Survey on the pharmacodynamics of the new antipsychotic risperidone

Using pharmacotherapy to address sleep disturbances in autism spectrum disorders

INTRODUCTION

Sleep disorders are the second most common medical comorbidity in autism spectrum disorder (ASD), with effects on daytime behavior and functioning, mood and anxiety, and autism core features. In children with ASD, insomnia also has a negative impact on the whole family's quality of life. Therefore, treatment of sleep disturbances should be considered as a primary goal in the management of ASD patients, and it is important to clarify the scientific evidence to inappropriate treatments.

AREAS COVERED

The authors review the current literature concerning the pharmacological treatment options for the management of sleep-related disorders in patients with ASD (aged 0-18 years) using the PubMed and Cochrane Library databases with the search terms: autism, autistic, autism spectrum disorder, ASD, drug, drug therapy, drug intervention, drug treatment, pharmacotherapy, pharmacological treatment, pharmacological therapy, pharmacological intervention, sleep, sleep disturbance, and sleep disorder.

EXPERT OPINION

Currently, clinicians tend to select medications for the treatment of sleep disorders in ASD based on the first-hand experience of psychiatrists and pediatricians as well as expert opinion. Nevertheless, at the present time, the only compound for which there is sufficient evidence is melatonin, although antihistamines, trazodone, clonidine, ramelteon, gabapentin, or suvorexant can also be considered for selection.

A systematic review on sex differences in adverse drug reactions related to psychotropic, cardiovascular, and analgesic medications

Background and objective: Adverse drug reactions (ADRs) are the main safety concerns of clinically used medications. Accumulating evidence has shown that ADRs can affect men and women differently, which suggests sex as a biological predictor in the risk of ADRs. This review aims to summarize the current state of knowledge on sex differences in ADRs with the focus on the commonly used psychotropic, cardiovascular, and analgesic medications, and to aid clinical decision making and future mechanistic investigations on this topic. Methods: PubMed search was performed with combinations of the following terms: over 1,800 drugs of interests, sex difference (and its related terms), and side effects (and its related terms), which yielded over 400 unique articles. Articles related to psychotropic, cardiovascular, and analgesic medications were included in the subsequent full-text review. Characteristics and the main findings (male-biased, female-biased, or not sex biased ADRs) of each included article were collected, and the results were summarized by drug class and/or individual drug. Results: Twenty-six articles studying sex differences in ADRs of six psychotropic medications, ten cardiovascular medications, and one analgesic medication were included in this review. The main findings of these articles suggested that more than half of the ADRs being evaluated showed sex difference pattern in occurrence rate. For instance, lithium was found to cause more thyroid dysfunction in women, and amisulpride induced prolactin increase was more pronounced in women than in men. Some serious ADRs were also found to exert sex difference pattern, such as clozapine induced neutropenia was more prevalent in women whereas simvastatin/atorvastatin-related abnormal liver functions were more pronounced in men.

Movement disorders and use of risperidone and methylphenidate: a review of case reports and an analysis of the WHO database in pharmacovigilance

For patients with attention deficit hyperactivity disorder and comorbid conduct-dissocial disorder, a combination therapy of the psychostimulant methylphenidate and the antipsychotic risperidone may be prescribed. Case reports describe the occurrence of movement disorders under this combination therapy, but clinical trials had limited power to detect these events. This study aimed (1) to summarise published case reports and (2) to analyse pharmacovigilance data consisting of adverse drug event reports to elucidate these reactions. PubMed, Embase, and APA PsycInfo were used to retrieve case reports. For the pharmacovigilance data, aggregated information on individual case safety reports (ICSRs) within the database of suspected adverse drug events by the WHO were analysed. ICSRs were assessed for disproportionality in reporting. Thirteen published case reports (62% male) on movement disorders were identified, with ages between 5 and 15 years. Seven reports (54%) described incidents when risperidone was tapered down or switched to methylphenidate. From the WHO, we identified 25,556 ICSRs (16,118 for methylphenidate, 8,614 for risperidone, and 824 for both). Of these, 953 (5.9%), 1356 (15.7%), and 159 (19.3%) ICSRs reported movement disorders in association with methylphenidate, risperidone or both, respectively. The analyses on disproportionality showed an increased number of ICSRs with movement disorders when the two drugs were coded in combination. The potential of movement disorders as adverse effects might be amplified when methylphenidate and risperidone are used in combination. The results from the literature underline the necessity of caution and patient monitoring when risperidone dosing is modified during methylphenidate therapy.

Anticonvulsant and antipsychotic medications in the pharmacotherapy of panic disorder: a structured review

BACKGROUND

As the remission rate of panic disorder (PD) achieved with conventional pharmacotherapy ranges between 20% and 50%, alternative psychopharmacological strategies are needed. We aimed to firstly review data regarding use of antipsychotic and non-benzodiazepine anticonvulsant medication in PD patients with or without comorbidities; secondly, to review data concerning reduction of panic symptoms during treatment of another psychiatric disorder with the same medications; and thirdly, to examine reports of anticonvulsant- or antipsychotic-induced new-onset panic symptomatology.

METHODS

We performed a PubMed search (last day: 28 April 2020) of English-language studies only, combining psychopathological terms (e.g. 'panic disorder') and terms referring either to categories of psychotropic medications (e.g. 'anticonvulsants') or to specific drugs (e.g. 'carbamazepine'). All duplications were eliminated. All studies included in the review met certain inclusion/exclusion criteria. The level of evidence for the efficacy of each drug was defined according to widely accepted criteria.

RESULTS

In treatment-resistant PD, beneficial effects have been reported after treatment (mostly augmentation therapy) with a range of anticonvulsant (carbamazepine, gabapentin, lamotrigine, levetiracetam, oxcarbamazepine, valproate, vigabatrin, tiagabine) and antipsychotic (aripiprazole, olanzapine, risperidone, sulpiride) medications: overall, most medications appear generally well tolerated. Additionally, bipolar patients receiving valproate or quetiapine-XR (but not risperidone or ziprasidone) demonstrated reductions of comorbid panic-related symptoms. There are case reports of new-onset panic symptoms associated with clozapine, haloperidol, olanzapine and topiramate, in patients with conditions other than PD. The small-to-modest sample size, the lack of control groups and the open-label and short-term nature of most of the reviewed studies hinder definitive conclusions regarding either the short-term and long-term efficacy of antipsychotic and anticonvulsant medications or their potential long-term side effects.

CONCLUSION

Some atypical antipsychotic and anticonvulsant medications may have a role in the treatment of some PD patients, mostly when more conventional approaches have not been successful, but the quality of supporting evidence is limited.

Prescribed drugs containing nitrogen heterocycles: an overview

Heteroatoms as well as heterocyclic scaffolds are frequently present as the common cores in a plethora of active pharmaceuticals natural products. Statistically, more than 85% of all biologically active compounds are heterocycles or comprise a heterocycle and most frequently, nitrogen heterocycles as a backbone in their complex structures. These facts disclose and emphasize the vital role of heterocycles in modern drug design and drug discovery. In this review, we try to present a comprehensive overview of top prescribed drugs containing nitrogen heterocycles, describing their pharmacological properties, medical applications and their selected synthetic pathways. It is worth mentioning that the reported examples are actually limited to current top selling drugs, being or containing N-heterocycles and their synthetic information has been extracted from both scientific journals and the wider patent literature.

Dose-Corrected Serum Concentrations and Metabolite to Parent Compound Ratios of Venlafaxine and Risperidone from Childhood to Old Age

OBJECTIVE

Comparative pharmacokinetic data about the antidepressant venlafaxine (VEN) and the antipsychotic drug risperidone (RIS) over the lifespan and especially in children and adolescents is lacking. This is the first cross-sectional study that aimed to investigate differences in dose-corrected serum concentrations (CDs) and metabolite to parent compound ratios (MPRs) of VEN and RIS across the lifespan.

METHODS

Patients treated with VEN and RIS at the University Hospital of Würzburg, Germany were included in the study. Serum level determinations were performed during clinical routine care. Patients with CYP2D6 influencing co-medication were excluded from analyses.

RESULTS

In 953 patients (12-93 years) treated with VEN and 552 patients (7-92 years) treated with RIS, children/adolescents (<18 years) showed 11% and 19%, and 44% and 42% lower CDs of the active moieties (CDs_AM) of VEN and RIS than adults and elderly (≥60 years) (Kruskal-Wallis tests; p ≤ 0.001). However, when CDs were normalized to body weight, a different pattern emerged. Gender differences, with higher CDs_AM in females were present in adults and elderlies but not in children/adolescents. No gender- or age-dependent difference in MPRs was found; however, 80% of MPRs of RIS in children/adolescents were below the range of "normal" CYP2D6 function for adults.

CONCLUSIONS

We suggest a higher clearance as a reason for lower CDs_AM of VEN and RIS in children/adolescents compared to adults/elderlies. Metabolism of VEN or RIS by CYP2D6, characterized by MPRs, was not associated with age. However, MPRs of RIS were lower in children/adolescents, possibly due to a higher renal clearance of 9-OH-risperidone.

Designed proteinoid polymers and nanoparticles encapsulating risperidone for enhanced antipsychotic activity

BACKGROUND

Nanoparticles (NPs) incorporating drug formulations can be used to facilitate passage through biological barriers including the blood-brain barrier (BBB) and increase drug delivery and bioavailability. Hence, NP-based administration may enhance the efficiency of current antipsychotics. Encapsulation within NPs can resolve aqueous solubility problems that not only reduce permeability through the BBB but also affect targeting. The present study describes a new drug delivery system based on proteinoid NPs to explore the possibility of improving drug efficacy. Risperidone (RSP) is a commonly used atypical antipsychotic medication, and was therefore selected for encapsulation by proteinoid NPs.

RESULTS

Proteinoid polymers with high molecular weight and low polydispersity were synthesized from L-amino acids and poly-L-lactic acid (PLLA) by thermal step-growth polymerization mechanism. RSP-loaded proteinoid NPs were then prepared using a self-assembly process in the presence of RSP, followed by PEGylation. The optimal PEGylated RSP-loaded NPs were characterized in terms of diameter and size distribution, drug loading, ζ-potential, cytotoxicity, biodistribution, and psychopharmacological effects. The findings indicate significantly higher antipsychotic activity of drug-loaded proteinoid NPs compared to free RSP.

CONCLUSIONS

Proteinoid NPs enhance RSP delivery and may potentially increase drug efficiency by reducing dosage and side effects.

Proteinoid Nanocapsules as Drug Delivery System for Improving Antipsychotic Activity of Risperidone

Risperidone (RSP) is an atypical antipsychotic drug widely used to treat schizophrenia and bipolar disorder. Nanoparticles (NPs) are being developed as in vivo targeted drug delivery systems, which cross the blood-brain barrier and improve pharmacokinetics and drug effectiveness. Here, biodegradable proteinoids were synthesized by thermal step-growth polymerization from the amino acids l-glutamic acid, l-phenylalanine and l-histidine and poly (l-lactic acid). Proteinoid NPs containing RSP were then formed by self-assembly, overcoming the insolubility of the drug in water, followed by PEGylation (poly ethylene glycol (PEG) conjugation to increase the stability of the NPs in the aqueous continuous phase. These NPs are biodegradable owing to their peptide and ester moieties. They were characterized in terms of diameter, size distribution, drug loading, and long-term storage. Behavioral studies on mice found enhanced antipsychotic activity compared to free RSP.

Preclinical validation of the micropipette-guided drug administration (MDA) method in the maternal immune activation model of neurodevelopmental disorders

Pharmacological treatments in laboratory rodents remain a cornerstone of preclinical psychopharmacological research and drug development. There are numerous ways in which acute or chronic pharmacological treatments can be implemented, with each method having certain advantages and drawbacks. Here, we describe and validate a novel treatment method in mice, which we refer to as the micropipette-guided drug administration (MDA) procedure. This administration method is based on a sweetened condensed milk solution as a vehicle for pharmacological substances, which motivates the animals to consume vehicle and/or drug solutions voluntarily in the presence of the experimenter. In a proof-of-concept study, we show that the pharmacokinetic profiles of the atypical antipsychotic drug, risperidone, were similar whether administered via the MDA procedure or via the conventional oral gavage method. Unlike the latter, however, MDA did not induce the stress hormone, corticosterone. Furthermore, we assessed the suitability and validity of the MDA method in a mouse model of maternal immune activation, which is frequently used as a model of immune-mediated neurodevelopmental disorders. Using this model, we found that chronic treatment (>4 weeks, once per day) with risperidone via MDA led to a dose-dependent mitigation of MIA-induced social interaction deficits and amphetamine hypersensitivity. Taken together, the MDA procedure described herein represents a novel pharmacological administration method for per os treatments in mice that is easy to implement, cost effective, non-invasive, and less stressful for the animals than conventional oral gavage methods.

Physiologically Based Pharmacokinetic Modeling to Understand the Absorption of Risperidone Orodispersible Film

Objective

The aim of the present study was to investigate the absorption routes as well as the potential application of the oral transmucosal delivery of risperidone orodispersible film (ODF) using physiologically based pharmacokinetic modeling.

Methods

The pharmacokinetic study after intragastric (i.g.), supralingual, and sublingual administration of risperidone ODF was conducted in Beagle dogs. Then a mechanic absorption model which combined Oral Cavity Compartment Absorption and Transit (OCCAT) model with Advanced Compartment Absorption and Transit (ACAT) model for predicting the absorption routes of risperidone ODF in vivo was constructed using GastroPlus™. A sensitivity analysis was performed to investigate the impact of oral residence time on the in vivo absorption of risperidone ODF. Based on the fraction of intraoral absorption, the potential of the oral transmucosal delivery of risperidone were predicted.

Results

There were no statistical differences in the AUC_0-t (P = 0.4327), AUC_0-∞ (P = 0.3278), C_max (P = 0.0531), and T_max (P = 0.2775) values among i.g., supralingual, and sublingual administration of risperidone ODF in Beagle dogs. The predicted absorption percentage via oral mucosa at oral residence time of 2 min, 5 min, and 10 min was 7.0%, 11.4%, and 19.5%, respectively. No obvious difference was observed for the bioavailability of risperidone ODF within 10 min of oral residence time. The PBPK absorption model for risperidone could be simplified to include ACAT model solely.

Conclusion

The main absorption route for risperidone ODF was the gastrointestine. The absorption percentage via oral mucosa was almost negligible due to the physicochemical properties of risperidone although ODF dissolved completely in the oral cavity of Beagle dogs within 2 min.

Structural insight into the serotonin (5-HT) receptor family by molecular docking, molecular dynamics simulation and systems pharmacology analysis

Serotonin (5-HT) receptors are proteins involved in various neurological and biological processes, such as aggression, anxiety, appetite, cognition, learning, memory, mood, sleep, and thermoregulation. They are commonly associated with drug abuse and addiction due to their importance as targets for various pharmaceutical and recreational drugs. However, due to a high sequence similarity/identity among 5-HT receptors and the unavailability of the 3D structure of the different 5-HT receptor, no report was available so far regarding the systematical comparison of the key and selective residues involved in the binding pocket, making it difficult to design subtype-selective serotonergic drugs. In this work, we first built and validated three-dimensional models for all 5-HT receptors based on the existing crystal structures of 5-HT_1B, 5-HT_2B, and 5-HT_2C. Then, we performed molecular docking studies between 5-HT receptors agonists/inhibitors and our 3D models. The results from docking were consistent with the known binding affinities of each model. Sequentially, we compared the binding pose and selective residues among 5-HT receptors. Our results showed that the affinity variation could be potentially attributed to the selective residues located in the binding pockets. Moreover, we performed MD simulations for 12 5-HT receptors complexed with ligands; the results were consistent with our docking results and the reported data. Finally, we carried out off-target prediction and blood-brain barrier (BBB) prediction for Captagon using our established hallucinogen-related chemogenomics knowledgebase and in-house computational tools, with the hope to provide more information regarding the use of Captagon. We showed that 5-HT_2C, 5-HT_5A, and 5-HT₇ were the most promising targets for Captagon before metabolism. Overall, our findings can provide insights into future drug discovery and design of medications with high specificity to the individual 5-HT receptor to decrease the risk of addiction and prevent drug abuse.

THE METABOLIC SYNDROME IN OUTPATIENTS WITH PSYCHOSIS: A COMPARATIVE STUDY BETWEEN LONG ACTING INJECTABLE OLANZAPINE AND RISPERIDONE

CONTEXT

Literature shows that patients taking antipsychotic medication risk developing metabolic complications.

OBJECTIVE

The study aims to compare the presence of the metabolic syndrome (MS) and its components in outpatients treated with long acting injectable (LAI) olanzapine and risperidone.

DESIGN

A double-center study was performed on outpatients with psychosis, which were divided into two samples: one treated with olanzapine and another with risperidone.

SUBJECTS AND METHODS

The following data were analyzed: age, gender, severity of psychiatric symptoms, blood pressure, waist circumference, fasting blood glucose, lipid profile, tobacco use, medication, and time intervals related to psychosis duration (pre-LAI and LAI treatment).

RESULTS

The study included 77 patients with schizophrenia and schizoaffective disorder. MS was present in 45 (58.4%) patients. Subjects with MS and abdominal obesity had higher durations of psychosis and of LAI treatment. Patients with hypertension had a higher pre-LAI treatment interval. Risperidone was associated with higher rates of hypertension and higher values of abdominal circumference than olanzapine.

CONCLUSIONS

The presence of MS is related to the duration of the psychosis and the time spent on LAI treatment with no differences between olanzapine and risperidone. Hypertension may be a consequence of age, disorder induced stress, or of treatment with risperidone.

Risperidone as an effective choice for obsessive-compulsive symptoms and tardive dyskinesia in an Indian quadragenarian with schizo-obsessive disorder

Tardive dyskinesia (TD) is a chronic, stigmatizing side effect of typical and atypical antipsychotics that is often debilitating for the patient and resistant to treatment. Obsessive-compulsive symptoms (OCS) may arise at any stage of schizophrenia ranging from prodrome to posttreatment and carry a poor prognosis. Management of both the conditions is a challenging and often fatiguing task for the treating physician. We report a case of schizo-obsessive disorder in an Indian quadragenarian who had developed TD with olanzapine and had failed to show improvement with clozapine and quetiapine. The patient improved dramatically with risperidone. Our findings corroborate with previous literature which has shown risperidone to be effective in treatment of TD and obsessive symptoms, possibly due to its action on the serotonergic system. The authors conclude that risperidone is an effective choice to treat TD and comorbid OCS in patients with schizophrenia.

A novel approach to cardiovascular disturbances in patients with schizophrenia spectrum disorders treated with long-acting injectable medication

PURPOSE

This research article assesses the cardiovascular impact of long-term injectable antipsychotic therapy on patients diagnosed with schizophrenia spectrum disorders. In our study, we attempted to quantify the potential causes of cardiovascular damage, assess cardiovascular parameters, and correlate them with the time elapsed from the onset of the psychosis until the initiation of injectable antipsychotic therapy, as well as the duration of long-acting therapy, and finally, to compare two of the most utilized long-acting injectable (LAI) medications (olanzapine vs risperidone).

PATIENTS AND METHODS

This cross-sectional study recruited 64 patients of 2 outpatient clinics undergoing treatment with LAI antipsychotics for schizophrenic spectrum disorder. The study reports outpatients' clinical data, laboratory blood sample findings, routine echocardiography, as well as speckle tracking echocardiography.

RESULTS

Among patients with longer durations of pre-long-acting antipsychotic treatment, body mass indices, mitral velocity wave values (E and A waves), and the global longitudinal strain (GLS) measurements significantly correlated with patients' myocardial contractility. The study also found that GLS was significantly lower in the group in which pre-LAI duration was prolonged, and was not influenced by the duration of LAI treatment. Furthermore, patients receiving olanzapine showed significantly improved myocardial contractility as measured by the aforementioned parameters, in comparison with patients treated with risperidone.

CONCLUSION

The results of our study indicate that patients suffering from schizophrenia and who are left untreated or poorly treated for a longer period of time may develop myocardial impairment. The changes may be both secondary to a high prevalence of cardiovascular risk factors and may also be generated by the disease per se. The group who received olanzapine demonstrated improved results for a longer period of time without proper medication.

The affinity of antipsychotic drugs to dopamine and serotonin 5-HT2 receptors determines their effects on prefrontal-striatal functional connectivity

One of the major challenges of cross-species translation in psychiatry is the identification of quantifiable brain phenotypes linked to drug efficacy and/or side effects. A measure that has received increasing interest is the effect of antipsychotic drugs on resting-state functional connectivity (FC) in magnetic resonance imaging. However, quantitative comparisons of antipsychotic drug-induced alterations of FC patterns are missing. Consideration of receptor binding affinities provides a means for the effects of antipsychotic drugs on extended brain networks to be related directly to their molecular mechanism of action. Therefore, we examined the relationship between the affinities of three second-generation antipsychotics (amisulpride, risperidone and olanzapine) to dopamine and serotonin receptors and FC patterns related to the prefrontal cortex (PFC) and striatum in Sprague-Dawley rats. FC of the relevant regions was quantified by correlation coefficients and local network properties. Each drug group (32 animals per group) was subdivided into three dose groups and a vehicle control group. A linear relationship was discovered for the mid-dose of antipsychotic compounds, with stronger affinity to serotonin 5-HT_2A, 5-HT_2C and 5-HT_1A receptors and decreased affinity to D₃ receptors associated with increased prefrontal-striatal FC (p = 0.0004, r² = 0.46; p = 0.004, r² = 0.33; p = 0.002, r² = 0.37; p = 0.02, r² = 0.22, respectively). Interestingly, no correlation was observed for the low and high dose groups, and for D₂ receptors. Our results indicate that drug-induced FC patterns may be linked to antipsychotic mechanism of action on the molecular level and suggest the technique's value for drug development, especially if our results are extended to a larger number of antipsychotics.

A systematic review of the effects of CYP2D6 phenotypes on risperidone treatment in children and adolescents

The second generation antipsychotic drug risperidone is widely used in the field of child and adolescent psychiatry to treat conditions associated with disruptive behavior, aggression and irritability, such as autism spectrum disorders. While risperidone can provide symptomatic relief for many patients, there is considerable individual variability in the therapeutic response and side-effect profile of the medication. One well established biological factor that contributes to these individual differences is genetic variation in the cytochrome P450 enzyme 2D6. The 2D6 enzyme metabolizes risperidone and therefore affects drug levels and dosing. In the present review, we summarize the current literature on 2D6 variants and their effects on risperidone responses, specifically in children and adolescents. Relevant articles were identified through systematic review, and after irrelevant articles were discarded, ten studies were included in the review. Most prospective studies were well controlled, but often did not have a large enough sample size to make robust statements about rarer variants, including those categorized as ultra-rapid and poor metabolizers. Individual studies demonstrated a role for different genetic variants in risperidone drug efficacy, pharmacokinetics, hyperprolactinemia, weight gain, extrapyramidal symptoms and drug-drug interactions. Where studies overlapped in measurements, there was typically a consensus between results. These findings indicate that the value of 2D6 genotyping in the youth population treated with risperidone requires further study, in particular with the less common variants.

Risperidone for psychosis-induced aggression or agitation (rapid tranquillisation)

BACKGROUND

Aggressive, agitated or violent behaviour due to psychosis constitutes an emergency psychiatric treatment where fast-acting interventions are required. Risperidone is a widely accessible antipsychotic that can be used to manage psychosis-induced aggression or agitation.

OBJECTIVES

To examine whether oral risperidone alone is an effective treatment for psychosis-induced aggression or agitation.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials (up to April 2017); this register is compiled by systematic searches of major resources (including AMED, BIOSIS CINAHL, Embase, MEDLINE, PsycINFO, PubMed, and registries of clinical trials) and their monthly updates, handsearches, grey literature, and conference proceedings. There are no language, date, document type, or publication status limitations for inclusion of records into the register.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing rapid use of risperidone and other drugs, combinations of drugs or placebo for people exhibiting aggression or agitation (or both) thought to be due to psychosis.

DATA COLLECTION AND ANALYSIS

We independently inspected all citations from searches, identified relevant abstracts, and independently extracted data from all included studies. For binary data we calculated risk ratio (RR) and for continuous data we calculated mean difference (MD), all with 95% confidence intervals (CI) and used a fixed-effect model. We assessed risk of bias for the included studies and used the GRADE approach to produce a 'Summary of findings' tables.

MAIN RESULTS

The review now contains data from nine trials (total n = 582) reporting on five comparisons. Due to risk of bias, small size of trials, indirectness of outcome measures and a paucity of investigated and reported 'pragmatic' outcomes, evidence was graded as very-low quality. None of the included studies provided useable data on our primary outcome 'tranquillisation or asleep' by 30 minutes, repeated need for tranquillisation or any economic outcomes. Data were available for our other main outcomes of agitation or aggression, needing restraint, and incidence of adverse effects.Risperidone versus haloperidol (up to 24 hours follow-up)For the outcome, specific behaviour - agitation, no clear difference was found between risperidone and haloperidol in terms of efficacy, measured as at least 50% reduction in the Positive and Negative Syndrome Scale - Psychotic Agitation Sub-score (PANSS-PAS) (RR 1.04, 95% CI 0.86 to 1.26; participants = 124; studies = 1; very low-quality evidence) and no effect was observed for need to use restraints (RR 2.00, 95% CI 0.43 to 9.21; participants = 28; studies = 1; very low-quality evidence). Incidence of adverse effects was similar between treatment groups (RR 0.94, 95% CI 0.54 to 1.66; participants = 124; studies = 1; very low-quality evidence).Risperidone versus olanzapineOne small trial (n = 29) reported useable data for the comparison risperidone versus olanzapine. No effect was observed for agitation measured as PANSS-PAS endpoint score at two hours (MD 2.50, 95% CI -2.46 to 7.46; very low-quality evidence); need to use restraints at four days (RR 1.43, 95% CI 0.39 to 5.28; very-low quality evidence); specific movement disorders measured as Behavioural Activity Rating Scale (BARS) endpoint score at four days (MD 0.20, 95% CI -0.43 to 0.83; very low-quality evidence).Risperidone versus quetiapineOne trial reported (n = 40) useable data for the comparison risperidone versus quetiapine. Aggression was measured using the Modified Overt Aggression Scale (MOAS) endpoint score at two weeks. A clear difference, favouring quetiapine was observed (MD 1.80, 95% CI 0.20 to 3.40; very-low quality evidence). No evidence of a difference between treatment groups could be observed for incidence of akathisia after 24 hours (RR 1.67, 95% CI 0.46 to 6.06; very low-quality evidence). Two participants allocated to risperidone and one allocated to quetiapine experienced myocardial ischaemia during the trial.Risperidone versus risperidone + oxcarbazepineOne trial (n = 68) measured agitation using the Positive and Negative Syndrome Scale - Excited Component.(PANSS-EC) endpoint score and found a clear difference, favouring the combination treatment at one week (MD 2.70, 95% CI 0.42 to 4.98; very low-quality evidence), but no effect was observed for global state using Clinical Global Impression - Improvement (CGI-I) endpoint score at one week (MD -0.20, 95% CI -0.61 to 0.21; very-low quality evidence). Incidence of extrapyramidal symptoms after 24 hours was similar between treatment groups (RR 1.59, 95% CI 0.49 to 5.14; very-low quality evidence).Risperidone versus risperidone + valproic acidTwo trials compared risperidone with a combination of risperidone plus valproic acid. No clear differences between the treatment groups were observed for aggression (MOAS endpoint score at three days: MD 1.07, 95% CI -0.20 to 2.34; participants = 54; studies = 1; very low-quality evidence) or incidence of akathisia after 24 hours: RR 0.75, 95% CI 0.28 to 2.03; participants = 122; studies = 2; very low-quality evidence).

AUTHORS' CONCLUSIONS

Overall, results for the main outcomes show no real effect for risperidone. The only data available for use in this review are from nine under-sampled trials and the evidence available is of very low quality. This casts uncertainty on the role of risperidone in rapid tranquillisation for people with psychosis-induced aggression. High-quality pragmatic RCTs are feasible and are needed before clear recommendations can be drawn on the use of risperidone for psychosis-induced aggression or agitation.

Risperidone improves interpersonal perception and executive function in patients with schizophrenia

OBJECTIVE

To investigate whether risperidone improves social cognitive impairments and executive dysfunction in people with schizophrenia.

METHODS

Fifty-six patients who met the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, diagnostic criteria for schizophrenia were allocated to a risperidone treatment group (RTG, n=28) and a typical antipsychotic treatment group (TATG, n=28). Twenty-eight healthy volunteers were recruited as the normal control group (NCG). The Positive and Negative Syndrome Scale, Interpersonal Perception Task-15 (IPT-15), and Wisconsin Card Sorting Test (WCST) were rated at baseline and after 4 and 12 weeks of treatment with risperidone or typical antipsychotics.

RESULTS

Risperidone and typical antipsychotics decreased Positive and Negative Syndrome Scale scores for total psychopathology and positive and negative symptoms. At baseline, in the IPT-15, total scores and five factor scores, as well as the number of categories completed and the percentage of conceptual level responses, were significantly lower in the RTG and TATG than in the NCG, whereas total response errors, perseverative errors, and failure to maintain set were significantly higher in the patient groups than in the NCG. Repeated measures analysis of variance revealed a significant main effect of time period (baseline, 4 weeks, and 12 weeks) for IPT-15 scores and WCST performances, and significant interactions for time period × group (RTG and TATG). Multivariate analysis of variance showed no significant differences between the RTG and TATG on IPT-15 scores at 4 weeks, but there were significant differences between these two groups at 12 weeks. Significant differences were also found between the RTG and TATG on WCST performances at 4 and 12 weeks.

CONCLUSION

Individuals with schizophrenia have impairments in social cognitive and executive function, which might be improved by risperidone.

Comparative Pharmacology of Risperidone and Paliperidone

Antipsychotics, risperidone, and risperidone’s active metabolite, paliperidone (9-hydroxyrisperidone), are related molecules used for the treatment of schizophrenia and related disorders. Differences in receptor binding, 5-HT_2A/D₂ (serotonin/dopamine) binding ratios, and mitochondrial proteomics suggest that the effects of risperidone and paliperidone on neuronal firing, regulation of mitochondrial function, and movement are different. This review seeks to explore the most significant differences at the molecular level between risperidone and paliperidone, as reported in preclinical studies. Although risperidone shows higher affinity for 5-HT receptors, paliperidone does not fit this profile. Thus, the risperidone 5-HT_2A/D₂ binding ratio is significantly lower than the paliperidone 5-HT_2A/D₂ binding ratio. Paliperidone, similar to lithium and valproate, affects expression levels and phosphorylation of complex I and V proteins in synaptoneurosomal preparations of rat prefrontal cortex, suggesting that paliperidone behaves as a mood stabilizer. It is apparent that the presence of a hydroxyl group in the paliperidone molecule confers increased hydrophilicity to this drug compared with its parent, risperidone; thus, this contributes to differential effects on mitochondrial movement, protein expression, and phosphorylation. These differences are reflected in synaptic plasticity and neuronal firing and have only recently been implicated in the mechanisms of mitochondrial function and movement.

Sleep in Autism Spectrum Disorders

Autism spectrum disorders (ASD) are common neurodevelopmental conditions, affecting 1 in 68 children. Sleep disturbance, particularly insomnia, is very common in children diagnosed with ASD, with evidence supporting overlapping neurobiological and genetic underpinnings. Disturbed sleep exacerbates core and related ASD symptoms and has a substantial negative impact on the entire family. Treatment of sleep disturbance holds promise for ameliorating many of the challenging behavioral symptoms that children with ASD and their families face. Behavioral and pharmacological studies indicate promising approaches to treating sleep disturbances in this population. Awareness of treatment options is particularly important as parents and clinicians may believe that sleep disturbance is part of autism and refractory to therapy. In addition, autism symptoms refractory to treatment with conventional psychiatric medications may improve when sleep is addressed. Additional evidence-based studies are needed, including those that address the underlying biology of this condition.

Pharmacogenetics of second-generation antipsychotics

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

Regulation of neutrophil phagocytosis of Escherichia coli by antipsychotic drugs

Antipsychotic drugs (APDs) have been used to ease the symptoms of schizophrenia. APDs have recently been reported to regulate the immune response. Our previous studies revealed that the atypical APDs risperidone and clozapine and the typical APD haloperidol can inhibit the phagocytic ability of macrophages. Our research next determined the effects of APDs on the phagocytic ability of neutrophils, which are the most abundant type of white blood cells in mammals. Here we provide evidence that clozapine and haloperidol can induce increased phagocytic uptake of Escherichia coli by differentiated HL-60 cells and by purified human neutrophils. Furthermore, clozapine and haloperidol can increase the myeloperoxidase activity and IL-8 production in neutrophils. Our results also show that clozapine can inhibit E. coli survival within differentiated HL-60 cells. Furthermore, clozapine and haloperidol are shown to enhance cell surface Mac-1 expression and the activated AKT signaling pathway in purified neutrophils exposed to E. coli. These results indicate that clozapine and haloperidol can increase the phagocytic ability of neutrophils by increasing AKT activation when cells are exposed to bacteria.

Suppression of metastasis by mirtazapine via restoration of the Lin-7C/β-catenin pathway in human cancer cells

No definitive therapy exists to treat human metastatic tumors. We reported previously that down-regulation of Lin-7C is essential for metastasis of human squamous cell carcinomas (hSCCs). In this study, we investigated the chemical restoration of Lin-7C expression and demonstrated its effectiveness for suppressing the metastatic potential in human cancer cells. Ingenuity Pathway Analysis (IPA) identified candidate chemical agents, i.e., apomorphine, caffeine, risperidone, quetiapine, and mirtazapine. Among them, mirtazapine, an antagonist of HTR2C, an upstream molecule of Lin-7C, caused substantial up-regulation of the Lin-7C/β-catenin pathway in a metastatic hSCC cell line and human melanoma-derived cell line in vitro, and up-regulation did not contribute to cellular proliferation. Moreover, the antimetastatic effect of mirtazapine in these metastatic cell lines in vivo also was evident in multiple organs of immunodeficient mice with no marked side effects. The current data offer novel information for further study of antimetastatic activity in association with enhanced Lin-7C/β-catenin pathway activation with mirtazapine.

A 12-week subchronic intramuscular toxicity study of risperidone-loaded microspheres in rats

Long-acting injectable formulations of antipsychotics have been an important treatment option to increase the compliance of the patient with schizophrenia by monitoring drug administration and identifying medication noncompliance and to improve the long-term management of schizophrenia. Risperidone, a serotoninergic 5-HT2 and dopaminergic D2 receptor antagonist, was developed to be a long-acting sustained-release formulation for the treatment of schizophrenia. In this study, 12-week subchronic toxicity study of risperidone-loaded microspheres (RMs) in rats by intramuscular injection with an 8-week recovery phase was carried out to investigate the potential subchronic toxicity of a novel long-acting sustained-release formulation. The results indicated that the dosage of 10-90 mg/kg of RM for 2 weeks did not cause treatment-related mortality. The main drug-related findings were contributed to the dopamine D2 receptor and α1-adrenoceptor antagonism of risperidone such as elevation of serum and pituitary prolactin levels and ptosis and changes in reproductive system (uterus, ovary, vagina, mammary gland, testis, seminal vesicle, epididymis, and prostate). In addition, foreign body granuloma in muscle at injection sites caused by poly-lactide-co-glycolide was observed. At the end of the recovery phase, these changes mostly returned to normal. The results indicated that RM had a good safety profile in rats.

Changes in plasma concentrations of risperidone and 9-hydroxyrisperidone and the associated clinical effects during the switch from oral risperidone to extended-release paliperidone tablets in patients with schizophrenia

This study aimed to investigate changes in plasma concentrations of risperidone and 9-hydroxy-risperidone (9-OHR) and the associated clinical effects when switching from oral risperidone to extended-release (ER) paliperidone in patients with schizophrenia. This study included 25 patients with schizophrenia. Following a one-week screening period with a stable dose of risperidone, a six-week open-label switch study from risperidone to extended-release paliperidone (paliperidone ER) was conducted. Efficacy and safety assessments were performed on Day 1 and at Weeks 1, 2, 4, and 6. Plasma levels of the active fractions of oral risperidone and paliperidone ER were measured on Day 1 and at Week 1, respectively. Plasma levels of the active moiety (risperidone plus 9-OHR) while taking risperidone (mean dose: 4.0 mg) were significantly higher than plasma levels of 9-OHR while taking 6 mg of paliperidone ER. For 12 subjects taking only 3 mg of risperidone, plasma concentrations of the active moiety of risperidone were also significantly higher than those of 9-OHR while taking 6 mg of paliperidone ER. The amount of reduction in plasma levels was correlated with a temporal deterioration of clinical symptoms. These findings suggest that for patients with schizophrenia taking 3 mg or more of risperidone, an initial switching dose of 6 mg of paliperidone ER may be relatively low in terms of subsequent plasma concentrations and the associated clinical response.

One-pot multicomponent synthesis of highly functionalized piperidines from substituted β-nitrostyrenes, Meldrum's acid, aromatic aldehydes, and ammonium acetate

An efficient and straightforward synthetic protocol has been developed for the diversity-oriented synthesis of highly functionalized piperidines containing a Meldrum's acid moiety via pseudo five-component reaction between aromatic aldehydes, ammonium acetate, substituted β-nitrostyrenes and Meldrum's acid for the generation of a wide range of structurally interesting and pharmacologically significant compounds.

Neuroprotection of posttreatment with risperidone, an atypical antipsychotic drug, in rat and gerbil models of ischemic stroke and the maintenance of antioxidants in a gerbil model of ischemic stroke

Risperidone, an atypical antipsychotic drug, has been discovered to have some beneficial effects beyond its original effectiveness. The present study examines the neuroprotective effects of risperidone against ischemic damage in the rat and gerbil induced by transient focal and global cerebral ischemia, respectively. The results showed that pre- and posttreatment with 4 mg/kg risperidone significantly protected against neuronal death from ischemic injury. Many NeuN-immunoreactive neurons and a few F-J B-positive cells were found in the rat cerebral cortex and gerbil hippocampal CA1 region (CA1) in the risperidone-treated ischemia groups compared with those in the vehicle-treated ischemia group. In addition, treatment with risperidone markedly attenuated the activation of microglia in the gerbil CA1. On the other hand, we found that treatment with risperidone significantly maintained the antioxidants levels in the ischemic gerbil CA1. Immunoreactivities of superoxide dismutases 1 and 2, catalase, and glutathione peroxidase were maintained in the stratum pyramidale of the CA1; the antioxidants were very different from those in the vehicle-treated ischemia groups. In brief, our present findings indicate that posttreatment as well as pretreatment with risperidone can protect neurons in the rat cerebral cortex and gerbils CA1 from transient cerebral ischemic injury and that the neuroprotective effect of risperidone may be related to attenuation of microglial activation as well as maintenance of antioxidants.

Development of Risperidone PLGA Microspheres

The aim of this study was to design and evaluate biodegradable PLGA microspheres for sustained delivery of Risperidone, with an eventual goal of avoiding combination therapy for the treatment of schizophrenia. Two PLGA copolymers (50 : 50 and 75 : 25) were used to prepare four microsphere formulations of Risperidone. The microspheres were characterized by several in vitro techniques. In vivo studies in male Sprague-Dawley rats at 20 and 40 mg/kg doses revealed that all formulations exhibited an initial burst followed by sustained release of the active moiety. Additionally, formulations prepared with 50 : 50 PLGA had a shorter duration of action and lower cumulative AUC levels than the 75 : 25 PLGA microspheres. A simulation of multiple dosing at weekly or 15-day regimen revealed pulsatile behavior for all formulations with steady state being achieved by the second dose. Overall, the clinical use of Formulations A, B, C, or D will eliminate the need for combination oral therapy and reduce time to achieve steady state, with a smaller washout period upon cessation of therapy. Results of this study prove the suitability of using PLGA copolymers of varying composition and molecular weight to develop sustained release formulations that can tailor in vivo behavior and enhance pharmacological effectiveness of the drug.

CYP450 pharmacogenetic treatment strategies for antipsychotics: a review of the evidence

Although a number of first- and second-generation antipsychotics are available, achieving optimal therapeutic response for patients with schizophrenia can be challenging. The presence of polymorphic alleles for cytochrome P (CYP) 450 may result in lack of expression, altered levels of expression, or altered function of CYP450 enzymes. CYP2D6, CYP1A2, and CYP3A4/5 are major enzymes in the metabolism of antipsychotics and polymorphisms of alleles for these proteins are associated with altered plasma levels. Consequently, standard dosing may result in drug plasma concentrations that are subtherapeutic or toxic in some patients. Patient CYP450 genotype testing can predict altered pharmacokinetics, and is currently available and relatively inexpensive. Evidence-based guidelines provide dose recommendations for some antipsychotics. To date few studies have demonstrated a significant association with genotype-guided antipsychotic use and clinical efficacy. However, many studies have been small, retrospective or cohort designs, and many have not been adequately powered. Numerous studies have shown a significant association between genotype and adverse effects, such as CYP2D6 polymorphisms and tardive dyskinesia. This review summarizes evidence for the role of CYP450 genetic variants in the response to antipsychotic medications and the clinical implications of pharmacogenetics in the management of patients with schizophrenia.

Risperidone, QTc interval prolongation, and torsade de pointes: a systematic review of case reports

RATIONALE

A recent publication asserted that even low-dose risperidone may induce corrected QT (QTc) interval prolongation up to 500 ms without drug-induced IKr blockade. We seek to better understand the complexity of any link between risperidone-induced/associated QTc interval prolongation and torsade de pointes (TdP).

OBJECTIVES

The objective of this study is to systematically analyze all available case reports of risperidone, QTc interval prolongation, and/or TdP.

METHOD

We identify case reports using PubMed, Medline, EMBASE, and Cochrane.

RESULTS

Of the 15 cases found, nine were adult women (ages 31, 33, 34, 37, 47, "elderly", 77, 84, and 87 years) and one was a teenager. There were four men (ages 28, 29, 29, and 46 years) and one preadolescent boy. Besides risperidone administration or overdose, traditional risk factors for QTc interval prolongation and TdP included female sex (n = 10), older age (n = 4), heart disease (n = 3), hypokalemia (n = 2), bradycardia (n = 1), liver disease (n = 1), QTc interval prolonging drugs other than risperidone (n = 8), and metabolic inhibitors (n = 2). TdP occurred in four cases. Six patients died, and three deaths were probably related to TdP.

CONCLUSION

Risperidone (when properly prescribed in patients free of other risk factors for QTc interval prolongation and TdP) is a relatively safe drug. Conventional statistics can neither predict the individual patient who will experience TdP nor determine the relationship of drug dose to QTc interval prolongation and TdP. Narrative medicine using a case report format appears to be an alternative and valuable additional approach to advance our understanding of this relationship and to reduce risks.

The psychopharmacology of aggressive behavior: a translational approach: part 2: clinical studies using atypical antipsychotics, anticonvulsants, and lithium

Patients experiencing mental disorders are at an elevated risk for developing aggressive behavior. In the past 10 years, the psychopharmacological treatment of aggression has changed dramatically owing to the introduction of atypical antipsychotics on the market and the increased use of anticonvulsants and lithium in the treatment of aggressive patients.This review (second of 2 parts) uses a translational medicine approach to examine the neurobiology of aggression, discussing the major neurotransmitter systems implicated in its pathogenesis (serotonin, glutamate, norepinephrine, dopamine, and γ-aminobutyric acid) and the neuropharmacological rationale for using atypical antipsychotics, anticonvulsants, and lithium in the therapeutics of aggressive behavior. A critical review of all clinical trials using atypical antipsychotics (aripiprazole, clozapine, loxapine, olanzapine, quetiapine, risperidone, ziprasidone, and amisulpride), anticonvulsants (topiramate, valproate, lamotrigine, and gabapentin), and lithium are presented. Given the complex, multifaceted nature of aggression, a multifunctional combined therapy, targeting different receptors, seems to be the best strategy for treating aggressive behavior. This therapeutic strategy is supported by translational studies and a few human studies, even if additional randomized, double-blind, clinical trials are needed to confirm the clinical efficacy of this framework.

Idiopathic granulomatous mastitis associated with risperidone-induced hyperprolactinemia

Idiopathic granulomatous mastitis (IGM) is a rare inflammatory breast disease. The etiology and treatment options of IGM remain controversial. Previous case reports have suggested that hyperprolactinemia may be associated with IGM. In the present report, we describe the first case of IGM associated with risperidone-induced hyperprolactinemia.

The role of paliperidone extended release for the treatment of bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a chronic, relapsing, episodic mental illness associated with other psychiatric comorbidities. There is a substantial economic burden with BD, which makes it challenging to treat. The aim of this review is to evaluate the pharmacology, clinical efficacy, and safety data related to paliperidone extended release (ER) for the treatment of BD.

METHODS

A literature search was performed from January 1966 through January 2012 using PreMEDLINE, MEDLINE, EMBASE, IPA, and ClinicalTrials.gov to identify articles in English regarding the pharmacology, clinical efficacy, and safety of paliperidone ER in acute mania or mixed episodes or in the maintenance treatment of BD I.

RESULTS

There are currently three published studies relating to the use of paliperidone ER for the treatment of BD. Two of these evaluated paliperidone ER as monotherapy for acute mania, while the other assessed its role as adjunct with a mood stabilizer.

CONCLUSION

According to the limited available evidence, paliperidone at higher doses of ER 9-12 mg/day may be a safe and efficacious treatment option for acute episodes of mania in BD. A once-daily dose formulation may improve patient adherence to treatment; however, the cost of paliperidone ER, which is higher than that of generically available second-generation antipsychotics (such as olanzapine and risperidone), and a lack of alternative dosage forms (ie, liquid, intramuscular) compared with other agents may limit its usefulness in the treatment of BD. The role of paliperidone ER as an adjunctive agent or for long-term use requires further investigation.

Risperidone modulates the cytokine and chemokine release of dendritic cells and induces TNF-α-directed cell apoptosis in neutrophils

Antipsychotic drugs (APDs) that bind mainly to the dopamine D2 receptor or the type II 5-HT receptor have been used to ease the symptoms of schizophrenia. Several studies have reported that APDs can also regulate the immune response. Dendritic cells (DCs) are the major antigen-presenting cells in the immune system. DCs can release 5-HT and dopamine to modulate T-cell activation and differentiation. In this study, we use the monocyte-derived DCs to investigate the drug effects of typical APD (haloperidol) and atypical APD (risperidone) on DCs in vitro. Our studies revealed that only risperidone but not haloperidol affected the cytokine and chemokine production of mature DCs. Risperidone increased the production of IL-10 and MDC as well as the proinflammatory cytokines, such as IL-6, IL-8, and TNF-α, but decreased the production of IP-10 and IL-12. Furthermore, the exposure of DCs to risperidone led to lower IFN-γ production by T-cells. The results suggested that risperidone can modulate the DCs' immune function by inhibiting the potent Th1 cytokines and increasing the potent Th2 cytokines. In addition, the production of TNF-α by risperidone-treated mature DCs will induce the death of neutrophils.

Spectroscopic properties of neuroleptics: IR and Raman spectra of Risperidone (Risperdal) and of its mono- and di-protonated forms

Structures and IR and Raman spectra of Risperidone in its neutral, mono- and di-protonated forms were calculated in gas phase by DFT-B3LYP/6-31G* level. Mono-protonation occurs at the nitrogen atom of the piperidine ring, while nitrogen atom of the pyrimidine ring is the preferred site for the second protonation. The lowest-energy structure of the mono-protonated Risperidone is characterized by formation of a strong seven-membered O(pyrimidine ring)⋯(+)H-N(piperidine ring) intramolecular hydrogen-bonded cycle. In the high-energy spectral region (3500-2500 cm(-1)), the bands of the N-H(+) stretches and the changes in wavenumbers and IR intensities of the C-H stretches near to the piperidine nitrogen atom (Bohlmann effect) are potentially useful to discriminate conformations and protonation states. Di-protonated structures can be identified by the presence of an isolated absorption peak located in the low-energy IR region (660-690 cm(-1)), attributed to the out-of-plane N-H(+)(pyrimidine ring) bending deformation. The most intense Raman band of neutral Risperidone placed at ca. 1500 cm(-1), assigned to C=C(pyrimidine ring) stretch + C=N(pyrimidine ring) stretch, can be a useful vibrational marker to distinguish the neutral from the protonated forms.

Paliperidone ER in the Treatment of Borderline Personality Disorder: A Pilot Study of Efficacy and Tolerability

Antipsychotics are recommended for the treatment of impulsive dyscontrol and cognitive perceptual symptoms of borderline personality disorder (BPD). Three reports supported the efficacy of oral risperidone on BPD psychopathology. Paliperidone ER is the metabolite of risperidone with a similar mechanism of action, and its osmotic release reduces plasmatic fluctuations and antidopaminergic effects. The aim of this study is to evaluate efficacy and safety of paliperidone ER in BPD patients. 18 outpatients with a DSM-IV-TR diagnosis of BPD were treated for 12 weeks with paliperidone ER (3-6 mg/day). They were assessed at baseline, week 4, and week 12, using the CGI-Severity item, the BPRS, the HDRS, the HARS, the SOFAS, the BPD Severity Index (BPDSI), and the Barratt Impulsiveness Scale (BIS-11). Adverse events were evaluated with the DOTES. Paliperidone ER was shown to be effective and well tolerated in reducing severity of global symptomatology and specific BPD symptoms, such as impulsive dyscontrol, anger, and cognitive-perceptual disturbances. Results need to be replicated in controlled trials.