment arms. Prolactin level was obtained at baseline, 6 and 12 months for all the four AAs. Analyses have been done for each antipsychotic separately for each sex.

RESULTS

For the male patients neither of the four antipsychotics have been associated with a statistically significant increase of prolactin level in the entire study (p>0.05). In case of the female patients, treatment with olanzapine (p=.021) and ziprasidone (p=.005) has been associated with a decrease of prolactin level in one year compared with baseline.

CONCLUSIONS

In both men and women, the administration of these four AAs is not associated with the increase of prolactin levels, moreover, in women's case, there is a reduction of prolactin values at administration of Olanzapine and Ziprasidone. These results are optimistic, suggesting that long term administration of these antipsychotics is safe regarding prolactin level.

Influence of olanzapine on serum prolactin levels and BMI in female patients with schizophrenia

OBJECTIVES

It has been well documented that elevation of serum prolactin (PRL) level and weight gain are common in patients receiving treatment with atypical antipsychotics. The existing evidences show that serum PRL is elevated in schizophrenic patients treated with olanzapine. However, little is known about the long-term effects of olanzapine on PRL levels and weight gain in female patients with schizophrenia.

MATERIALS AND METHODS

This study addressed this issue by investigating the relationship between serum PRL level and body mass index (BMI). Seventy-nine female patients with first-episode schizophrenia were recruited and received olanzapine monotherapy for 12 weeks. Serum PRL level and BMI were measured at baseline and at 4, 8, 12 weeks. Thirty-five age-matched healthy female individuals were recruited as controls. The severity of psychiatric symptoms was evaluated using the Positive and Negative Syndrome Scale.

RESULTS

The olanzapine treatment for 12 weeks significantly increased serum PRL (P<0.01) level and BMI (P<0.01). A positive correlation between the pre- and posttreatment changes in serum PRL level and BMI was observed (r=0.247, P=0.028).

CONCLUSION

Our findings suggest that PRL might conceivably modulate weight gain in female patients with schizophrenia receiving olanzapine treatment; however, the exact mechanism remains unclear.

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.

Variants in the DRD2 locus and antipsychotic-related prolactin levels: A meta-analysis

BACKGROUND

Although dopamine D2 receptor antagonists lead to dose-dependent prolactin (PRL) elevations proportionate to their D2 affinity, considerable inter-individual differences exist. We conducted a meta-analytic review of associations between genetic variations in the dopamine D2 receptor gene (DRD2) and PRL levels in antipsychotic-treated subjects.

METHODS

Systematic literature search (5/8/2015) was performed to find published studies of pharmacogenetic associations between two DRD2 variants, Taq1A (rs1800497) and -141C Ins/Del (rs1799732), and PRL levels during antipsychotic treatment (excluding aripiprazole). Patients were included independent of age or diagnosis. Random effects models were used and Hedges' g was calculated as the effect size measure. Subgroup analyses explored the effect of sex and diagnosis, (males vs females; schizophrenia vs non-schizophrenia).

RESULTS

Altogether, 11 studies (n=1034, schizophrenia-spectrum=475) for Taq1A polymorphism, and 4 studies (n=451, schizophrenia-spectrum=274) for -141C Ins/Del polymorphism, each reporting on PRL levels but not on the proportion of patients with hyperprolactinemia, were meta-analyzed. Across all patients, there was no statistically significant association between PRL levels and either DRD2 Taq1A genotype or DRD2 -141C Ins/Del genotype. However, in patients with schizophrenia, PRL levels were significantly higher in DRD2 Taq1A A1 carriers than A1 non-carriers (studies=5, n=475, Hedges' g=0.250, 95% CI=0.068-0.433, p=0.007, I(2)=0%).

DISCUSSION

Although there was no significant association between either DRD2 Taq1A genotype or DRD2 -141C Ins/Del genotype and PRL levels in all included patients, our results suggest that DRD2 Taq1A genotype may affect antipsychotic-related PRL levels in patients with schizophrenia. Because of the small sample size, further studies are needed to confirm these results.

Systematic Literature Review of the Methods Used to Compare Newer Second-Generation Agents for the Management of Schizophrenia: A focus on Health Technology Assessment

BACKGROUND

The challenges of comparative effectiveness to support health technology assessment (HTA) agencies are important considerations in the choices of antipsychotic medications for the treatment of schizophrenia.

OBJECTIVES

Our aim was to assess the study methods used and outcomes reported in the published literature to address the question of comparative effectiveness of newer antipsychotic agents and the adequacy and availability of evidence to support HTA agencies.

DATA SOURCE

A systematic search of the PubMed database from 1 January 2009 to 30 September 2013 was conducted to identify studies evaluating new atypical antipsychotics reporting on comparative effectiveness.

STUDY SELECTION

The systematic review comprised of studies on schizophrenia patients where at least two drugs were being compared and at least one treatment group received one of the following second-generation antipsychotics: risperidone, olanzapine, aripiprazole, paliperidone, asenapine, iloperidone, lurasidone, and quetiapine. The included studies were also required to have an efficacy, safety or economic outcome, such as Positive and Negative Syndrome Scale (PANSS) score, weight gain, resource utilization, or costs.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two reviewers (BW and GK) independently applied the inclusion criteria. Disagreements between reviewers were resolved by consensus, referring to the original sources. Information on the methodology and outcomes was collected for each included study. This included study description, head-to-head drug comparison, patient population, study methodology, statistical methods, reported outcomes, study support, and journal type.

RESULTS

A total of 198 studies were identified from electronic search methods. The largest category of studies was randomized controlled trials [RCTs] (N = 73; 36.9%), which were largely directed at the regulatory endpoint. Fewer studies were undertaken for HTA-purposes cohort studies (N = 53; 26.8%), meta-analyses (N = 32; 16.2%), economic studies (N = 14; 7.1%), and cross-sectional studies (N = 13; 6.6%). Direct head-to-head comparisons preferred by HTA were dominated by the comparison involving olanzapine and risperidone, representing 149 (75.3%) and 119 (60.1%) studies, respectively. RCTs, which are the primary study type for regulatory submissions, showed a lack of bias. Studies aimed at HTA were not as well performed. Cohort studies suffered from bias in the selection of comparison groups, lack of control for confounders, and differential dropout rates. As a group, cross-sectional studies scored poorly for bias, with a primary failure to identify a representative sample. Economic studies showed highly variable bias, with bias in the representation of effectiveness data, model assumptions without validation, and lack of sensitivity analyses.

LIMITATIONS

One limitation of this systematic review is that it only included studies from 2009 to 2013, potentially excluding some earlier comparator studies, particularly those involving first-generation antipsychotics.

CONCLUSIONS

This review of comparative effectiveness studies of second-generation antipsychotic agents for schizophrenic patients revealed a wide range of study types, study methodologies, and outcomes. For traditional efficacy outcomes and select safety outcomes, there is strong evidence from many well-conducted studies; however, there are fewer studies of types preferred by HTA with limited head-to-head comparisons and a higher risk of bias in the execution of these studies.

Postprandial prolactin suppression appears absent in antipsychotic-treated male patients

INTRODUCTION

Hyperprolactinemia is a common side-effect of antipsychotic treatment. Antipsychotics and hyperprolactinemia are both considered risk factors of metabolic disturbances and diabetes. Investigations on prolactin response to meal ingestion in antipsychotic-treated patients are missing.

MATERIAL AND METHODS

In a case-control design, 49 antipsychotic-treated, clinically stable, non-diabetic, schizophrenia spectrum male patients were compared with 93 healthy male controls by age (33.1, SD 7.4 vs. 32.9, SD 6.6 years), body mass index (26.2, SD 4.6 vs. 26.1, SD 3.9 kg/m(2)) and waist circumference (96.4, SD 13.0 vs. 96.7, SD 11.9 cm). Serum-prolactin was measured in the morning and 90 min after ingestion of a standardized liquid meal (2268 kJ).

RESULTS

Fasting prolactin levels varied considerably, and mean fasting prolactin levels did not significantly differ between patients and controls (12.33, SD 11.58 vs. 10.06, SD 8.67 ng/ml, p = 0.623). In the controls, postprandial serum prolactin was significantly reduced (Δ -2.53, SD 9.75 ng/ml, p = 0.016). In antipsychotic-treated patients postprandial serum prolactin tended to increase (Δ 2.62, SD 10.96 ng/ml, p = 0.081). Analyses of subgroups based on the prolactinogenic liability of their antipsychotic treatment indicated 22 to 65% higher postprandial prolactin levels with high and intermediate prolactinogenic antipsychotics.

DISCUSSION

A physiological postprandial suppression of serum prolactin appears absent in antipsychotic-treated males. Marked variability in fasting prolactin levels may reflect individual variations in the diurnal cycle. Uniform acquisition procedures accounting for diurnal variation and food intake may enhance reliability of prolactin levels in antipsychotic-treated male patients.

Adjunctive aripiprazole in the treatment of risperidone-induced hyperprolactinemia: A randomized, double-blind, placebo-controlled, dose-response study

Hyperprolactinemia is an unwanted adverse effect associated with several antipsychotics. The addition of partial dopamine receptor agonist aripiprazole may attenuate antipsychotic-induced hyperprolactinemia effectively. However, the ideal dosing regimen for this purpose is unknown. We aimed to evaluate the dose effects of adjunctive treatment with aripiprazole on prolactin levels and hyperprolactinemia in schizophrenia patients. Stable subjects 18-45 years old with schizophrenia and hyperprolactinemia (i.e., >24 ng/ml for females and >20 ng/ml for males) were randomly assigned to receive 8 weeks of placebo (n=30) or oral aripiprazole 5mg/day (n=30), 10mg/day (n=29), or 20mg/day (n=30) added on to fixed dose risperidone treatment. Serum prolactin levels were measured at baseline and after 2, 4 and 8 weeks; clinical symptoms and side effects were assessed at baseline and week 8 using the Positive and Negative Syndrome Scale, Clinical Global Impressions Severity scale, Barnes Akathisia Scale, Simpson-Angus Scale and UKU Side Effects Rating Scale. Of 119 randomized patients, 107 (89.9%) completed the 8-week study. At study end, all three aripiprazole doses resulted in significantly lower prolactin levels (beginning at week 2), higher response rates (≥30% prolactin reduction) and higher prolactin normalization rates than placebo. Effects were significantly greater in the 10 and 20mg/day groups than the 5mg/day group. No significant changes were observed in any treatment groups regarding psychopathology and adverse effect ratings. Adjunctive aripiprazole treatment was effective and safe for resolving risperidone-induced hyperprolactinemia, producing significant and almost maximal improvements by week 2 without significant effects on psychopathology and side effects.

The influence of atypical antipsychotic drugs on sexual function

Human sexuality is contingent upon many biological and psychological factors. Such factors include sexual drive (libido), physiological arousal (lubrication/erection), orgasm, and ejaculation, as well as maintaining normal menstrual cycle. The assessment of sexual dysfunction can be difficult due to the intimate nature of the problem and patients' unwillingness to discuss it. Also, the problem of dysfunction is often overlooked by doctors. Atypical antipsychotic treatment is a key component of mental disorders' treatment algorithms recommended by the National Institute of Health and Clinical Excellence, the American Psychiatric Association, and the British Society for Psychopharmacology. The relationship between atypical antipsychotic drugs and sexual dysfunction is mediated in part by antipsychotic blockade of pituitary dopamine D2 receptors increasing prolactin secretion, although direct correlations have not been established between raised prolactin levels and clinical symptoms. Variety of mechanisms are likely to contribute to antipsychotic-related sexual dysfunction, including hyperprolactinemia, sedation, and antagonism of a number of neurotransmitter receptors (α-adrenergic, dopaminergic, histaminic, and muscarinic). Maintaining normal sexual function in people treated for mental disorders can affect their quality of life, mood, self-esteem, attitude toward taking medication, and compliance during therapy.

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.