Antipsychotics: impact on prolactin levels

Minimal Effects of Cariprazine on Prolactin Levels in Bipolar Disorder and Schizophrenia

BACKGROUND

Many medications used to treat schizophrenia and bipolar I disorder are linked to hyperprolactinemia. The effects of cariprazine, a dopamine D₃/D₂ receptor partial agonist, on prolactin levels in patients with schizophrenia or bipolar I disorder were evaluated.

METHODS

Effects on prolactin were evaluated using pooled data from randomized, double-blind, placebo-controlled studies in patients with schizophrenia (4 studies; 6-week duration; cariprazine 1.5-3 mg/d, 4.5-6 mg/d, and 9-12 mg/d), bipolar mania (3 studies; 3-week duration; cariprazine 3-6 and 9-12 mg/d), and bipolar depression (3 studies; 6- to 8-week duration; cariprazine 1.5 and 3 mg/d). Long-term effects were analyzed using open-label studies in patients with schizophrenia (2 studies; 48-week duration) and patients with bipolar mania (1 study; 16-week duration). Change in prolactin levels (ng/mL) from baseline to study endpoint was evaluated in subsets of sex and prior medication use.

RESULTS

In patients with schizophrenia (male, n = 1377; female, n = 558), median prolactin changes were -1.2 for males and -7.4 for females on placebo, and ranged from -4.2 to -3.6 for males and -12.4 to +0.2 for females in the cariprazine-treatment groups. In patients with bipolar mania (male, n = 570; female, n = 395), median prolactin changes were -0.2 for males and -1.1 for females on placebo and ranged from -2.1 to -3.0 for males and 0 to +1.8 for females in the cariprazine-treatment groups. Median decreases were also seen in the long-term studies of schizophrenia (range, -14.6 to -2.0) and bipolar mania (range, -0.8 to +1.9). In patients with bipolar depression (male, n = 485; female, n = 780), median prolactin changes were +0.3 for males and +0.7 for females on placebo and ranged from +0.4 to +0.5 for males and +3.0 to +3.1 for females in the cariprazine-treatment groups.

CONCLUSION

Treatment with cariprazine for schizophrenia or bipolar I disorder was associated with minimal effects on prolactin levels.

Cognitive Deficit in Schizophrenia: From Etiology to Novel Treatments

Schizophrenia is a major mental illness characterized by positive and negative symptoms, and by cognitive deficit. Although cognitive impairment is disabling for patients, it has been largely neglected in the treatment of schizophrenia. There are several reasons for this lack of treatments for cognitive deficit, but the complexity of its etiology-in which neuroanatomic, biochemical and genetic factors concur-has contributed to the lack of effective treatments. In the last few years, there have been several attempts to develop novel drugs for the treatment of cognitive impairment in schizophrenia. Despite these efforts, little progress has been made. The latest findings point to the importance of developing personalized treatments for schizophrenia which enhance neuroplasticity, and of combining pharmacological treatments with non-pharmacological measures.

Erectile and Ejaculatory Dysfunction Associated with Use of Psychotropic Drugs: A Systematic Review

BACKGROUND

Sexual dysfunction may be a side effect of treatment with antipsychotics, antidepressants, and other psychotropic drugs.

AIM

To review the evidence concerning male sexual dysfunctions in patients taking psychotropic drugs to provide specific information to nonpsychiatric physicians for the management of these dysfunctions.

METHODS

A systematic search of Medline and Embase databases was performed up to October 15th, 2020. We included randomized controlled trials comparing the effects of psychotropic drugs versus placebo or versus another drug of the same class, for at least 5 weeks.

OUTCOMES

We considered studies whose male population could be evaluated separately from the female population and with a separate analysis of the different phases of the male sex cycle.

RESULTS

We included 41 studies in the final review. There was a significant association between sexual dysfunction and antidepressant drug therapy, compared to placebo (decreased libido OR 1.89, 95% CI:1.40 to 2.56, 22 series, 11 trials, 7706 participants; erectile dysfunction OR = 2.28, 95% CI: 1.31 to 3.97; 11 trials, 3008 participants; ejaculatory dysfunction OR = 7.31, 95% CI: 4.38 to 12.20,19 trials, 3973 participants). When the effects of selective serotonin reuptake inhibitors (SSRIs) were evaluated separately from those of serotonin/norepinephrine reuptake inhibitors (SNRIs), the use of SNRIs but not that of SSRIs was characterized by significantly higher odds of erectile dysfunction compared to placebo. Only limited data were found regarding the effects of antipsychotics on the phases of the male sexual cycle, as it was shown that aripiprazole and risperidone showed lower and higher odds for erectile or ejaculatory dysfunction, respectively, compared to other atypical antipsychotics.

CLINICAL IMPLICATIONS

Treatment of male sexual dysfunction in patients taking psychotropics requires a basic knowledge of the different drugs that affect sexual function with different mechanisms.

STRENGTHS & LIMITATIONS

The effects of psychotropic drugs on erectile function and ejaculation were evaluated separately. The great variability of the mechanisms of action makes it difficult to make comparisons between the effects of the different classes of psychotropic drugs.

CONCLUSIONS

Administration of antipsychotics affects male sexual function with different mechanisms, although the increase in prolactin values associated with the administration of first-generation antipsychotics and some atypical, such as risperidone, seems to play a primary role in determining male sexual dysfunction. Most antidepressants cause decreased libido, ejaculatory and erectile dysfunction, however the administration of SNRIs appears to be possibly associated with a specific risk of erectile dysfunction. Trinchieri M, Trinchieri M, Perletti G, et al. Erectile and Ejaculatory Dysfunction Associated with Use of Psychotropic Drugs: A Systematic Review. J Sex Med 2021;18:1354-1363.

Male Breast Carcinoma after Irradiation and Long-Term Phenothiazine Exposure: A Case Report

We present a young male patient with breast cancer having several risk factors likely acting in consort: irradiation of the breast for gynecomastia in adolescence and a life-long administration of phenothiazine for schizophrenia from the age of 16 years, with elevated serum prolactin level resulting in breast cancer development 24 years after irradiation.

Antipsychotic-induced Hyperprolactinemia in aging populations: Prevalence, implications, prevention and management

This paper reviews the prevalence, implications, prevention and management of antipsychotic-induced hyperprolactinemia in aging populations. Antipsychotics are indicated mainly for the treatment of psychotic illness but are also used in other conditions. Complications induced by antipsychotics increase with age, due to age-related changes in drug metabolism and excretion. Almost all antipsychotics lead to hyperprolactinemia by blocking dopamine D2 receptors in the anterior pituitary gland, which counteracts dopamine's inhibitory action on prolactin secretion. The main findings of this narrative review are that, though many of the known side effects of high prolactin levels lose their salience with age, the risk of exacerbating osteoporosis remains critical. Methods of preventing antipsychotic-induced hyperprolactinemia in older individuals include using antipsychotic medication (AP) as sparingly as possible and monitoring AP serum levels, regularly measuring prolactin levels, closely monitoring bone density, treating substance abuse, and teaching patients stress management techniques. When hyperprolactinemia symptoms cannot be otherwise managed, adjunctive drugs are available. Potential helpful adjuncts are: dopamine agonists, antipsychotics with partial agonist properties (e.g. aripiprazole), selective estrogen receptor modulators, and metformin. Because a gold standard for prevention/treatment has not been established, clinical decisions need to be made based on safety and individual circumstance.

Sexual dysfunction in patients with schizophrenia on antipsychotic medication

Objective

The objective of this study was to determine the prevalence of sexual dysfunction in patients with schizophrenia under antipsychotic therapy and to investigate the effect of various parameters on sexual dysfunction.

Method

A total of 827 stabilized outpatients who met DSM-IV criteria for schizophrenia, were recruited in the study. Arizona Sexual Experience Scale (ASEX) and the subscale on sexual function of the UKU Side Effects Rating Scale were applied at a single interview.

Results

In total, 52.6% of the patients had sexual dysfunction, 54.2% reported a low sexual desire and 41.7% reported problems in having an orgasm. Erectile dysfunction and ejaculation problems were seen in 48.1% and 64.2% of the men, respectively; amenorrhea was seen in 24.9% of the women. ASEX score and severity of disease were found to be correlated (p = 0.02). Higher ASEX scores were observed in patients who smoked (p = 0.01). Men receiving atypical monotherapy had lower ASEX scores than those receiving a combination of atypical and conventional antipsychotics (p = 0.017). Patients on combination therapy had more ejaculation problems than the atypical group (p = 0.001). Low sexual desire was more prevalent among women using conventional drugs than those on atypical drugs (p = 0.004). In linear regression analyses, ASEX was affected significantly and independently by the severity of the disease only in men (p = 0.005).

Conclusion

Our results show that sexual dysfunction is widespread among patients with schizophrenia on antipsychotic medications.

Gender differences in the prevalence, comorbidities and antipsychotic prescription of early-onset schizophrenia: a nationwide population-based study in Taiwan

Early-onset schizophrenia (EOS) is defined as patients diagnosed with schizophrenia before the age of 18. Whether the EOS population has gender differences is currently a matter of considerable debate. This study used a representative nationwide sample to examine potential gender differences in the prevalence, comorbidities, and prescription of antipsychotics among the EOS population. We identified a total of 401 patients with EOS (200 males and 201 females) from Taiwan's National Health Insurance Database between 2000 and 2012. The annual prevalence rate of overall patients with EOS increased significantly from 17.1 to 41.8 per 100,000 persons among the youth population (≤ 18 years). Sulpiride, Risperidone, and Aripiprazole were the most common antipsychotics of first choice for treating EOS. Compared to female patients, male patients were more likely to experience the following comorbidities: attention deficit hyperactivity disorder (15.5% vs. 5.5%), autism spectrum disorder (10.0% vs. 3.0%), intellectual disability (19.0% vs. 10.4%), developmental disorder (8.0% vs. 3.0%), and history of physical injury (65.5% vs. 48.8%), prior to being diagnosed with schizophrenia. We observed no significant gender differences with regard to incidence, prevalence, age of onset, and categories and doses of patients' first antipsychotic prescription. Our findings did not support the empirical opinion that males with EOS experience the onset earlier or are more prevalent than EOS female patients. However, male patients were more likely to have neurodevelopmental comorbidities and a history of physical injury. These results can function as an important reference for planning services that target real-world patient treatment.

Recent evidence and potential mechanisms underlying weight gain and insulin resistance due to atypical antipsychotics

OBJECTIVE

Atypical antipsychotics (AAPs) promote obesity and insulin resistance. In this regard, the main objective of this study was to present potential mechanisms and evidence concerning side effects of atypical antipsychotics in humans and rodents.

METHOD

A systematic review of the literature was performed using the MEDLINE database. We checked the references of selected articles, review articles, and books on the subject.

RESULTS

This review provides consistent results concerning the side effects of olanzapine (OL) and clozapine (CLZ), whereas we found conflicting results related to other AAPs. Most studies involving humans describe the effects on body weight, adiposity, lipid profile, and blood glucose levels. However, it seems difficult to identify an animal model replicating the wide range of changes observed in humans. Animal lineage, route of administration, dose, and duration of treatment should be carefully chosen for the replication of the findings in humans.

CONCLUSIONS

Patients undergoing treatment with AAPs are at higher risk of developing adverse metabolic changes. This increased risk must be taken into account when making decisions about treatment. The influence of AAPs on multiple systems is certainly the cause of such effects. Specifically, muscarinic and histaminergic pathways seem to play important roles.

Hormone profile in acute psychotic disorders: A cross-sectional comparison of serum hormone concentrations in treated and untreated male patients with schizophrenia

BACKGROUND

Antipsychotic drugs for the treatment of schizophrenia provide effective treatment of psychotic symptoms but might lead to neuroendocrine abnormalities.

OBJECTIVE

The aim of this study was to assess hypothalamic-pituitary-gonadal (HPG) axis function by comparing serum hormone profiles of newly admitted patients with psychotic disorders who were receiving antipsychotic drugs with those who were antipsychotic-drug-free during the preceding 6 months.

METHODS

Adult male patients admitted during a 1-year period (December 1999 to December 2000) to 1 of 2 Brazilian public psychiatric inpatient units that provide care for severely ill patients were eligible for this cross-sectional study if they had a diagnosis of schizophrenia based on the criteria given in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and a score >24 on the Brief Psychiatric Rating Scale. On the morning after admission, serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), prolactin, free testosterone (FT), and total testosterone (TT) were determined. A commercial laboratory provided the normal serum hormone concentrations of healthy Brazilian men in the same age range as that of the study patients.

RESULTS

Sixty-three adult male patients, aged 18 to 55, were included in the study. Forty-eight (76.2%) patients (mean [SD] age, 30.6 [8.9] years) were receiving antipsychotic drugs (treated). Fifteen (23.8%) patients (mean [SD] age, 36.5 [9.8] years) were antipsychotic-drug-free for 6 months before admission (untreated). The only significant between-group difference was for disease duration (treated, 7.6 [8.1] years vs untreated, 12.3 [9.7] years; P = 0.044). Treated patients were more likely to have higher dispersed serum hormone concentrations than the untreated patients. Serum concentration of FSH was numerically higher in the treated patients than in the untreated patients, although the difference was not statistically significant. Compared with the control group (1436 men and women for prolactin; 226 men for LH; 207 for FSH; 128 for TT; 128 for FT; and 128 for SHBG), patients in the treated group had significantly different mean [SD] serum concentrations of all hormones (treated vs control: prolactin, 24.3 [23.7] μg/L vs 6.8 [0.12] μg/L, P < 0.001; LH, 4.9 [3.4] U/L vs 3.3 [0.13] U/L, P = 0.001; FSH, 4.4 [3.9] U/L vs 3.0 [0.06] U/L, P = 0.025; TT, 17.5 [7.8] nmol/L vs 20.1 [1.64] nmol/L, P = 0.004; FT, 0.056 [0.08] nmol/L vs 0.06 [0.003] nmol/L, P < 0.001; and SHBG, 33.3 [18.9] nmol/L vs 48.4 [1.45] nmol/L, P= 0.002). Compared with the control group, patients in the untreated group had significantly different mean (SD) serum concentrations of all hormones except FSH and TT (untreated vs control: prolactin, 19.9 [12.8] μg/L vs 6.8 [0.12] μg/L, P = 0.001; LH, 6.0 [1.9] U/L vs 3.3 [0.13] U/L, P = 0.002; FT, 0.08 [0.04] nmol/L vs 0.06 [0.003] nmol/L, P= 0.001; and SHBG, 26.6 [11.6] nmol/L vs 48.4 [1.45] nmol/L, P < 0.001). No differences were found between the TT distribution curve of the control group and that of the untreated patients.

CONCLUSION

This study supports further investigation of a potential difference in the HPG axis among treated and untreated patients with schizophrenia and those who do not have that condition.

Differential responses to JNJ-37822681, a specific and fast dissociating dopamine D2 receptor antagonist, in cynomolgus monkey and Sprague-Dawley rat general toxicology studies: clinical observations, prolactin levels, mammary histopathology findings and toxicokinetics

JNJ-37822681 is a potent, specific and fast dissociating dopamine D2 receptor antagonist intended for the treatment of schizophrenia. Its nonclinical toxicological profile was investigated in a series of general repeat dose toxicity studies in cynomolgus monkeys and Sprague-Dawley rats. The maximum duration of treatment was 9 and 6 months, respectively. Interspecies differences were noted in the response to JNJ-37822681 in terms of extrapyramidal (EPS)-like clinical signs and prolactin-mediated tissue changes in the mammary gland. Monkeys showed severe EPS-like clinical signs such as abnormal posture, abnormal eye movements and hallucination-like behavior at relatively low exposures compared to those associated with EPS in patients with schizophrenia. The high sensitivity of the monkey to JNJ-37822681-induced EPS-like signs was unexpected based on the fast dissociating properties of the compound. Rats, however, were not prone to EPS. Elevated serum prolactin levels were found in rats and monkeys. While rats showed slight to moderate prolactin-related tissue changes upon histopathological examination in all studies, which among others affected the mammary gland, only minor mammary gland tissue changes were noted in monkeys. Prolactin levels were only slightly increased in patients with schizophrenia receiving relatively high dose levels of JNJ-37822681. The monkey toxicology studies did not provide an exposure-based safety margin, while in rats adverse effects were only noted at exposures considerably higher than those achieved at efficacious plasma concentrations in the clinic. Overall, the available data suggest that the cynomolgus monkey showed better predictivity towards the nature of JNJ-37822681-associated adverse events in humans than the Sprague-Dawley rat.

Effect of the addition of aripiprazole on hyperprolactinemia associated with risperidone long-acting injection

We sought to assess the effect of the addition of a fixed dose of 5 mg daily of aripiprazole on hyperprolactinemia induced by risperidone long-acting injectable (RLAI) treatment in patients with chronic psychoses and the adverse events related to the addition of aripiprazole and its impact on the disease. This is an open uncontrolled clinical trial with 13 patients with a severe mental disorder (schizophrenia and other unspecified psychoses) treated with RLAI and with increased serum prolactin levels. Subjects received the addition of a fixed dose of 5 mg daily of aripiprazole for 3 months. The main efficacy outcome was the change in serum prolactin levels after 3 months of treatment. Twelve of the 13 patients showed a decrease in serum prolactin levels (81 ± 46 μg/L at baseline vs 42 ± 21 μg/L at month 1, P < 0.001, 52% mean reduction). In 2 patients, prolactin levels reverted normality. In 8 patients who continued treatment for 2 more months, the decrease in prolactin levels was maintained. Symptoms associated with hyperprolactinemia improved, and no worsening of the Clinical Global Impression Scale scores was observed. The adverse effects due to the addition of aripiprazole were mild and transient. The addition of aripiprazole 5 mg daily to RLAI was associated with a significant decrease in hyperprolactinemia levels and no major additional toxicity in patients with chronic psychosis.

Weight Gain While Switching from Polypharmacy to Ziprasidone: A Case Report

Second-generation antipsychotics (SGAs), valproate, and sulpiride are related to significant weight gain and risk of metabolic syndrome (MetS). Among SGAs, olanzapine and clozapine are associated with the highest metabolic risk while ziprasidone is among one of the SGAs with the lowest risk. Several reports suggest that weight loss is observed in switching other antipsychotics to ziprasidone. Here we describe a female patient with chronic paranoid schizophrenia who had an unexpected weight gain and developed MetS during a cross-switch from a polypharmacy of olanzapine, valproate and sulpiride to ziprasidone monotherapy.

Clinical pharmacology of dopamine-modulating agents in Tourette's syndrome

Forty years of research and clinical practice have proved dopamine (DA) receptor antagonists to be effective agents in the treatment of Tourette's syndrome (TS), allowing a significant tic reduction of about 70%. Their main effect seems to be mediated by the blockade of the striatal DA-D2 receptors. Various typical and atypical agents are available and there is still discord between experts about which of them should be considered as first choice. In addition, there are suggestions to use DA receptor agonists such as pergolide or non-DA-modulating agents. The present chapter is focusing on the clinical pharmacology of DA-modulating agents in the treatment of TS. The introduction outlines their clinical relevance and touches on the hypotheses of the role of DA in the pathophysiology of TS. Subsequently, general information about the mechanisms of action and adverse effects are provided. The central part of the chapter forms a systematic review of all DA-modulating agents used in the treatment of TS, including an overview of studies on their effectiveness, and a critical discussion of their specific adverse effects. The present chapter closes with a summary of the body of evidence and a description of the resulting recommendations for the pharmacological treatment of TS.

A gene expression and systems pathway analysis of the effects of clozapine compared to haloperidol in the mouse brain implicates susceptibility genes for schizophrenia

Clozapine has markedly superior clinical properties compared to other antipsychotic drugs but the side effects of agranulocytosis, weight gain and diabetes limit its use. The reason why clozapine is more effective is not well understood. We studied messenger RNA (mRNA) gene expression in the mouse brain to identify pathways changed by clozapine compared to those changed by haloperidol so that we could identify which changes were specific to clozapine. Data interpretation was performed using an over-representation analysis (ORA) of gene ontology (GO), pathways and gene-by-gene differences. Clozapine significantly changed gene expression in pathways related to neuronal growth and differentiation to a greater extent than haloperidol; including the microtubule-associated protein kinase (MAPK) signalling and GO terms related to axonogenesis and neuroblast proliferation. Several genes implicated genetically or functionally in schizophrenia such as frizzled homolog 3 (FZD3), U2AF homology motif kinase 1 (UHMK1), pericentriolar material 1 (PCM1) and brain-derived neurotrophic factor (BDNF) were changed by clozapine but not by haloperidol. Furthermore, when compared to untreated controls clozapine specifically regulated transcripts related to the glutamate system, microtubule function, presynaptic proteins and pathways associated with synaptic transmission such as clathrin cage assembly. Compared to untreated controls haloperidol modulated expression of neurotoxic and apoptotic responses such as NF-kappa B and caspase pathways, whilst clozapine did not. Pathways involving lipid and carbohydrate metabolism and appetite regulation were also more affected by clozapine than by haloperidol.

Slow dissociation of partial agonists from the D₂ receptor is linked to reduced prolactin release

In this study we investigated the correlation between affinity, efficacy, peripheral receptor occupancy, and kinetic properties of D₂ dopamine receptor ligands with time-course evaluations of prolactin release in rat blood. We profiled typical and atypical antipsychotic antagonists at D₂ receptors, the partial agonist aripiprazole, and four novel partial agonist compounds with different properties. Clozapine and quetiapine revealed lower prolactin release and fast dissociation kinetics, linking fast dissociation and prolactin-sparing properties. Surprisingly, haloperidol, a highly prolactin-releasing antagonist, shared intermediate dissociation properties. Factors other than kinetic properties may thus contribute to prolactin-releasing properties of antagonists. Partial agonists sharing similar efficacies and receptor occupancies differed markedly in their ability to induce hyperprolactinaemia. Aripiprazole moderately released prolactin even at high receptor occupancies, with slow dissociation from D₂ receptors. Other compounds displaying low affinities and fast dissociations released prolactin substantially, although less than haloperidol. The effect augmented after repeated administrations. Compounds with high affinities and slow dissociation rates stimulated moderate prolactin release at high receptor occupancies, reaching a ceiling effect at 50-60% occupancy. Moreover, the effect developed tolerance. In conclusion, we investigated the affinity and kinetic properties of D₂ partial agonists associated with their ability to induce prolactin release in blood. We propose that for D₂ partial agonists, at comparable intrinsic activities and peripheral occupancies, the prolactin-releasing properties are linked to their kinetic rate properties. Differently from D₂ antagonists, partial agonists display slow dissociation and high affinity associated with a low prolactin release profile.

Case Based Clinical Pearls: A schizophrenic case study

Clinical pearls based on the treatment of a patient with schizophrenia who had stabbed a taxi cab driver are discussed in this case study. Areas explored include the pharmacokinetics of fluphenazine decanoate, strategies to manage clozapine-associated agranulocytosis, and approaches to addressing hyperprolactinemia.

Prolactin as a biomarker for treatment response and tardive dyskinesia in schizophrenia subjects: old thoughts revisited from a genetic perspective

Previous studies investigated whether prolactin (PRL) serum level was a biomarker of antipsychotic response, schizophrenia symptomatology, and tardive dyskinesia. Most of the findings support that antipsychotic drugs modulate PRL levels but PRL is not a steady indicator. Recent results suggest a genetic effect of PRL and PRL receptor (PRLR) polymorphisms in PRL levels indicating that independently of antipsychotic therapy subjects could have altered PRL levels due to their genetic background.We evaluated whether PRL and PRLR variants were associated with treatment outcome and tardive dyskinesia. We observed no association of PRL/PRLR polymorphism with treatment response (best genotypic results include PRL rs849885 and PRLR rs4703509 permuted p=0.326). Regarding tardive dyskinesia, the major allele of PRL rs37364 was nominally associated with risk for tardive dyskinesia in the European ancestry sub-sample (permuted p=0.183). Although we reported no significant associations, it is definitely worthy of investigation to see if together (genetic variants in the PRL system and PRL serum measures) could be a reliable biomarker for antipsychotic response and TD prevalence. Our results suggest that more studies in this context are required to shed light in the molecular mechanisms underlying antipsychotic response and tardive dyskinesia occurrence.

Double-blind comparison of ziprasidone and risperidone in the treatment of Chinese patients with acute exacerbation of schizophrenia

BACKGROUND

The aim of the study was to evaluate the efficacy and safety of ziprasidone versus risperidone in Chinese subjects with acute exacerbation of schizophrenia.

METHODS

In patients meeting the Chinese Classification of Mental Disorders criteria for schizophrenia and with a Positive and Negative Syndrome Scale (PANSS) total score ≥60 were randomly assigned to six weeks of double-blind treatment with ziprasidone 40-80 mg twice daily or risperidone 1-3 mg bid, flexibly dosed. Noninferiority was demonstrated if the upper limit of the two-sided 95% confidence interval (CI) for the difference in PANSS total score improvement from baseline in the evaluable population was smaller than the prespecified noninferiority margin of 10 units.

RESULTS

The intent-to-treat population comprised 118 ziprasidone-treated and 121 risperidone-treated subjects. Improvement (reduction) from baseline to week 6 in PANSS total score was (-35.6 [95% CI: -38.6, -32.6]) for ziprasidone and (-37.1 [95% CI: -39.9, -34.4]) for risperidone. Noninferiority was demonstrated in the evaluable population with a difference score of 1.5 [95% CI: -2.5, 5.5]. Mean prolactin levels decreased at week 6 compared with baseline for ziprasidone (-3.5 ng/mL), but significantly increased for risperidone (61.1 ng/mL; P < 0.001). More risperidone-treated subjects (14.9%) than ziprasidone-treated subjects (4.2%) reported weight gain ≥7%. Akathisia and somnolence in the ziprasidone group and akathisia and insomnia in the risperidone group were the most common side effects. Treatment-related/treatment-emergent adverse events were reported by 79.7% and 71.1% of ziprasidone-treated and risperidone-treated subjects, respectively.

CONCLUSION

In Chinese subjects, ziprasidone was as effective as risperidone, with less weight gain and less prolactin elevation.

Metabolic, digestive, and reproductive adverse events associated with antimanic treatment in children and adolescents: a retrospective cohort study

OBJECTIVE

To identify factors associated with incident metabolic and reproductive adverse events in children and adolescents.

METHOD

A retrospective cohort design evaluating Medicaid medical and pharmacy claims made in South Carolina between January 1996 and December 2005 was employed for 3,657 children and adolescents (aged 17 years old and younger) prescribed 1 of 3 antimanic medications (ie, lithium, carbamazepine, or valproic acid derivatives) and a random sample of 4,500 children and adolescents not treated with psychotropic medications.

RESULTS

Compared to the control sample, the treated cohort was more likely to be diagnosed with obesity/weight gain (odds ratio [OR] = 1.89), type 2 diabetes mellitus (OR = 2.50), dyslipidemia (OR = 1.89), nausea (OR = 1.61), anorexia (OR = 3.85), and sexual/reproductive adverse events (OR = 2.04). Within the treated cohort, incident dyslipidemia was more likely for those prescribed carbamazepine (OR = 1.52) compared to valproate and coprescribed antipsychotics (OR = 1.47) or selective serotonin reuptake inhibitors (SSRIs) (OR = 1.49) compared to those not taking antipsychotics or taking serotonin-norepinephrine reuptake inhibitor/heterocyclic (SNRI/other) antidepressants. The odds of developing nausea/vomiting were higher for those prescribed carbamazepine (OR = 1.70) or lithium (OR = 1.49) compared to valproate, and those coprescribed psychostimulants (OR = 1.25) compared to those not taking psychostimulants. The odds of developing obesity/weight gain and type 2 diabetes mellitus were higher for those coprescribed SSRIs (ORs = 1.72, 2.58) or antipsychotics (ORs = 1.69, 1.77) compared to those taking SNRI/other antidepressants or not taking antipsychotics. Incident sexual/reproductive adverse events were more likely for those coprescribed SSRIs (OR = 2.02) compared to those taking SNRI/other antidepressants.

CONCLUSION

Commonly employed psychotropic agents are associated with clinically significant metabolic, digestive, and reproductive-related adverse events. Treatment decisions in young populations are usefully informed by the somatic consequences of the medication options.

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.

Evidence for the partial dopamine-receptor agonist aripiprazole as a first-line treatment of psychosis in patients with iatrogenic or tumorogenic hyperprolactinemia

BACKGROUND

Antipsychotic drugs have many side effects, including elevation of prolactin levels through tuberoinfundibular dopamine-receptor blockade. Although a number of studies claim that aripiprazole is a prolactin-sparing antipsychotic drug that may even lower prolactin levels, there has not been an exhaustive evaluation of this claim.

OBJECTIVE

The authors analyzed the burgeoning literature suggesting that aripiprazole is efficacious in treating iatrogenic and tumorogenic hyperprolactinemia.

METHOD

The authors conducted a literature search for case studies, reports, and placebo-controlled trials that measured prolactin levels in adult patients taking aripiprazole.

RESULTS

The search identified 17 studies, in which 3,489 psychotic patients were given aripiprazole alone, as an adjuvant to haloperidol or risperidone, or to treat psychosis with a concomitant prolactinoma. Across all studies, aripiprazole lowered prolactin levels an average of 74.3%, even in psychotic patients with prolactinoma, whereas haloperidol and risperidone increased prolactin levels by as much as 272%.

CONCLUSION

These findings suggest that aripiprazole may play an important niche role in treating psychotic patients sensitive to elevated prolactin and patients with prolactin-secreting pituitary tumors.

Neuroendocrine-related adverse events associated with antidepressant treatment in children and adolescents

There is only limited community-based practice safety information available regarding antidepressant use in pediatric patients. This study identifies the factors associated with incident neuroendocrine-related metabolic, digestive, and sexual/reproductive adverse events in children and adolescents treated with antidepressants. A retrospective cohort design evaluating Medicaid medical and pharmacy claims between January, 1996 and December, 2005 was employed for 11970 children and adolescents prescribed an antidepressant medication, and a random sample of 4500 children not treated with psychotropic medications. Incident obesity/weight gain, Type 2 diabetes mellitus, and dyslipidemia were more likely for those prescribed selective serotonin reuptake inhibitors (SSRIs) (OR = 1.49; 1.37; 1.44), whereas Type 2 diabetes mellitus and dyslipidemia were more likely for those prescribed weight-inducing antidepressants (ORs = 1.26; 1.24), and those with pre-existing endocrinopathies (ORs = 3.96; 1.90), controlling for the effects of co-prescribed mood stabilizers or antipsychotics. Incident nausea/vomiting was less likely for those taking SSRIs (OR = 0.78). Females and children under 12 years of age were more likely to develop these adverse effects. Practitioners need to carefully consider the neuroendocrine- related adverse effects of SSRI antidepressant agents in particular, especially in individuals with comorbid endocrine conditions, and those co-prescribed other classes of psychotropic medications.

Donepezil use in children and adolescents with tics and attention-deficit/hyperactivity disorder: an 18-week, single-center, dose-escalating, prospective, open-label study

BACKGROUND

Striatal cholinergic dysfunction may be important in tics and attention-deficit/hyperactivity disorder (ADHD).

OBJECTIVE

The purpose of this study was to determine the safety profile of donepezil and whether it improves chronic tics in young patients with comorbid ADHD.

METHODS

This 18-week (14 weeks of open treatment followed by a 4-week washout period), single-center, dose-escalating, prospective, open-label trial was conducted in patients aged 7 to 17 years with tics, including chronic motor or vocal tics and Tourette's syndrome, and ADHD. Patients were treated with once-daily oral donepezil doses of 2.5 mg for 2 weeks, 5 mg for the next 6 weeks, and 10 mg for the last 6 weeks, followed by a 4-week washout period. Patients were evaluated using the Children's Global Assessment Scale; the Yale Global Tic Severity Scale (YGTSS); the Revised Conners' Parent Rating Scale; the Symbol and Digit Wisconsin Card Sorting Test; the Stroop black/white, color, and interference tests; the Rey Complex Figure Test; and the Children's Yale-Brown Obsessive Compulsive Scale at 4 visits: baseline, week 8 (5-mg dose), week 14 (10-mg dose), and week 18 (washout).

RESULTS

Seventeen males and 3 females (mean [SD] age, 11.3 [1.9] years [range, 8-14 years]; tic duration, 5.3 [1.9] years; ADHD duration, 6.5 [1.7] years) were included in this study. Tics were significantly reduced at the 10-mg (week-14) donepezil visit compared with the baseline and washout visits based on the total mean (SD) tic score of the YGTSS (18.6 [9.3] vs 12.2 [11.0]; P = 0.006). Fifty percent of patients withdrew and 65% experienced adverse events.

CONCLUSIONS

These preliminary results suggest that donepezil significantly reduced tics in these children and adolescents with comorbid ADHD who completed the study. No significant improvement in the symptoms of comorbid ADHD was found with the use of donepezil 10 mg. Donepezil 5 and 10 mg were not well tolerated in these children and adolescents.

Focus on HTR2C: A possible suggestion for genetic studies of complex disorders

HTR2C is one of the most relevant and investigated serotonin receptors. Its role in important brain structures such as the midbrain, the lateral septal complex, the hypothalamus, the olfactory bulb, the pons, the choroid plexus, the nucleus pallidus, the striatum and the amygdala, the nucleus accumbens and the anterior cingulated gyrus candidate it as a promising target for genetic association studies. The biological relevance of these brain structures is reviewed by way of the focus on HTR2C activity, with a special attention paid to psychiatric disorders. Evidence from the genetic association studies that dealt with HTR2C is reviewed and discussed alongside the findings derived from the neuronatmic investigations. The reasons for the discrepancies between these two sets of reports are discussed. As a result, HTR2C is shown to play a pivotal role in many different psychiatric behaviors or psychiatric related disrupted molecular balances, nevertheless, genetic association studies brought inconsistent results so far. The most replicated association involve the feeding behavior and antipsychotic induced side effects, both weight gain and motor related: Cys23Ser (rs6318) and -759C/T (rs3813929) report the most consistent results. The lack of association found in other independent studies dampens the clinical impact of these reports. Here, we report a possible explanation for discrepant findings that is poorly or not at all usually considered, that is that HTR2C may exert different or even opposite activities in the brain depending on the structure analyzed and that mRNA editing activity may compensate possible genetically controlled functional effects. The incomplete coverage of the HTR2C variants is proposed as the best cost-benefit ratio bias to fix. The evidence of brain area specific HTR2C mRNA editing opens a debate about how the brain can differently modulate stress events, and process antidepressant treatments, in different brain areas. The mRNA editing activity on HTR2C may play a major role for the negative association results.

Hyperprolactinemia-related adverse events associated with antipsychotic treatment in children and adolescents

PURPOSE

To characterize factors related to the development of hyperprolactinemia and the ensuing reproductive/sexual adverse events in children and adolescents treated with antipsychotic and other psychotropic agents, and the additional risk posed for those with comorbid obesity, metabolic, or endocrine disorders.

METHODS

A retrospective cohort design evaluating medical and pharmacy claims from South Carolina's Medicaid program was used to compare incidence rates for sexual/reproductive adverse events in 4140 children and adolescents who were newly prescribed one of six atypical or two conventional antipsychotic medications, and a random sample of 4500 children not treated with psychotropic medications, January 1998 to December 2005. Logistic and Cox Proportional Hazards regression and Kaplan-Meier survival analysis were performed.

RESULTS

The treated cohort was not significantly more likely to evince hyperprolactinemia-related disorders than the control sample, but females and adolescents 13 and older were. Incident reproductive/sexual conditions were more likely for females (odds ratio [OR] = 9.52; confidence interval [CI] = 7.63-11.90), adolescents (OR = 3.91; CI = 3.25-4.70), those also taking selective serotonin reuptake inhibitors (SSRIs) (OR = 2.04; CI = 1.56-2.37) or valproic acid derivatives (OR = 1.29; CI = 1.03-1.64), and those with comorbid obesity/weight gain (OR = 1.92; CI = 1.56-2.37), metabolic (OR = 1.41; CI = 1.12-1.78), or endocrine disorders (OR = 2.76; CI = 1.98-3.84).

CONCLUSION

In this treated cohort, female adolescents exposed to SSRIs or valproic acid derivatives and those with comorbid obesity, metabolic, or endocrine disorders while taking antipsychotics were at higher risk of developing hyperprolactinemia and ensuing sexual/reproductive adverse events.

[Differences between men and women in side effects of second-generation antipsychotics]

In this review we investigate whether sex differences exist for side effects of second-generation antipsychotics. Results are based on a MEDLINE search for the years 1974 through 2005. Even if pharmacokinetics differ between females and males, significantly higher plasma levels for women have been demonstrated only for olanzapine and clozapine. Hyperprolactinaemia is mainly induced by treatment with risperidone and amisulpride, and there is evidence for more pronounced prolactin levels in females. Most studies reviewed indicate that clozapine and olanzapine are associated with more body weight gain, once more especially in female patients. Furthermore, the few published studies indicate that metabolic syndrome is more frequent in females and there are likely no gender-specific differences between the new antipsychotic medications concerning frequency and degree of acute or chronic movement disturbance. The risk of QT prolongation with torsades de pointes arrhythmia is again higher in females. In conclusion, there is some evidence of sex differences in the side effects of second-generation antipsychotics. For better understanding of the basic mechanisms in sex differences, future studies with a primary focus on this topic are required. More specific data will help to determine how these differences shall affect clinical management.

Potential bias in testing for hyperprolactinemia and pituitary tumors in risperidone-treated patients: a claims-based study

BACKGROUND

A reporting association of risperidone with pituitary tumors has been observed. Because such tumors are highly prevalent, there may be other reasons why they were revealed in association with risperidone treatment. We assessed two potential explanations: disproportionately more prolactin assessment and head/brain imaging in risperidone-treated patients vs patients treated with other antipsychotics.

METHODS

Treatment episodes with risperidone, clozapine, olanzapine, quetiapine, ziprasidone, aripiprazole, haloperidol, perphenazine and 'other typical' antipsychotics were identified in two databases (large commercial, Medicaid). Comparisons used proportional hazards regression to determine whether prolactin testing was disproportionate with risperidone, regardless of prior potentially prolactin-related adverse events (PPAEs). Logistic regression determined whether magnetic resonance imaging (MRI)/computed tomography (CT) were disproportionate in risperidone-treated patients vs other patients, regardless of hyperprolactinemia or PPAEs. In each regression, the 'other typical' antipsychotic category served as the comparator. Regression models controlled for age, gender, and other factors.

RESULTS

Altogether, 197,926 treatment episodes were analyzed (63,878 risperidone). Among patients with or without preceding PPAEs, risperidone treatment was associated with a significantly greater likelihood of prolactin assessment (hazard ratio (HR) 1.34, 95% confidence interval (CI) = 1.09 to 1.66, p = 0.007). Among patients with hyperprolactinemia or PPAEs, those treated with risperidone (odds ratio (OR) 1.66, 95% CI 1.23 to 2.23, p = 0.001) or ziprasidone (OR 1.66, 95% CI 1.06 to 2.62, p = 0.028) had a higher likelihood of MRI/CT.

CONCLUSION

Risperidone-treated patients are more likely to undergo prolactin assessment regardless of prior PPAEs, and more likely to undergo MRI/CT in association with hyperprolactinemia or PPAEs. Thus, a predisposition for more evaluations in risperidone-treated patients may contribute to disproportionate identification and reporting of prevalent pituitary adenoma.

Prolactin, subjective well-being and sexual dysfunction: an open label observational study comparing quetiapine with risperidone

INTRODUCTION

Sexual dysfunction is a frequent side effect of antipsychotic treatment. Increased prolactin levels are believed to be responsible for this sexual impairment despite contradictory results.

AIM

The primary objective of the present study was to examine the relationship between sexual dysfunction, subjective well-being and prolactin levels in patients with schizophrenia treated either with risperidone or quetiapine. The secondary objective was to explore the relationship between testosterone and the severity of positive and negative symptoms of schizophrenia in male patients.

METHODS

In a 4-week nonrandomized open label observational study, 102 inpatients with schizophrenia were recruited. Sexual functioning, subjective well-being and endocrinological parameters were assessed as well as psychopathological characteristics.

MAIN OUTCOME MEASURES

Two self-rating questionnaires concerned with sexual functioning ("Essener Fragebogen zur Sexualität") and Subjective Well-Being Under Neuroleptic Treatment Scale (SWN) were completed by the patients. Plasma levels of prolactin in male and female patients were measured. Furthermore, in male patients testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were determined. Positive and Negative Symptom Scale (PANSS) was applied.

RESULTS

After 4 weeks, patients treated with quetiapine reported less severe sexual impairment, as well as lower PANSS negative and general score compared with patients treated with risperidone. Additionally, emotional regulation as measured with the SWN was higher in patients treated with quetiapine. Risperidone was significantly associated with elevated prolactin levels. Prolactin levels were not correlated either with sexual dysfunction or PANSS. However, in the group of patients treated risperidone, sexual impairment was significantly associated with the SWN subscale emotional regulation.

CONCLUSIONS

Increased prolactin levels do not seem to be decisive for antipsychotic induced sexual dysfunction. Improvement of severity of illness and regaining the ability to regulate one's own emotion have positive influence on sexual functioning.

Clinical implications of antipsychotic-induced hyperprolactinemia in patients with schizophrenia spectrum or bipolar spectrum disorders: recent developments and current perspectives

Hyperprolactinemia is increasingly studied as a frequent and potentially important consequence of antipsychotic medication treatment. Some individuals presenting with hyperprolactinemia remain asymptomatic, but others may exhibit a wide range of clinical symptoms resulting from either the direct effects of prolactin on body tissues (galactorrhea, gynecomastia) or endocrine-related secondary effects (sexual and reproductive dysfunction in the short term, and possibly the risk of tumorigenesis and osteoporosis in the longer term). Short-term side effects may negatively impact medication compliance, and long-term effects have the potential for serious health consequences. Antipsychotic medications have differing propensities to cause prolactin elevation. The first-generation antipsychotics, as well as the second-generation antipsychotic risperidone and its active metabolite paliperidone, have been shown to cause marked and sustained elevations in prolactin levels, whereas others of the second-generation antipsychotics appear to have little or no effect on prolactin levels or may decrease prolactin. A comprehensive overview of antipsychotics and hyperprolactinemia is presented together with a review of emerging evidence about the short- and long-term health risks of hyperprolactinemia.

Low dose quetiapine induced galactorrhoea: a case report

BACKGROUND

Quetiapine causes less prolactin elevation and/or galactorrhoea than other atypical antipsychotics.

CASE PRESENTATION

Ms AB had galactorrhoea and raised prolactin levels at only 100 mg of quetiapine daily.

CONCLUSION

Low dose quetiapine can also cause galactorrhoea.

A naturalistic, 9-month follow-up, comparing olanzapine and conventional antipsychotics on sexual function and hormonal profile for males with schizophrenia

Second generation antipsychotics have less influence on prolactin levels than conventional antipsychotics (CA), which are commonly associated with sexual dysfunction and hyperprolactinaemia. However, only a few studies have been conducted assessing these newer antipsychotics and sexual function/dysfunction. The aim of this study is to evaluate the sexual function and hormonal profile of male schizophrenic patients taking olanzapine or CA. Sixty-three inpatients with acute episodes of schizophrenia were randomly assigned to take either olanzapine, or go on conventional antipsychotic treatment. The Dickson-Glazer sexual functioning questionnaire was used to assess sexual functioning where serum prolactin, luteinizing hormone, follicle-stimulating hormone, total testosterone, free testosterone, and sex hormone-binding globulin concentrations were measured. All measurements were taken on discharge from the inpatient unit (baseline), and again at 3 and 9 months after discharge. Prolactin levels in the olanzapine group decreased more rapidly and were significantly lower than in the CA group after 3 months (12.1+/-6.3 microg/l, p=0.01; 18.1+/-11.2 microg/l, p=0.564, respectively). After nine months, there was a tendency toward normal levels in both groups, and the frequency of sexual complaints did not differ between the groups. This study showed no difference between olanzapine and conventional antipsychotics regarding sexual complaints in the treatment of schizophrenia, but did show a difference in the hormone level normalization rate.

Partial compliance with antipsychotics and its impact on patient outcomes

Partial compliance with antipsychotic medications is a common and complex phenomenon that is underestimated by physicians. The consequences of partial compliance include an increased risk of relapse, rehospitalization and suicide attempts. Stigma, negative attitudes towards medications, cognitive impairment and diminished insight negatively impact treatment adherence. Oral atypical antipsychotics may improve both insight and cognitive function, but compliance with these agents is not assured. Depot conventional antipsychotics ensure medication delivery but are associated with side-effects such as EPS and dysphoria that decrease compliance. Long-acting atypicals provide significant symptom improvement, foster adherence and may help achieve improvement in insight and cognition. Addressing issues of partial and non-compliance is a significant consideration in relapse prevention strategies for patients with schizophrenia, given the devastating consequences associated with psychotic relapses.

Second-generation antipsychotics: is there evidence for sex differences in pharmacokinetic and adverse effect profiles?

Six second-generation antipsychotics (SGAs), aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone, are currently US FDA approved. The aim of this review is to investigate whether sex differences exist for efficacy and adverse effects of these drugs.Sex-related differences have been shown in the pharmacokinetics of cytochrome P450 (CYP), with a higher activity in females for CYP3A4 and CYP2D6. However, even if there are pharmacokinetic differences between females and males, significantly higher plasma concentrations in women have been demonstrated only for olanzapine and clozapine. To date, sex differences in adverse effects have not been well studied, but some adverse effects such as weight gain, hyperprolactinaemia and cardiac effects are reported to be particularly problematic for women. Most of the studies reviewed indicate that clozapine and olanzapine are associated with greater bodyweight gain than the other atypical antipsychotics, and that serious adverse effects such as metabolic syndrome, which includes increased visceral adiposity, hyperglycaemia, hypertension and dyslipidaemia induced by SGAs, are more frequent in females. According to most studies, the risk for cardiac adverse effects induced by SGAs is the same in male and female patients. Although women are at a lower risk of sudden cardiac death, they have a higher risk of induced long QT syndrome from antiarrhythmic and, probably, antipsychotic drugs. The propensity of sexual dysfunctions is higher with conventional antipsychotics than with SGAs. Additionally, there is some evidence that female sexual dysfunction is associated with high prolactin levels; however, whether the degree of prolactin level elevation is different between female and male patients remains controversial. There is no evidence for sex differences for any of the SGAs to cause a higher rate of extrapyramidal symptoms, acute dystonia or any other movement disturbance. Knowledge of the risks and benefits associated with the use of SGAs during pregnancy and lactation is limited, although the direction of dose adjustments during pregnancy depends on the drug and the enzyme that is responsible for its metabolism. In general, data on sex differences were mostly obtained by posthoc analysis and, therefore, the conclusions that can be drawn are limited. For a better understanding of the basic mechanisms of sex differences, future studies with a primary focus on this topic are required. Data that are more specific will help determine the extent to which these differences will have implications for clinical management.

Drug Insight: prolactin-receptor antagonists, a novel approach to treatment of unresolved systemic and local hyperprolactinemia?

Prolactin is a polypeptide hormone whose major biological actions are related to normal lactation and reproduction. Abnormally high prolactin levels, referred to as hyperprolactinemia, can result in various reproductive disorders. Currently, therapeutic management of hyperprolactinemia relies on dopamine agonists, since dopamine is the primary physiological suppressor of pituitary prolactin production. Epidemiologic studies have shown that prolactin levels in the high-normal range, as well as medications that interfere with dopamine action (e.g. certain antipsychotic drugs), might correlate with increased breast cancer risk. In addition to circulating prolactin, it is now well established that prolactin is also produced locally within various tissues, including breast and prostate. Increasing evidence, mainly from animal studies at present, suggests that excess locally produced prolactin may promote the growth of breast and prostate tumors via an autocrine or paracrine mechanism. These findings have renewed the interest in finding alternative strategies to suppress prolactin actions when dopamine agonists are ineffective. Our studies of the relationship between prolactin structure and function have resulted in the development of pure prolactin-receptor antagonists. These molecules prevent endogenous prolactin from exerting its actions via a competitive mechanism for receptor binding. In this review, we discuss the possible future therapeutic utility of this novel class of compounds.

Adverse extrapyramidal effects in four horse given fluphenazine decanoate

CASE DESCRIPTION

4 racehorses were examined because of markedly abnormal behavior following administration of fluphenazine decanoate.

CLINICAL FINDINGS

Clinical signs included restlessness, agitation, profuse sweating, hypermetria, aimless circling, intense pawing and striking with the thoracic limbs, and rhythmic swinging of the head and neck alternating with episodes of severe stupor. Fluphenazine was detected in serum or plasma from all 4 horses. The dose of fluphenazine decanoate administered to 3 of the 4 horses was within the range (25 to 50 mg) routinely administered to adult humans.

TREATMENT AND OUTCOME

In 2 horses, there was no response to IV administration of diphenhydramine hydrochloride, but the abnormal behavior in these 2 horses appeared to resolve following administration of benztropine mesylate, and both horses returned to racing. The other 2 horses responded to diphenhydramine administration. One returned to racing. The other was euthanized because of severe neurologic signs, respiratory failure, and acute renal failure.

CLINICAL RELEVANCE

Findings indicate that adverse extrapyramidal effects may occur in horses given fluphenazine decanoate. These effects appear to be unpredictable and may be severe and life threatening. Use of fluphenazine decanoate as an anxiolytic in performance horses is not permitted in many racing and horse show jurisdictions, and analytic procedures are now available to detect the presence of fluphenazine in serum or plasma.

Using aripiprazole to resolve antipsychotic-induced symptomatic hyperprolactinemia: a pilot study

OBJECTIVE

To assess the effectiveness of substituting aripiprazole for other antipsychotic drugs taken by stable schizophrenic patients suffering from antipsychotic agent-induced symptomatic hyperprolactinemia.

METHODS

Seven female schizophrenic patients with symptomatic hyperprolactinemia (167.6+/-58.0 microg/L) were recruited to take part in an 8-week open label trial of aripiprazole (10-20 mg/day) as a replacement for amisulpride or risperidone. Efficacy was assessed via PANSS and CGI-I scores. Serum prolactin levels were measured at baseline, week 4, and week 8. Data were collected from November, 2004 to May, 2005.

RESULTS

At the end of weeks 4, serum prolactin levels were normalized (8.8+/-5.5 microg/L) and hyperprolactinemic symptoms were resolved in all patients. However, aripiprazole treatment was discontinued within 6 weeks for 2 of the 7 subjects due to aggravated auditory hallucinations.

CONCLUSION

Results from this admittedly small-scale open-label study indicate that switching to aripiprazole may be useful for resolving antipsychotic-induced hyperprolactinemia and associated symptoms.

Review of evidence that posttransplantation psychiatric treatment commonly affects prolactin levels and thereby influences graft fate

Delirium, depression and other psychiatric difficulties are commonly encountered by posttransplantation patients, and antipsychotic medicines are frequently used to treat these difficulties. This article reviews previous research data concerning the immunological effects of these medicines, with particular focus on the consequences of prolactin elevation. Unproven but of concern is that these effects may influence graft fate. Older antipsychotic medicines such as haloperidol and chlorpromazine have a high likelihood of elevating prolactin. Prolactin is an immunologically active molecule generally promoting bone marrow function. This may be of benefit post-stem-cell transplant, helping engraftment, but could further rejection of solid-organ transplants. Elevated prolactin is implicated in the facilitation of graft-versus-host disease. Aripiprazole is the antipsychotic medicine least likely to increase prolactin (and may actually decrease prolactin); risperidone, the most likely to increase prolactin. Olanzapine, quetiapine and ziprazadone are antipsychotic medicines with a lower likelihood of elevating prolactin. Older ("neuroleptic") antipsychotics, such as chlorpromazine, droperidol and haloperidol, perphenazine and many others, are likely to elevate serum prolactin. Among antidepressants, most serotonin reuptake inhibitors, with the exception of sertraline, can slightly elevate prolactin. The atypical (i.e., alone in their class) antidepressants bupropion and mirtazapine are prolactin neutral. The immunological consequences of psychiatric medicines should be considered when treating transplant patients for delirium, depression and thought disorders; in addition, if elevation of prolactin is thought to be of immunological importance during psychiatric treatment, then it should be monitored and treated. The dopamine agonists used to treat Parkinson's disease--bromocriptine, pergolide, pramipexole, ropinerole--usually reverse antipsychotic-induced prolactin increases without compromising psychiatric effectiveness.

Risperidone: a review

When the risk of agranulocytosis associated with clozapine, the prototype of the second-generation neuroleptics, became apparent, its prescription was restricted to patients refractory to classical neuroleptics such as chlorpromazine and haloperidol. This stimulated the development of several novel second-generation antipsychotics with a clinical profile similar to that of clozapine. These novel antipsychotics, which include risperidone, olanzapine and others, are characterised by different pharmacological structures, and also to a certain degree by different pharmacological mechanisms. Following the increased research on the novel second-generation antipsychotics, it became apparent that they not only have the advantage of better extrapyramidal tolerability than the classical neuroleptics, but also have a broader efficacy spectrum (i.e., advantages in the treatment of negative and depressive symptoms and cognitive disturbances in the context of schizophrenia). Risperidone was specifically designed by Paul Janssen as a combined 5-HT2A and D2 receptor antagonist, thus following the pharmacological mechanism thought to be responsible for the antipsychotic effects of clozapine. After its advent in the 1990s as the first novel second-generation antipsychotic, risperidone achieved worldwide acceptance. The following review gives an overview of the huge clinical database available for risperidone in the field of schizophrenia.

The atypical antipsychotics olanzapine and quetiapine, but not haloperidol, reduce ACTH and cortisol secretion in healthy subjects

RATIONALE

Increased activity of the hypothalamic-pituitary-adrenal (HPA) axis is an important aspect of the pathophysiology of major depression and schizophrenia. Despite the usefulness of atypical antipsychotics in the treatment of depression and their positive influence on cognitive functioning possibly related to their impact on cortisol, little is known about their effect on HPA axis function.

OBJECTIVE

Therefore, this double-blind, placebo-controlled, randomized cross-over study investigated the influence of the atypical antipsychotics quetiapine and olanzapine in comparison with haloperidol and placebo on plasma adrenocorticotropic hormone (ACTH), cortisol, and prolactin levels. Eleven healthy male volunteers were studied during four sessions one week apart, orally receiving placebo, quetiapine (50 mg), olanzapine (5 mg), or haloperidol (3 mg). Blood samples were taken at hourly intervals from 0900 until 1700 hours. For ACTH, cortisol, and prolactin a significant effect of treatment condition (p < or = 0.005; p < or = 0.035; p < or = 0.0001, respectively) for area under the curve (AUC) was found. In comparison to placebo, quetiapine and olanzapine significantly reduced ACTH (p < or = 0.002; p < or = 0.05, respectively) and cortisol (p < or = 0.005; p < or = 0.03, respectively). No effect of haloperidol on AUC of ACTH or cortisol levels was observed. In comparison with placebo, haloperidol (p < or = 0.0001) and olanzapine (p < or = 0.0001) elevated AUC of prolactin plasma levels, whereas no significant effect was observed for quetiapine as a main effect of treatment condition. The atypical antipsychotics' strong influence on HPA-function with pronounced ACTH and cortisol lowering is possibly related to the atypicals' blockade of serotonergic receptors, but blockade of adrenergic or histaminergic receptors may play a role as well. The observed HPA-axis down-regulation may be clinically important for the atypicals' effects on depressive symptomatology and cognitive functioning.