Novel long-acting treatment for schizophrenia based on paliperidone dissolving and implantable microarray patches

Schizophrenia is a severe mental disorder that affects millions of people worldwide. Several atypical antipsychotic medications, including paliperidone (PPD), has been developed and proven effective in treating it. To date, four PPD extended-release products have been launched commercially, providing up to six months of therapeutic effect with a single administration. However, the need for hospital injections by professional healthcare workers not only lead to poor patients' adherence, but also put additional pressure on the healthcare system. Therefore, three PPD microarray patch (PPD MAP) systems based on dissolving microneedle technology and implantable microneedle technology were developed in this work. The two dissolving microarray patch systems contained either PPD crude drug (PPD DMAP-CD) or PPD nanocrystal (PPD DMAP-NC) and the implantable MAP contained PPD crude drug (PPD IMAP). All three types of PPD MAPs showed excellent mechanical and insertion properties as they achieved over 256 µm insertion depth in skin model. In vitro release study showed that PPD released from IMAP in a much more sustained manner (up to 14 days) than PPD did from DMAPs (7 days), with only 20 % initial burst release from IMAP compared with 43-71 % from DMAPs. The MAP dissolution study showed that both DMAPs can be immediately dissolved within less than 3 min once inserted into the skin, indicating a faster action potential compared with IMAP. Ex vivo delivery study showed that 1.68 ± 0.23 mg, 1.39 ± 0.07 mg, and 1.18 ± 0.12 mg were delivered from DMAP-CD, DMAP-NC and IMAP, respectively, demonstrating that over 50 % and up to 70 % of PPD in the MAPs can be delivered into the skin. The IMAP offers most sustained release of PPD whereas DMAP-NC exhibits fastest PPD release (11.19 % vs 20.01 % into Franz cell receiver compartment over 24 h). This work presents a promising alternative for the sustained delivery of antipsychotic drugs, allowing for patient self-administration and extended release concurrently. Patients may potentially use both DMAP and IMAP to achieve a sustained release of PPD while also avoid having an initial therapeutic lag.

Therapeutic Drug Monitoring of Paliperidone in Patients With Schizophrenia in Taiwan

BACKGROUND

The blood level of antipsychotics affects clinical responses to the drug; it can be influenced by race and several individual factors. This study analyzed the therapeutic plasma concentrations (Cps) of paliperidone for both oral and long-acting injectable (LAI) formulations in clinical samples from Taiwanese patients.

METHODS

Patients diagnosed with schizophrenia and treated with either oral paliperidone for at least 4 weeks or LAI paliperidone for at least 6 months were enrolled. Blood samples were taken before the morning dose of oral paliperidone or the injection of LAI paliperidone to obtain the trough Cps.

RESULTS

Among the patients in this study, 51 were taking oral paliperidone, and 26 were receiving LAI paliperidone. In the oral group, the mean Cps were 40.2 ± 19.8 ng/mL in patients taking 9 mg/d and 44.2 ± 15.9 ng/mL in those taking 12 mg/d. In the LAI group, the mean Cps were 32.9 ± 12.7 ng/mL in patients receiving 100 mg per 28 days and 49.9 ± 25.9 ng/mL in those receiving 150 mg per 28 days. The mean Cps per daily dose (Cps/DD) were 4.11 ± 1.99 ng/mL/mg in the oral group and 9.24 ± 3.78 ng/mL/mg in the LAI group.

CONCLUSIONS

Under the suggested DD for oral and LAI paliperidone treatment, most Taiwanese patients with schizophrenia can reach the suggested therapeutic Cps range. Wide interindividual differences were observed in the Cps/DD for both the oral (7-fold) and LAI paliperidone (4-fold) groups. Compared with Western reports, no difference was observed in the body weight-adjusted Cps/DD.

Risperidone Induced Hyperprolactinemia: From Basic to Clinical Studies

Risperidone is one of the most commonly used antipsychotics (AP), due to its safety and efficacy in reducing psychotic symptoms. Despite the favorable side effect profile, the therapy is accompanied by side effects due to the non-selectivity of this medicine. This review will briefly highlight the most important basic and clinical findings in this area, consider the clinical effects of AP-induced hyperprolactinemia (HPL), and suggest different approaches to the treatment.The route of application of this drug primarily affects the daily variation and the total concentration of drug levels in the blood, which consequently affects the appearance of side effects, either worsening or even reducing them. Our attention has been drawn to HPL, a frequent but neglected adverse effect observed in cases treated with Risperidone and its secondary manifestations. An increase in prolactin levels above the reference values result in impairment of other somatic functions (lactation, irregular menses, fertility) as well as a significant reduction in quality of life. It has been frequently shown that the side effects of the Risperidone are the most common cause of non-compliance with therapy, resulting in worsening of psychiatric symptoms and hospitalization. However, the mechanism of Risperidone-induced HPL is complicated and still far from fully understood. Most of the preclinical and clinical studies described in this study show that hyperprolactinemia is one of the most common if not the leading side effect of Risperidone therefore to improve the quality of life of these patients, clinicians must recognize and treat HPL associated with the use of these drugs.

Butyl stearate prolongs the drug release period of isoperidone‑loaded poly (lactic‑co‑glycolic acid) microspheres: In vitro and in vivo investigation

The present study aimed to investigate the effects of butyl stearate on t-butoxyl paliperidone derivative (isoperidone)-loaded poly(lactide-co-glycolide) (PLGA) microspheres. The mechanism of drug release rate delay by butyl stearate was examined by accelerated testing, morphological observation, thermal and fluorescence analyses. In vivo pharmacokinetic study was conducted on female beagle dogs. Spherical microspheres with smooth surfaces, small internal pores and shell structures were initially prepared. It was found that 3% (w/w) butyl stearate prolonged the in vitro drug release period from 46 to 82 days, and in vivo release period from 20 to 27 days. Furthermore, the results demonstrated that the green fluorescence imaging of isoperidone approaching the cores of microspheres with 3% butyl stearate was brighter than in microspheres without additives. In conclusion, it was shown that butyl stearate affected the microsphere structure, isoperidone microsphere distribution and isoperidone crystallinity. The results of the present study thus provide a potential method to develop sustained-release preparations.

Paliperidone, a relatively novel atypical antipsychotic drug, is a substrate for breast cancer resistance protein

Paliperidone (PAL) is a relatively novel atypical antipsychotic drug for schizophrenia that induces markedly varying responses. Breast cancer resistance protein (BCRP) is a recently discovered member of the ATP-binding cassette superfamily that has been used to control drug absorption, distribution and elimination, and especially to impede drug entry into the brain. To the best of our knowledge, the present study is the first to investigate the possibility of using PAL as a BCRP substrate. The intracellular accumulation and bidirectional transport were investigated using transfected 293 cell/BCRP and porcine renal endothelial cell (LLC-PK1)/BCRP cell monolayers and BCRP overexpression was confirmed by reverse transcription-quantitative polymerase chain reaction and western blot analysis. The in vitro affinity to BCRP was assessed in human BCRP (Arg482) membranes. The intracellular accumulation and bidirectional transport investigations demonstrated that BCRP can efflux PAL from cells and significantly decrease its cellular concentration over a concentration range of 0.1-50 µM. The in vitro affinity experiments indicated that PAL has a moderate affinity to BCRP at 0.1-100 µM. These results together suggest that PAL is a substrate for BCRP and that it can affect the blood-brain barrier penetration of PAL at therapeutic dosages.

Bilateral Pretibial Edema Associated with Paliperidone Palmitate Long-acting Injectable: A Case Report

Peripheral edema is observed as an adverse effect of the usage of antipsychotics in the literature. This case report describes a 36-year-old female patient with the diagnosis of paranoid schizophrenia who presented with pretibial edema following initiation of long-acting injectable paliperidone palmitate. Pretibial edema developed within the second week of treatment and completely disappeared after its discontinuation.

Multidisciplinary consensus on the therapeutic recommendations for iatrogenic hyperprolactinemia secondary to antipsychotics

Hyperprolactinemia is an underappreciated/unknown adverse effects of antipsychotics. The consequences of hyperprolactinemia compromise therapeutic adherence and can be serious. We present the consensus recommendations made by a group of experts regarding the management of antipsychotic-induced hyperprolactinemia. The current consensus was developed in 3 phases: 1, review of the scientific literature; 2, subsequent round table discussion to attempt to reach a consensus among the experts; and 3, review by all of the authors of the final conclusions until reaching a complete consensus. We include recommendations on the appropriate time to act after hyperprolactinemia detection and discuss the evidence on available options: decreasing the dose of the antipsychotic drug, switching antipsychotics, adding aripiprazole, adding dopaminergic agonists, and other type of treatment. The consensus also included recommendations for some specific populations such as patients with a first psychotic episode and the pediatric-youth population, bipolar disorder, personality disorders and the elderly population.

White-matter connectivity related to paliperidone treatment response in patients with schizophrenia

The objective of this study was to examine whether white-matter (WM) connectivity of patients with schizophrenia at early stage of treatment is related to treatment response after paliperidone extended-release (ER) treatment. Forty-one patients with schizophrenia and 17 age- and sex-matched healthy control subjects were included in this study. Brain magnetic resonance scans at 3 Tesla were conducted at early stage of treatment. Voxel-wise statistical analysis of the fractional anisotropy (FA) data was performed using Tract-Based Spatial Statistics. At baseline and eight weeks after paliperidone treatment, patients were assessed using the Positive and Negative Syndrome Scale, the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms. Among the patients with schizophrenia, the FA values of the corpus callosum, corona radiata, internal capsule, external capsule, superior longitudinal fasciculus and fronto-temporal WM regions showed significant negative correlations with scores of the treatment response. The current study suggests that the treatment response after paliperidone ER treatment may be associated with the fronto-temporo-limbic WM connectivity at early stage of treatment in patients with schizophrenia, and it could be used as a predictor of treatment response to paliperidone ER treatment after studies with large samples verify these results.

Spanish consensus on the risks and detection of antipsychotic drug-related hyperprolactinaemia

INTRODUCTION

Iatrogenic hyperprolactinaemia (IHPRL) has been more frequently related to some antipsychotic drugs that provoke an intense blockade of dopamine D2 receptors. There is a wide variation in clinical practice, and perhaps some more awareness between clinicians is needed. Due to the high frequency of chronic treatment in severe mental patients, careful attention is recommended on the physical risk. IHPRL symptoms could be underestimated without routine examination.

METHODOLOGY

An intense scientific literature search was performed in order to draw up a multidisciplinary consensus, including different specialists of psychiatry, endocrinology, oncology and internal medicine, and looking for a consensus about clinical risk and detection of IHPRL following evidence-based medicine criteria levels (EBM I- IV).

RESULTS

Short-term symptoms include amenorrhea, galactorrhoea, and sexual dysfunction with decrease of libido and erectile difficulties related to hypogonadism. Medium and long-term symptoms related to oestrogens are observed, including a decrease bone mass density, hypogonadism, early menopause, some types of cancer risk increase (breast and endometrial), cardiovascular risk increase, immune system disorders, lipids, and cognitive dysfunction. Prolactin level, gonadal hormones and vitamin D should be checked in all patients receiving antipsychotics at baseline although early symptoms (amenorrhea-galactorrhoea) may not be observed due to the risk of underestimating other delayed symptoms that may appear in the medium term. Routine examination of sexual dysfunction is recommended due to possible poor patient tolerance and low compliance. Special care is required in children and adolescents, as well as patients with PRL levels >50ng/ml (moderate hyperprolactinaemia). A possible prolactinoma should be investigated in patients with PRL levels >150ng/ml, with special attention to patients with breast/endometrial cancer history. Densitometry should be prescribed for males >50 years old, amenorrhea>6 months, or early menopause to avoid fracture risk.

Olanzapine-induced ischemic colitis

Ischemic colitis (IC) is an uncommon adverse event associated with antipsychotic agents, more commonly found with phenothiazine drugs and atypical neuroleptics such as clozapine. The risk of developing ischemic colitis increases when anticholinergic drugs are associated. We report the case of a 38-year-old woman with a history of schizoaffective disorder who had been on chronic quetiapine for 3 years, and presented to the ER because of diarrhea for 5 days. Four months previously, olanzapine had been added to her psychiatric drug regimen. Physical examination revealed abdominal distension with abdominal tympanic sounds and tenderness. Emergency laboratory tests were notable for increased acute phase reagents. Tomography revealed a concentric thickening of the colonic wall in the transverse, descending and sigmoid segments, with no signs of intestinal perforation. Colonoscopy demonstrated severe mucosal involvement from the sigmoid to the hepatic flexure, with ulcerations and fibrinoid exudate. Biopsies confirmed the diagnosis of ischemic colitis. The only relevant finding in her history was the newly added drug to her baseline regimen. An adverse effect was suspected because of its anticholinergic action at the intestinal level, and the drug was withdrawn. After 6 months of follow-up clinical, laboratory and endoscopic recovery was achieved. Therefore, antipsychotic medication should be considered as a potential cause of ischemic colitis, particularly atypical antipsychotics such as clozapine and olanzapine; despite being uncommon, this adverse event may result in high morbidity and mortality.

Early treatment response predicted subsequent clinical response in patients with schizophrenia taking paliperidone extended-release

This 6-week open-labeled study investigated whether early treatment response in patients receiving paliperidone extended-release (paliperidone ER) can facilitate prediction of responses at Week 6. Patients with schizophrenia or schizoaffective disorder were administered 9mg/day of paliperidone ER during the first 2 weeks, after which the dose was adjusted clinically. They were assessed on Days 0, 4, 7, 14, 28, and 42 by the Positive and Negative Syndrome Scale (PANSS). The serum concentrations of 9-hydroxyrisperidone were examined on Days 14 and 42. Among the 41 patients enrolled, 26 were classified as responders (≧50% improvement on total PANSS scores at Week 6). In the receiver-operator curves (ROC) analyses, the changes in total PANSS scores at Week 2 appeared to show more accurate predictability compared to Day 4 and Day 7. At Week 6, no significant correlation was observed between blood 9-hydroxyrisperidone concentration and the total score or changes of PANSS scores. The results suggest that early treatment response to paliperidone ER, particularly at Week 2, can serve as a suitable outcome predictor at Week 6. Using 9mg/day paliperidone ER as an initial dose for schizophrenia treatment exhibited relatively favorable tolerability and feasibility.

Effects of paliperidone extended release on functioning level and symptoms of patients with recent onset schizophrenia: An open-label, single-arm, flexible-dose, 12-months follow-up study

BACKGROUND

Response to antipsychotic treatment is better in the early stages of schizophrenia.

AIMS

The primary objective of this non-randomized, single-arm, multicenter clinical trial was to explore the response to treatment and safety of a flexible dose of paliperidone (mean = 6.42 mg/day) in patients with recent onset schizophrenia (< 3 years after the first episode/hospitalization).

METHODS

Severity of clinical symptoms was evaluated by the Positive and Negative Syndrome Scale (PANSS), functioning was assessed using the Global Assessment of Functioning (GAF) scale and the Personal and Social Performance Scale (PSP).

RESULTS

In a total of 85 patients enrolled, 80 patients were eligible. Total PSP score at baseline (50.2 ± 11.6) increased at all visits. Total PSP score was 65.4 ± 12.1 at month 12 (P < 0.001). GAF scores were significantly higher at all visits compared with baseline (P = 0.001). It was 62.4 ± 12.5 with an increase of 42.9% at month 12 (P < 0.001). PANSS Positive and Negative subscales and General psychopathology subscale scores showed significant reductions beginning with month 3 and were 11.9 ± 3.8 (29.3%; P < 0.001), 13.7 ± 5.6 (27.3% P < 0.001) and 27.8 ± 7.1 (23.2%; P < 0.001) at month 12, respectively. Twelve patients (14.3%) had a serious adverse event. The most common adverse events were insomnia (17.9%), nausea (8.3%), akathisia (4.8%), anxiety (4.8%) and depression (4.8%). Body weight values at the end of the study were significantly higher compared with baseline.

CONCLUSION

The present study demonstrates that flexible dose of paliperidone resulted in a significant improvement in functioning and reduction in symptoms in patients with recent onset schizophrenia.

Paliperidone and aripiprazole differentially affect the strength of calcium-secretion coupling in female pituitary lactotrophs

Hyperprolactinemia is a common adverse in vivo effect of antipsychotic medications that are used in the treatment of patients with schizophrenia. Here, we compared the effects of two atypical antipsychotics, paliperidone and aripiprazole, on cAMP/calcium signaling and prolactin release in female rat pituitary lactotrophs in vitro. Dopamine inhibited spontaneous cAMP/calcium signaling and prolactin release. In the presence of dopamine, paliperidone rescued cAMP/calcium signaling and prolactin release in a concentration-dependent manner, whereas aripiprazole was only partially effective. In the absence of dopamine, paliperidone stimulated cAMP/calcium signaling and prolactin release, whereas aripiprazole inhibited signaling and secretion more potently but less effectively than dopamine. Forskolin-stimulated cAMP production was facilitated by paliperidone and inhibited by aripiprazole, although the latter was not as effective as dopamine. None of the compounds affected prolactin transcript activity, intracellular prolactin accumulation, or growth hormone secretion. These data indicate that paliperidone has dual hyperprolactinemic actions in lactotrophs i) by preserving the coupling of spontaneous electrical activity and prolactin secretion in the presence of dopamine and ii) by inhibiting intrinsic dopamine receptor activity in the absence of dopamine, leading to enhanced calcium signaling and secretion. In contrast, aripiprazole acts on prolactin secretion by attenuating, but not abolishing, calcium-secretion coupling.

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

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

Influencing Factors and Predictors of Early Response in Schizophrenia Patients Receiving the Paliperidone Extended-Release Tablets (Paliperidone ER)

OBJECTIVE

Paliperidone extended-release tablet (paliperidone ER) is a new oral psychotropic agent developed for schizophrenia treatment. There have been some studies about paliperidone's good efficacy and tolerability. Clinicians appear to change the antipsychotic medication to paliperidone ER. However, it is not known what patients are favorable responsive to paliperidone ER. The aim of this study was to evaluate the characteristics of early responders and investigate predictors of acute response when the medications changed to paliperidone ER.

METHODS

Data were analyzed from schizophrenic patients who participated in a multi-center, open-label, non-comparative clinical trial. Total 320 patients were examined in this study. Sociodemographic, psychopathology, social function and metabolic data were evaluated. Unpaired t-test for continuous and χ(2) for categorical data, respectively, were used to compare early responder and non-responders. Logistic regression analysis was used to establish a prediction model.

RESULTS

38.7% of study subjects (124 of 320) responded to paliperidone ER treatment. Logistic regression analysis showed that a good paliperidone ER response was more likely when patients were social drinkers, when patients had started medication at inpatient, when negative symptoms were less severe, and when patients' social relationship and self-care were better.

CONCLUSION

Early response to paliperidone ER treatment is associated with less negative symptoms and good social relationships and self-care. Strategies to reduce these symptoms may contribute to early response to paliperidone ER.

Japan useful medication program for schizophrenia (JUMPs)-long-term study on discontinuation rate, resolution and remission, and improvement in social functioning rate associated with atypical antipsychotic medications in patients with schizophrenia

BACKGROUND

It is desirable to establish evidence for the selection of antipsychotics from the viewpoint of recovery of social activity in individual patient with schizophrenia receiving medication. From this perspective, awareness of the importance of studies about drug effectiveness on treatment discontinuation rate, remission rate, and improvement in QOL has grown recently. In Western countries, numerous reports are available in effectiveness studies, which are related to olanzapine and risperidone primarily, whereas evidence for other second-generation antipsychotics (SGAs) is poor. In Japan, no effectiveness study has been reported: thus, it is desirable to collect data that will serve as evidence for selection of the 3 SGAs approved after olanzapine.

METHODS

The present study was a long-term effectiveness study under healthcare setting in Japan. It was designed as an open-label, multicenter, randomized, comparative study involving 104-week oral treatment with 1 of the 3 drugs (aripiprazole, blonanserin, and paliperidone) in patients with schizophrenia aged 20 years or over who required antipsychotic medication or switching of the current medication to others for reasons such as lack of efficacy and intolerability. The primary endpoint is treatment discontinuation rate for any causes. The secondary endpoints include remission rate, improvement of social activity, alleviation, aggravation or recurrence of psychiatric symptoms, and safety. The target number of subjects was set at 300.

DISCUSSION

Because this study is expected to yield evidence regarding the selection of antipsychotics for facilitating the recovery of social activity in patients with schizophrenia, it is considered highly valuable to perform this effectiveness study under ordinary healthcare setting in Japan.

TRIAL REGISTRATION

UMIN Clinical Trials Registry 000007942.

A review of paliperidone palmitate

Risperidone long-acting injection (RLAI) was the first second-generation antipsychotic available as a long-acting injection. Paliperidone (9-hydroxyrisperidone) is the active metabolite of risperidone, introduced initially as an extended release oral (ORal Osmotic System, OROS®, Alza Corporation) formulation (Invega®, Janssen). Paliperidone long-acting injection (PLAI) has now been developed as a suspension of paliperidone palmitate nanocrystals in an aqueous formulation (Invega Sustenna®, Xeplion®), administered monthly by intramuscular injection (deltoid or gluteal). Doses of PLAI can be expressed either in milligram equivalents (mg eq) of paliperidone palmitate or in milligrams of the active fraction of paliperidone. The recommended initiation regimen of 150 mg eq (234 mg) on day 1 and 100 mg eq (156 mg) on day 8 (both administered in the deltoid) achieves therapeutic blood levels rapidly and without the necessity of oral supplementation. No refrigeration or reconstitution prior to administration is required. PLAI has been shown in to be effective in controlling the acute symptoms of schizophrenia as well as delaying time to relapse. Safety and tolerability are comparable to RLAI with no new safety signals. Thus, PLAI may represent the rational development of RLAI with greater ease of use.

Relationship between inflammation and metabolic syndrome following treatment with paliperidone for schizophrenia

OBJECTIVE

Metabolic syndrome and antipsychotic medications are associated with inflammation. This study investigated the relationship between inflammation and metabolic syndrome in patients with schizophrenia. It also examined the effects of paliperidone extended release (ER) treatment on metabolic parameters.

METHODS

Data were analyzed from schizophrenic patients who participated in a multi-center, open-label, non-comparative clinical trial. Anthropomorphic measurements (i.e., weight, waist circumference, and blood pressure) were assessed along with fasting laboratory values, including white blood cell (WBC) count, glucose, high-density lipoprotein, and triglycerides.

RESULTS

Among the 225 patients at baseline, the group with the highest WBC count displayed a 5.9-fold risk for metabolic syndrome compared with that of the lowest group. An increase of 10(3)WBCs/μL was associated with a 1.4-fold increased risk for metabolic syndrome. After 24weeks of treatment with paliperidone ER, significant increases were observed in waist circumference and body weight. Changes in WBC count were positively correlated with changes in waist circumference.

CONCLUSIONS

Schizophrenic patients with high levels of inflammation should be carefully monitored for metabolic syndrome. Moreover, strategies to reduce inflammation and obesity may prevent metabolic syndrome in patients with schizophrenia who take atypical antipsychotic medication.

Paliperidone extended release: in adolescents with schizophrenia

Paliperidone, the major active metabolite of risperidone, is an atypical antipsychotic agent formulated as an extended-release (ER) tablet suitable for once-daily oral administration. Paliperidone ER is approved for the treatment of adolescents aged 12-17 years with schizophrenia in the US (the focus of this review). It is also approved for the treatment of adults with schizophrenia or schizoaffective disorder. Paliperidone ER has shown efficacy in the treatment of patients aged 12-17 years with acutely symptomatic schizophrenia in a randomized, double-blind, parallel-group, placebo-controlled, multicenter, 6-week trial. The primary endpoint was the change from baseline in Positive and Negative Syndrome Scale (PANSS) total score to day 43 or the final assessment point post-baseline. Patients with a PANSS total score of 60-120 received one of three weight-based, fixed once-daily doses of paliperidone ER (patients weighing 29 kg to <51 kg: 1.5 mg [low-dose], 3 mg [medium], or 6 mg [high]; patients weighing ≥51 kg: 1.5 mg [low], 6 mg [medium], or 12 mg [high]), or placebo. Compared with placebo, significant improvements in mean PANSS total scores were reported for the medium-dose (3-6 mg) paliperidone ER treatment groups. There were no significant differences in mean PANSS total scores between the recipients of low-dose or high-dose paliperidone ER versus placebo. Mean PANSS total scores in the actual dose treatment groups (regardless of weight) decreased from baseline (i.e. improved) and were significantly lower for the 3, 6, and 12 mg groups than for the placebo group. Treatment-emergent adverse events were dose related in adolescents with schizophrenia who received weight-based fixed doses of paliperidone ER.

Paliperidone for irritability in adolescents and young adults with autistic disorder

RATIONALE

Individuals with autistic disorder (autism) frequently exhibit significant irritability marked by severe tantrums, aggression, and self-injury. Despite advances in the treatment of this symptom domain in autism, there remains an ongoing need for more effective and better tolerated pharmacotherapies.

OBJECTIVES

The aim of this study is to determine the effectiveness and tolerability of paliperidone for irritability in autism.

METHODS

This is a prospective, 8-week open-label study of paliperidone in 25 adolescents and young adults with autism. Primary outcome measures included the Clinical Global Impressions-Improvement (CGI-I) Scale and the Irritability subscale of the Aberrant Behavior Checklist (ABC-I). Concomitant medications (except antipsychotics) were permitted if dosages were stable for ≥2 months.

RESULTS

Twenty-one (84 %) of 25 subjects ages 12-21 years (mean 15.3 years) responded to paliperidone, based on a CGI-I Scale score of 1 or 2 (very much or much improved) and ≥25 % improvement on the ABC-I. The mean final dosage of paliperidone was 7.1 mg/day (range 3-12 mg/day). Two subjects discontinued paliperidone prior to study completion (moderate sedation, n = 1; nonresponse, n = 1). Mild-to-moderate extrapyramidal symptoms were recorded in four subjects. A mean weight gain of 2.2 ± 2.6 kg (range -3.6 to +7.9 kg) was recorded. Mean age- and sex-normed body mass index increased from 23.6 to 24.2 (p ≤ 0.001). Mean serum prolactin increased from 5.3 to 41.4 ng/mL (p ≤ 0.0001).

CONCLUSIONS

Paliperidone treatment was associated with significant improvement in irritability and was generally well tolerated. Larger scale, placebo-controlled studies are needed to elucidate the efficacy and tolerability of paliperidone in this population.

Changes in body weight and psychotropic drugs: a systematic synthesis of the literature

INTRODUCTION

Psychotropic medication use is associated with weight gain. While there are studies and reviews comparing weight gain for psychotropics within some classes, clinicians frequently use drugs from different classes to treat psychiatric disorders.

OBJECTIVE

To undertake a systematic review of all classes of psychotropics to provide an all encompassing evidence-based tool that would allow clinicians to determine the risks of weight gain in making both intra-class and interclass choices of psychotropics.

METHODOLOGY AND RESULTS

We developed a novel hierarchical search strategy that made use of systematic reviews that were already available. When such evidence was not available we went on to evaluate randomly controlled trials, followed by cohort and other clinical trials, narrative reviews, and, where necessary, clinical opinion and anecdotal evidence. The data from the publication with the highest level of evidence based on our hierarchical classification was presented. Recommendations from an expert panel supplemented the evidence used to rank these drugs within their respective classes. Approximately 9500 articles were identified in our literature search of which 666 citations were retrieved. We were able to rank most of the psychotropics based on the available evidence and recommendations from subject matter experts. There were few discrepancies between published evidence and the expert panel in ranking these drugs.

CONCLUSION

Potential for weight gain is an important consideration in choice of any psychotropic. This tool will help clinicians select psychotropics on a case-by-case basis in order to minimize the impact of weight gain when making both intra-class and interclass choices.

[Study of Flexible Doses of Paliperidone ER in Pacients with Schizophrenia who Have Undergone Inefficient Treatment with other Antipsychotics]

BACKGROUND

Extended-release (ER) paliperidone is an innovative atypical antipsychotic that allows minimal peak-to-through fluctuations with once-daily dosing.

OBJECTIVE

To evaluate effectiveness, safety and tolerability of flexible, once-daily doses of paliperidone ER (3-12 mg/day) in patients with schizophrenia from Argentina and Colombia who had previously failed treatment with other antipsychotic agents.

METHODS

The authors conducted a 6-month, open-label, prospective and multicentric study. Effectiveness was assessed with Positive and Negative Syndrome Scale (PANSS) and Personal and Social Performance scale (PSP). Other measures of effectiveness, safety and tolerability, were also conducted.

RESULTS

Paliperidone ER 3-12 mg/day improved Positive and Negative Syndrome Scale (PANSS) total scores (primary endpoint) from baseline to study end (p < 0,001). In the PANSS total score, the mean change from baseline (83, 9 units) to end point (53,7 units) was significant (p < 0,001). Flexible doses of paliperidone ER demonstrated a ≥20% reduction in the PANSS total score (p<0.001) in almost two-thirds of patients. PSP mean change from baseline (52 units) to end point (85 units) was significant (p < 0,001). Secondary effectiveness assessments, as well as safety and tolerability measures, demonstrated favourable results throughout the study.

CONCLUSIONS

Flexible doses of paliperidone ER over 6 months were effective, safe and well tolerated in patients with schizophrenia from Argentina and Colombia.

Comparative fasting bioavailability of dispersible and conventional tablets of risperidone: a single-dose, randomized-sequence, open-label, two-period crossover study in healthy male Chinese volunteers

BACKGROUND

Risperidone (RIS), an atypical antipsychotic drug, is used for the treatment of psychoses associated with schizophrenia and other psychiatric disorders in adult and pediatric populations. An oral dispersible tablet formulation of risperidone has been developed. This study was conducted to provide support for marketing authorization of this drug in China.

OBJECTIVE

This study was designed to compare the pharmacokinetic (PK) properties and bioavailability of 2 RIS formulations-the dispersible formulation (test) and a branded formulation (reference) in healthy male Chinese volunteers.

METHODS

This single-dose, randomized-sequence, open-label, 2-period crossover study involved 22 healthy male Chinese volunteers. Equal numbers of eligible participants were randomly assigned to receive either the test drug (2 mg) or the same dose of the reference formulation, followed by a 2-week washout period and administration of the alternate formulation. The study drugs were administered after a 10-hour overnight fast. Blood samples were collected before dosing and at 0.33, 0.67, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 15, 24, 36, 48, 72, and 96 hours after dosing. Plasma concentrations of RIS and its active metabolite, 9-hydroxyrisperidone (9-OH-RIS), were measured using LC-MS/MS. The safety profile was evaluated by recording adverse events (AEs), assessed using physical examination including vital signs, spontaneous reporting, and clinical laboratory results. The 2 formulations were considered to have met the requirements for bioequivalence if the 90% CIs for the log-transformed C(max) and AUC values were within the predetermined ranges of 75% to 133% and 80% to 125%, respectively, according to the guidelines of the State Food and Drug Administration (SFDA) of China.

RESULTS

All 22 volunteers (mean [SD] age, 22.2 [1.98] years; weight, 64.07 [5.93] kg; height, 173 [5] cm; and body mass index, 21.2 [1.67] kg/m(2)) that were enrolled completed the study. For RIS, the 90% CIs for the ratios of C(max), AUC(0-t), and AUC(0-∞) were 93.2% to 116.7%, 97.9% to 111.3%, and 98.0% to 111.6%, respectively. For 9-OH-RIS, the 90% CIs were 95.8% to 113.9%, 100.2% to 109.7%, and 100.5% to 110.3%, respectively. All values were within the predetermined bioequivalence range. Seven AEs were reported somnolence (4 subjects [9.1%]) and dizziness (3 subjects [6.8%]). All AEs were transient and considered mild by physicians.

CONCLUSIONS

The test (dispersible) and reference tablets met the regulatory criteria for bioequivalence as defined by the SFDA. Both formulations were well tolerated. Chinese Clinical Trials registration number: ChiCTR-TRC-12001996.

Toxicology and overdose of atypical antipsychotics

BACKGROUND

Second-generation antipsychotic medications, or "atypical antipsychotics," are now first-line therapy in the treatment of schizophrenia and other psychotic disorders, and are additionally being used in a wide array of other psychiatric and non-psychiatric conditions in both adults and children. Overdose is frequently reported to poison control centers.

OBJECTIVES

We review the toxicology and general management of poisonings involving the atypical antipsychotic medications.

DISCUSSION

The most serious toxicity involves the cardiovascular system and the central nervous system. All typical and atypical antipsychotics cause sedation, which is pronounced in overdose. The most common cardiovascular effects that occur after atypical antipsychotic overdose are tachycardia, mild hypotension, and prolongation of the QTc interval. Other clinical syndromes in overdose include neuroleptic malignant syndrome (NMS) and antimuscarinic delirium. Seizures may be observed. No antidotes exist for these poisonings, but they most often do well with supportive care.

CONCLUSION

Antipsychotic overdose produces a gamut of manifestations that affect multiple organ systems. Treatment is primarily supportive. Specific therapies for NMS, hypotension, and seizures are discussed.

QT prolongation of the antipsychotic risperidone is predominantly related to its 9-hydroxy metabolite paliperidone

OBJECTIVE

A dose-dependent increase in risk of sudden cardiac death for the antipsychotic drug risperidone was reported. However, few reports have so far addressed QT prolongation associated with the use of risperidone or its major active metabolite, which is also used as a separate antipsychotic drug, paliperidone.

METHODS

The present study evaluated associations between risperidone metabolism and QT interval in 61 psychiatric patients who had been receiving risperidone for ≥4 weeks at an average dosage of 4.7 mg/day. Plasma risperidone and paliperidone levels were measured and electrocardiographic measurements were also obtained.

RESULTS

There was no correlation between risperidone dosage and QTc or plasma risperidone levels and QTc. However, there was a significant positive correlation between plasma paliperidone levels and QTc (r = 0.361; p = 0.004). There was no correlation between age and dose-corrected plasma risperidone levels or between age and QTc. There was a significant positive correlation between age and dose-corrected plasma paliperidone levels (r = 0.290; p = 0.023).

CONCLUSION

Clinically, paliperidone is considered to play a more important role in QT prolongation than risperidone.

Delivery systems and dosing for antipsychotics

Schizophrenia is a devastating illness, affecting approximately 1-2 % of the world population. Age of onset is generally between 20 and 30 years of age with a chronic, unremitting course for the duration of the patient's life. Although schizophrenia is among the most severe and debilitating illnesses known to medicine, its treatment has remained virtually unchanged for over 50 years. This chapter covers several major concepts in experimental drug development and delivery: (1) the concept of "typical" vs. "atypical" classifications for antipsychotic drugs as it relates to dosing; (2) the development of depot formulations for improved medication adherence; and (3) several promising areas for future therapeutic advances related to the methods and duration of drug administration. These areas include sublingual, injectable, and implantable drug delivery strategies that have the potential to effect rapid and dramatic improvements in schizophrenia outcomes.

Oral paliperidone: a review of its use in the management of schizoaffective disorder

Oral paliperidone extended or prolonged release (Invega®) is an atypical antipsychotic, and is the first agent approved for the treatment of schizoaffective disorder. Paliperidone (or 9-hydroxyrisperidone) is the major active metabolite of the well known atypical antipsychotic risperidone, and its mechanism of action is thought to be the antagonism of dopamine D(2) and serotonin 5-HT(2A) receptors. The clinical efficacy of paliperidone was demonstrated in two 6-week, randomized, double-blind, placebo-controlled, multicentre trials in patients with schizoaffective disorder. One trial was flexible dose in design (3-12 mg/day) and the other was fixed dose in design (3-6 and 9-12 mg/day). Compared with placebo, the change from baseline at study end in the Positive and Negative Syndrome Scale (PANSS) total score (primary endpoint) was significantly greater with paliperidone 3-12 mg/day in one trial and with 9-12 mg/day (but not 3-6 mg/day) in the other trial. However, pooled analyses reported a significantly greater change in PANSS total score across all paliperidone dosages than with placebo. Paliperidone was generally well tolerated in the 6-week trials, and no unexpected adverse events were reported. The most commonly reported treatment-emergent adverse events were headache, tremor, dizziness, insomnia, nausea, akathisia, dyspepsia, hypertonia, somnolence and sedation. Although long-term efficacy and tolerability data and comparisons with other antipsychotics are needed, paliperidone appears to be a useful agent for the short-term management of patients with schizoaffective disorder.

Emerging drugs for schizophrenia

INTRODUCTION

Since the development of clozapine, scores of antipsychotics have been introduced. These are, with one exception (aripiprazole), based on the pharmacological principle of 5-HT(2)/dopamine antagonism. Research on other treatment targets, which, in part, influence dopaminergic pathways directly or indirectly, is mounting. Managing psychotic symptoms is only one facet of successful treatment of schizophrenia. Effective remedies against negative symptoms and cognitive deficits are still an unmet clinical need.

AREAS COVERED

With the focus on the topics mentioned above, the authors briefly review the latest clinical research organized on the basis of receptor systems and other drug targets, which are discussed to be involved in the pathophysiology of schizophrenia.

EXPERT OPINION

In conclusion, although clinicians will have to have considerable patience before truly novel anti-schizophrenia treatments become obtainable, a number of interesting leads with considerable theoretical potential are being explored. As yet, it is difficult to predict which of these mechanisms will effectively augment the currently available treatments.

Safety and efficacy of paliperidone extended-release in acute and maintenance treatment of schizophrenia

Paliperidone, the major active metabolite of risperidone, is a second-generation antipsychotic that has been developed as an extended-release (ER) tablet formulation that minimizes peak-trough fluctuations in plasma concentrations, allowing once-daily administration and constant drug delivery. Paliperidone ER has demonstrated efficacy in the reduction of acute schizophrenia symptoms in 6-week, placebo-controlled, double-blind trials and clinical benefits were maintained in the longer-term according to extension studies of up to 52 weeks in duration. Compared with quetiapine, paliperidone ER was associated with a more rapid symptom improvement. In addition, it was more effective than placebo in the prevention of symptom recurrence. Paliperidone ER is generally well tolerated with a predictable adverse event profile. Like risperidone, it is associated with a dose-dependent risk of extrapyramidal symptoms and prolactin elevation. Short- and longer-term studies have indicated a low liability for paliperidone ER to cause metabolic (ie, weight gain, hyperglycaemia and lipid dysregulation) or cardiovascular adverse effects. Available safety data from elderly patients appear to be promising. Due to negligible hepatic biotransformation, paliperidone ER is unlikely to be involved in clinically significant metabolic drug-drug interactions. Additional active comparator trials evaluating efficacy, tolerability and cost-effectiveness are required to better define the role of paliperidone ER in the treatment of schizophrenia in relation to other currently available second-generation antipsychotics, particularly risperidone.