Aripiprazole: a review of its use in schizophrenia and schizoaffective disorder

Aripiprazole-induced transient myopia: A rare entity

Aripiprazole is a new drug for the treatment of adults with schizophrenia. Ocular side effects of aripiprazole are very rare. Review of literature revealed few cases of aripiprazole-induced myopia. We report a rare case of aripiprazole-induced transient myopia. A 22-year-old female patient presented to the department of psychiatry with worsening of symptoms of schizophrenia and was started on aripiprazole. She presented with complaints of blurring of vision in both eyes for 1 week which started on the 3^rd day following the use of aripiprazole. Anterior segment examination revealed a shallow anterior chamber and narrow angles. Intraocular pressure was normal. A diagnosis of aripiprazole-induced acute myopia was made and the treating psychiatrist was advised to stop the medication. At 2-week follow-up, the unaided visual acuity improved to 20/20 in both the eyes. Ophthalmologists should be aware of the myopic shift that may occur as an ocular side effect with aripiprazole.

Aripiprazole, A Drug that Displays Partial Agonism and Functional Selectivity

BACKGROUND

The treatment of schizophrenia is challenging due to the wide range of symptoms (positive, negative, cognitive) associated with the disease. Typical antipsychotics that antagonize D2 receptors are effective in treating positive symptoms, but extrapyramidal side-effects (EPS) are a common occurrence. Atypical antipsychotics targeting 5-HT2A and D2 receptors are more effective at treating cognitive and negative symptoms compared to typical antipsychotics, but these drugs also result in side-effects such as metabolic syndromes.

OBJECTIVE

To identify evidence in the literature that elucidates the pharmacological profile of aripiprazole.s.

METHODS

We searched PubMed for peer reviewed articles on aripiprazole and its clinical efficacy, side-effects, pharmacology, and effects in animal models of schizophrenia symptoms.

RESULTS

Aripiprazole is a newer atypical antipsychotic that displays a unique pharmacological profile, including partial D2 agonism and functionally selective properties. Aripiprazole is effective at treating the positive symptoms of schizophrenia and has the potential to treat negative and cognitive symptoms at least as well as other atypical antipsychotics. The drug has a favorable side-effect profile and has a low propensity to result in EPS or metabolic syndromes. Animal models of schizophrenia have been used to determine the efficacy of aripiprazole in symptom management. In these instances, aripiprazole resulted in the reversal of deficits in extinction, pre-pulse inhibition, and social withdrawal. Because aripiprazole requires a greater than 90% occupancy rate at D2 receptors to be clinically active and does not produce EPS, this suggests a functionally selective effect on intracellular signaling pathways.

CONCLUSION

A combination of factors such as dopamine system stabilization via partial agonism, functional selectivity at D2 receptors, and serotonin-dopamine system interaction may contribute to the ability of aripiprazole to successfully manage schizophrenia symptoms. This review examines these mechanisms of action to further clarify the pharmacological actions of aripiprazole.

Synthesis, Molecular Properties Estimations, and Dual Dopamine D2 and D3 Receptor Activities of Benzothiazole-Based Ligands

Neurleptic drugs, e.g., aripiprazole, targeting the dopamine D_2S and D₃ receptors (D_2SR and D₃R) in the central nervous system are widely used in the treatment of several psychotic and neurodegenerative diseases. Therefore, a new series of benzothiazole-based ligands (3-20) was synthesized by applying the bioisosteric approach derived from the selective D₃Rs ligand BP-897 (1) and its structurally related benz[d]imidazole derivative (2). Herein, introduction of the benzothiazole moiety was well tolerated by D_2SR and D₃R binding sites leading to antagonist affinities in the low nanomolar concentration range at both receptor subtypes. However, all novel compounds showed lower antagonist affinity to D₃R when compared to that of 1. Further exploration of different substitution patterns at the benzothiazole heterocycle and the basic 4-phenylpiperazine resulted in the discovery of high dually acting D_2SR and D₃R ligands. Moreover, the methoxy substitution at 2-position of 4-phenylpiperazine resulted in significantly (22-fold) increased D_2SR binding affinity as compared to the parent ligand 1, and improved physicochemical and drug-likeness properties of ligands 3-11. However, the latter structural modifications failed to improve the drug-able properties in ligands having un-substituted 4-phenylpiperazine analogs (12-20). Accordingly, compound 9 showed in addition to high dual affinity at the D_2SR and D₃R [K_i (hD_2SR) = 2.8 ± 0.8 nM; K_i (hD₃R) = 3.0 ± 1.6 nM], promising clogS, clogP, LE (hD_2SR, hD₃R), LipE (hD_2SR, hD₃R), and drug-likeness score values of −4.7, 4.2, (0.4, 0.4), (4.4, 4.3), and 0.7, respectively. Also, the deaminated analog 10 [K_i (hD_2SR) = 3.2 ± 0.4 nM; K_i (hD₃R) = 8.5 ± 2.2 nM] revealed clogS, clogP, LE (hD_2SR, hD₃R), LipE (hD_2SR, hD₃R) and drug-likeness score values of −4.7, 4.2, (0.4, 0.4), (3.9, 3.5), and 0.4, respectively. The results observed for the newly developed benzothiazole-based ligands 3-20 provide clues for the diversity in structure activity relationships (SARs) at the D_2SR and D₃R subtypes.

Current and potential pharmacological and psychosocial interventions for anxiety symptoms and disorders in patients with schizophrenia: structured review

OBJECTIVE

Between 30% and 62% of patients with schizophrenia present with co-morbid anxiety disorders that are associated with increased overall burden. Our aim was to summarize current and potential interventions for anxiety in schizophrenia.

DESIGN

Structured review, summarizing pharmacological and psychosocial interventions used to reduce anxiety in schizophrenia and psychosis.

RESULTS

Antipsychotics have been shown to reduce anxiety, increase anxiety, or have no effect. These may be augmented with another antipsychotic, anxiolytic, or antidepressant. Novel agents, such as L-theanine, pregabalin, and cycloserine, show promise in attenuating anxiety in schizophrenia. Psychosocial therapies have been developed to reduce the distress of schizophrenia. Cognitive behavioural therapy (CBT) has shown that benefit and refinements in the therapy have been successful, for example, for managing worry in schizophrenia. CBT usually involves more than 16 sessions, as short courses of CBT do not attenuate the presentation of anxiety in schizophrenia. To address time and cost, the development of manualized CBT to address anxiety in schizophrenia is being developed.

CONCLUSIONS

The presence of coexisting anxiety symptoms and co-morbid anxiety disorders should be ascertained when assessing patients with schizophrenia or other psychoses as a range of pharmacological and psychosocial treatments are available.

Aripiprazole Lauroxil: Pharmacokinetic Profile of This Long-Acting Injectable Antipsychotic in Persons With Schizophrenia

BACKGROUND

Aripiprazole lauroxil is an extended-release prodrug of aripiprazole for intramuscular injection, approved for schizophrenia treatment. We developed a population pharmacokinetic (PopPK) model to characterize aripiprazole lauroxil PK and evaluate dosing scenarios likely to be encountered in clinical practice.

METHODS

Data from 616 patients with schizophrenia, collected from 5 clinical studies, were used to construct the PopPK model. The model was subsequently used to evaluate various dose levels and frequency and the impact of dosing delay on aripiprazole concentrations.

FINDINGS

The results of the model indicate that aripiprazole is released into the systemic circulation after 5 to 6 days, and release continues for an additional 36 days. The slow increase in aripiprazole concentration after injection necessitates the coadministration of oral aripiprazole for 21 days with the first injection. Based on the PopPK model simulations, a dosing interval of 882 mg every 6 weeks results in aripiprazole concentrations that fall within the concentration range associated with the efficacious aripiprazole lauroxil dose range (441-882 mg dosed monthly). A 662-mg monthly dose also resulted in aripiprazole concentrations within the efficacious dose range. Aripiprazole lauroxil administration results in prolonged exposure, such that dose delays of 2 to 4 weeks, depending on the dose regimen, do not require oral aripiprazole supplementation upon resumption of dosing.

CONCLUSIONS

This PopPK model and model-based simulations were effective means for evaluating aripiprazole lauroxil dosing regimens and management of missed doses. Such analyses play an important role in determining the use of this long-acting antipsychotic in clinical practice.

Sex differences in aripiprazole sensitization from adolescence to adulthood

The present study investigated the potential sex differences in repeated aripiprazole (ARI) treatment-induced behavioral sensitization from adolescence to adulthood, and to determine whether ARI sensitization can be transferred to olanzapine (OLZ) and/or clozapine (CLZ) using the conditioned avoidance response (CAR) and phencyclidine-induced (PCP) hyperlocomotion tests of antipsychotic activity. Male and female Sprague-Dawley adolescence rats (P46) were first treated with ARI (10mg/kg) for 5 consecutive days (P46-50) and tested for avoidance response and ARI-induced inhibition of PCP-induced hyperlocomotion. After they became adults (>P68), rats were challenged with ARI (1.5mg/kg, sc) (P70), OLZ (0.5mg/kg, sc; P73), CLZ (5mg/kg, sc; P76) and again with ARI (1.5mg/kg, sc; P84) and tested for avoidance response and ARI-induced inhibition of PCP-induced hyperlocomotion again. During the drug treatment period in adolescence, repeated ARI treatment suppressed avoidance response, inhibited the PCP-induced hyperlocomotion, and these effects were progressively increased across the 5-day period in both males and females, confirming the induction of ARI sensitization. On the challenge days, rats previously treated with ARI in adolescence also had significantly lower avoidance and lower PCP-induced hyperlocomotion than the previous vehicle rats, confirming the expression of ARI sensitization and its persistence into adulthood. More importantly, female rats made significantly more avoidances than males in both ARI and vehicle groups, indicating higher sensitivity to the acute and long-term effects of ARI. Further, on the OLZ and CLZ challenge days, prior ARI treatment seemed to increase sensitivity to OLZ exposure, however, this increase was not significant. Similarly, rats also showed an ARI sensitization to OLZ and CLZ on challenge days. Collectively, results from this experiment demonstrated a sex difference in response to ARI and enhanced inhibition of PCP-induced hyperlocomotion in animals that were pretreated with ARI as compared to controls.

Discovery of G Protein-Biased D2 Dopamine Receptor Partial Agonists

Biased ligands (also known as functionally selective ligands) of G protein-coupled receptors are valuable tools for dissecting the roles of G protein-dependent and independent signaling pathways in health and disease. Biased ligands have also been increasingly pursued by the biomedical community as promising therapeutics with improved efficacy and reduced side effects compared with unbiased ligands. We previously discovered first-in-class β-arrestin-biased agonists of dopamine D2 receptor (D2R) by extensively exploring multiple regions of aripiprazole, a balanced D2R agonist. In our continuing efforts to identify biased agonists of D2R, we unexpectedly discovered a G protein-biased agonist of D2R, compound 1, which is the first G protein-biased D2R agonist from the aripiprazole scaffold. We designed and synthesized novel analogues to explore two regions of 1 and conducted structure-functional selectivity relationship (SFSR) studies. Here we report the discovery of 1, findings from our SFSR studies, and characterization of novel G protein-biased D2R agonists.

Evaluation of the Relationship Between Pharmacokinetics and the Safety of Aripiprazole and Its Cardiovascular Effects in Healthy Volunteers

AIMS

The aim of this study was the evaluation of the possible relationship between pharmacokinetics and the safety of aripiprazole as well as its influence on blood pressure (BP), heart rate (HR), and corrected QT (QTc) interval.

METHODS

The study population comprised 157 healthy volunteers from 6 bioequivalence clinical trials. Subjects were administered a single 10-mg oral dose of each formulation separated by a 28-day washout period. Plasma concentrations were measured using high-performance liquid chromatography coupled to mass spectrometry. Blood pressure was measured at the following times: predose and 0.5, 2, 4, 6, and 8 hours postdose. An electrocardiogram was recorded at predose, 4, and 8 hours postdose.

RESULTS

Area under the curve (AUC), maximum plasma concentration, half-life, and distribution volume corrected for weight were higher in women. Aripiprazole treatment produced a decrease of BP (9.3 mm Hg on systolic and 6.2 mm Hg on diastolic pressure) and an increase in HR (12.1 beats per minute) and QTc interval (9.1 milliseconds). There were sex differences in BP, HR, and QTc interval. Women and subjects with higher AUC and maximum plasma concentration values were more prone to experience adverse drug reactions and gastrointestinal adverse reactions. The AUC was related with systolic BP and diastolic BP decrease and HR increase but there was no relationship between aripiprazole concentrations and QTc increase.

CONCLUSIONS

Aripiprazole decreases BP and increases HR and QTc interval. Pharmacokinetics, pharmacodynamics, and safety of aripiprazole are affected by sex. There is a directly proportional relationship between pharmacokinetic parameters and adverse drug reactions and effect on BP and HR.

Prediction of an Optimal Dose of Aripiprazole in the Treatment of Schizophrenia From Plasma Concentrations of Aripiprazole Plus Its Active Metabolite Dehydroaripiprazole at Week 1

BACKGROUND

It has been suggested that a plasma trough concentration of aripiprazole plus its active metabolite, dehydroaripiprazole of 225 ng/mL is a threshold for a good therapeutic response in the treatment of acutely exacerbated patients with schizophrenia. The present study investigated whether or not an optimal dose of aripiprazole could be predicted from these concentrations at week 1.

METHODS

The subjects were 26 inpatients with schizophrenia, who received aripiprazole once a day for 3 weeks. The daily doses were 12 mg for the first week and 24 mg for the next 2 weeks. No other drugs except biperiden and flunitrazepam were coadministered. Blood samples were taken at weeks 1 and 3 after the treatment. Plasma concentrations of aripiprazole and dehydroaripiprazole were measured using liquid chromatography with mass-spectrometric detection.

RESULTS

There was a significant linear relationship between the plasma concentrations of aripiprazole plus dehydroaripiprazole at weeks 1 (x) and 3 (y) (P < 0.001). Regression equation was y = 2.580x + 34.86 (R = 0.698). Based on the equation, a nomogram to estimate an optimal dose of aripiprazole could be constructed.

CONCLUSIONS

The present study suggests that an optimal dose of aripiprazole for the treatment of patients with schizophrenia can be predicted from the plasma concentrations of the sum of the 2 compounds at week 1.

Therapeutic effectiveness and tolerability of aripiprazole as initial choice of treatment in first episode psychosis in an early intervention service: A one-year outcome study

INTRODUCTION

Aripiprazole has been associated with a low prevalence of metabolic side effects as compared to other second generation antipsychotic (SGA) medications mostly in patients with long standing illness. The purpose of the present study was to assess specifically the effectiveness and safety of aripiprazole as a first choice for antipsychotic therapy for young patients presenting with a previously untreated first episode of a psychotic disorder (FEP).

METHODS

Seventy-three patients presenting with a FEP and with minimal prior exposure to antipsychotic medications were recruited to be part of an open label naturalistic outcome study using aripiprazole as the first choice of antipsychotic medication. Data on positive, negative and total symptom severity including general psychopathological symptoms, level of functioning and metabolic indices were collected prospectively over a one-year period.

RESULTS

As compared to baseline, patients treated with aripiprazole (mean dose 9.6mg) improved significantly on measures of positive (p<0.001), negative (p<0.001) and total severity-general psychopathology symptoms (p<0.001) and level of functioning (p<0.001). Seventy two percent of the participants achieved positive symptom remission and 50% achieved total remission (positive and negative) at one year of follow up. Unlike reports on patients with longer standing illness, significant weight gain (p<0.001) was observed, with 44% of participants experiencing >7% increase in body weight.

CONCLUSION

FEP patients starting treatment with aripiprazole improved on symptoms and social and occupational functioning. Aripiprazole was well tolerated except for a significant weight gain.

Structural modifications of the serotonin 5-HT7 receptor agonist N-(4-cyanophenylmethyl)-4-(2-biphenyl)-1-piperazinehexanamide (LP-211) to improve in vitro microsomal stability: A case study

The 5-HT7 serotonin receptor is revealing a promising target for innovative therapeutic strategies of neurodevelopmental and neuropsychiatric disorders. Here, we report the synthesis of thirty long-chain arylpiperazine analogs of the selective and brain penetrant 5-HT7 receptor agonist LP-211 (1) designed to enhance stability towards microsomal oxidative metabolism. Commonly used medicinal chemistry strategies were used (i.e., reduction of overall lipophilicity, introduction of electron-withdrawing groups, blocking of potential vulnerable sites of metabolism), and in vitro microsomal stability was tested. The data showed that the adopted design strategy does not directly translate into improvements in stability. Instead, the metabolic stability of the compounds was related to the presence of specific substituents in well-defined regions of the molecule. The collected data allowed for the construction of a machine learning model that, in a given chemical space, is able to describe and quantitatively predict the metabolic stability of the compounds. The majority of the synthesized compounds maintained high affinity for 5-HT7 receptors and showed selectivity towards 5-HT6 and dopamine D2 receptors and different selectivity for 5-HT1A and α1 adrenergic receptors. Compound 50 showed 3-fold higher in vitro stability towards oxidative metabolism than 1 and was able to stimulate neurite outgrowth in neuronal primary cultures through the 5-HT7 receptor in a shorter time and at a lower concentration than the agonist 1. A preliminary disposition study in mice revealed that compound 50 was metabolically stable and was able to pass the blood-brain barrier, thus representing a new tool for studying the pharmacotherapeutic potential of 5-HT7 receptor in vivo.

Aripiprazole loaded poly(caprolactone) nanoparticles: Optimization and in vivo pharmacokinetics

In the present investigation, a Quality by Design strategy was applied for formulation and optimization of aripiprazole (APZ) loaded PCL nanoparticles (APNPs) using nanoprecipitation method keeping entrapment efficiency (%EE) and particle size (PS) as critical quality attributes. Establishment of design space was done followed by analysis of its robustness and sensitivity. Characterization of optimized APNPs was done using DSC, FT-IR, PXRD and TEM studies and was evaluated for drug release, hemocompatibility and nasal toxicity. PS, zeta potential and %EE of optimized APNPs were found to be 199.2±5.65nm, -21.4±4.6mV and 69.2±2.34% respectively. In vitro release study showed 90±2.69% drug release after 8h. Nasal toxicity study indicated safety of developed formulation for intranasal administration. APNPs administered via intranasal route facilitated the brain distribution of APZ incorporated with the AUC0→8 in rat brain approximately 2 times higher than that of APNPs administered via intravenous route. Increase in Cmax was observed which might help in dose reduction along with reduction in dose related side effects. The results of the study indicate that intranasally administered APZ loaded PCL NPs can potentially transport APZ via nose to brain and can serve as a non-invasive alternative for the delivery of APZ to brain.

Extrapyramidal side-effects of low-dose aripiprazole in an 11-year-old child

Partial agonism of D2 and 5-HT1A receptors accounts for the low incidence of extrapyramidal side-effects of aripiprazole. Extrapyramidal symptoms (EPS) during treatment with therapeutical doses of aripiprazole have been reported in adults and children. To the best of our knowledge, no cases of EPS with low doses (5 mg) have been reported until now. In this article, we present an 11-year-old child who developed EPS on low doses (5 mg) aripiprazole. This case emphasizes the need for careful surveillance for the development of EPS in patients treated even with low doses of aripiprazole.

Blonanserin Augmentation for Treatment-Resistant Somatic Symptom Disorder: A Case Series

The augmentation of selective serotonin reuptake inhibitors with antipsychotics that have a high dopamine-receptor-D2 affinity may be effective in treatment-resistant obsessive-compulsive disorder and somatic symptom disorder, which is similar to illness anxiety disorder. Blonanserin, a novel antipsychotic developed in Japan, has a high affinity for the D2 receptor and weak or very little affinity for other receptors. This article presents two case studies that demonstrate the efficacy of blonanserin augmentation for treatment-resistant somatic symptom disorder. Two patients with treatment-resistant somatic symptom disorder were prescribed concomitant use of blonanserin. Augmentation with blonanserin resulted in the remarkable amelioration of all symptoms. Sedative adverse drug reactions produced by aripiprazole were improved after replacing it with blonanserin. Blonanserin is effective in treatment-resistant somatic symptom disorder. Furthermore, compared with aripiprazole, blonanserin is more likely to result in medication adherence in patients with somatic symptom disorder because it reduced adverse drug reactions.

Simultaneous Use of Intravenous Lipid Emulsion and Plasma Exchange Therapies in Multiple Drug Toxicity

OBJECTIVE

The aim of this study was to highlight the use of combined intravenous lipid emulsion (ILE) and plasma exchange (PE) therapies in multidrug toxicity.

CLINICAL PRESENTATION AND INTERVENTION

A 45-year-old woman who attempted suicide by ingesting large quantities of amisulpride (28 g), diazepam (250 mg), valsartan (2,240 mg), aripiprazole (45 mg) and paliperidone (21 mg) was taken to the hospital of Adnan Menderes University School of Medicine. Upon arrival, she exhibited signs of cardiotoxicity and severe depression of the central nervous and respiratory systems. She was treated successfully with ILE for 4 h and PE therapy for 36 h, consecutively. She was discharged on the fourth day of hospitalization having fully recovered.

CONCLUSION

The patient was successfully treated with the combination of ILE and PE.

Aripiprazole and Risperidone for Treatment of Methamphetamine-Associated Psychosis in Chinese Patients

We evaluated tolerability and efficacy of aripiprazole and risperidone for treatment of methamphetamine (METH) associated psychotic symptoms in China. Patients with acute METH-associated psychotic symptoms (N=42) and with Positive and Negative Syndrome Scale (PANSS) total score between 60 and 120 were randomized to aripiprazole (initial dose 5-10mg per day followed by flexible doses 5-15 mg per day) or risperidone (initial dose 2-4 mg per day followed by flexible doses 4-6 mg per day) from day 3 to 25 of inpatient hospital stay. Outcome measures included PANSS and Clinical Global Impressions-Severity of Illness scale (CGI-S), METH craving Visual Analogue Scale (VAS), Simpson Angus Scale (SAS), Barnes Assessments Akathasia Rating Scale (BARS), and self-reported adverse effects evaluated during treatment. Retention was evaluated using Kaplan-Meier survival analysis and the MIXED models procedure was used to compare the groups on measures of psychotic and extra-pyramidal symptoms. Patients in both aripiprazole and risperidone groups showed statistically significant reductions in psychotic symptomatology from baseline during treatment (p<0.001) with no statistically significant differences between the treatment groups (p=0.73 and p=0.15, respectively). Risperidone-treated patients reported significantly greater METH craving reductions (p<0.001). Overall, 71% of patients completed the entire study, but the aripiprazole group had a significantly lower retention than the risperidone group (p=0.007), primarily due to medication related adverse effects. Aripiprazole-treated patients also had significantly more akathisia (p=0.03) and agitation (p=0.02) than risperidone-treated patients. Patients in both groups who tolerated their medications and completed the entire study achieved comparable reductions of psychotic symptoms.

Facile Synthesis and Properties of 2-λ(5)-Phosphaquinolines and 2-λ(5)-Phosphaquinolin-2-ones

Treatment of 2-ethynylanilines with P(OPh)3 gives either 2,2-diphenoxy-2-λ(5)-phosphaquinolines or 2-phenoxy-2-λ(5)-phosphaquinolin-2-ones under transition-metal-free conditions. This reaction offers access to an underexplored heterocycle, which opens up the study of the fundamental nature of the N=P(V) double bond and its potential for delocalization within a cyclic π-electron system. This heterocycle can serve as a carbostyril mimic, with application as a bioisostere for pharmaceuticals based on the 2-quinolinone scaffold. It also holds promise as a new fluorophore, since initial screening reveals quantum yields upwards of 40%, Stokes shifts of 50-150 nm, and emission wavelengths of 380-540 nm. The phosphaquinolin-2-ones possess one of the strongest solution-state dimerization constants for a D-A system (130 M(-1)) owing to the close proximity of a strong acceptor (P=O) and a strong donor (phosphonamidate N-H), which suggests that they might hold promise as new hydrogen-bonding hosts for optoelectronic sensing.

The VA augmentation and switching treatments for improving depression outcomes (VAST-D) study: Rationale and design considerations

Because two-thirds of patients with Major Depressive Disorder do not achieve remission with their first antidepressant, we designed a trial of three "next-step" strategies: switching to another antidepressant (bupropion-SR) or augmenting the current antidepressant with either another antidepressant (bupropion-SR) or with an atypical antipsychotic (aripiprazole). The study will compare 12-week remission rates and, among those who have at least a partial response, relapse rates for up to 6 months of additional treatment. We review seven key efficacy/effectiveness design decisions in this mixed "efficacy-effectiveness" trial.

The effect of resveratrol on pharmacokinetics of aripiprazole in vivo and in vitro

1. The objective of this study were to investigate the effect of orally administered resveratrol on the pharmacokinetics of aripiprazole (APZ) in rat, and the inhibitory effects of resveratrol on APZ dehydrogenation activity in liver microsomes and human cytochrome P450 3A4 and 2D6. 2. Twenty-five healthy male Sprague-Dawley rats were randomly divided into five groups: A (control group), B (multiple dose of 200 mg/kg resveratrol), C (multiple dose of 100 mg/kg resveratrol), D (a single dose of 200 mg/kg resveratrol) and E (a single dose of 100 mg/kg resveratrol). A single dose of 3 mg/kg APZ administered orally 30 min after administration of resveratrol. In addition, CYP2D6*1, CYP3A4*1, human and rat liver microsomes were performed to determine the effect of resveratrol on the metabolism of APZ in vitro. 3. The multiple dose of 200 or 100 mg/kg resveratrol significantly increased the AUC and Cmax of APZ. The resveratrol also obviously decreased the CL, but without any significant difference on t1/2 in vivo. On the other hand, resveratrol showed inhibitory effect on CYP3A4*1, CYP2D6*1, human and rat microsomes, the IC50 of resveratrol was 6.771, 87.87, 45.11 and 35.59 μmol l(-1), respectively. 4. Those results indicated more attention should be paid when APZ was administrated combined with resveratrol.

Atypical neuroleptic malignant syndrome in patients treated with aripiprazole and clozapine: a case-series study and short review

OBJECTIVES

Neuroleptic malignant syndrome (NMS) requires emergency treatment and can be fatal. Combined aripiprazole and clozapine therapy is rarely used in clinical settings, and NMS related this combination still lacks evaluation. Herein, we present two cases of atypical NMS treated with aripiprazole and clozapine.

METHODS

Case 1 was a schizophrenic male with a history of NMS under treatment with aripiprazole 20 mg. He was hospitalized and maintained with aripiprazole 5 mg and clozapine 225 mg. On the 25th day, atypical NMS occurred with rigidity, elevated creatine kinase, and stupor, which subsided with supportive therapy. He was discharged under treatment with aripiprazole 15 mg and fluoxetine 60 mg. Case 2 was a female with schizoaffective disorder without a history of NMS. She was hospitalized and maintained with clozapine 50 mg and aripirazole 30 mg. On the 11th day, atypical NMS occurred with mild fever, delirium, and rigidity, which subsided under supportive therapy.

RESULTS AND CONCLUSIONS

Our cases highlight the atypical features of NMS in patients being treated with combined ari-piprazole and clozapine. Consciousness change, modest elevation of creatine kinase, and leukocytosis were the most consistent findings; hyperthermia accounts for only some of the cases. This is a reminder of the importance of earlier detection of the soft signs and atypical features of NMS under this combined treatment.

Lack of correlation between the steady-state plasma concentrations of aripiprazole and haloperidol in Japanese patients with schizophrenia

BACKGROUND

Both aripiprazole and haloperidol have been used in the treatment of schizophrenia, and are metabolized by the cytochrome P450 (CYP) 2D6 and CYP3A4. The authors studied the correlations between the steady-state plasma concentrations (Css) of aripiprazole and its active metabolite, dehydroaripiprazole, and those of haloperidol in 19 Japanese patients with schizophrenia, together with the effects of CYP2D6 genotypes on the steady-state kinetics of these compounds.

METHODS

All the patients received first 24 mg/d of aripiprazole for 3 weeks and later received 6 mg/d of haloperidol for 2 weeks. Blood samplings were performed at least 2 weeks after the initiation of each treatment. The Css values of aripiprazole and dehydroaripiprazole were measured using liquid chromatography with mass spectrometric detection, and those of haloperidol were measured by using an enzyme immunoassay. CYP2D6 genotypes were determined by using polymerase chain reaction analysis.

RESULTS

None of the correlations between the Css of aripiprazole (r = 0.286) or the sum of aripiprazole plus dehydroaripiprazole (r = 0.344) and those of haloperidol were significant. The mean Css of aripiprazole was significantly higher (P < 0.05) in the subjects with 1 *10 allele of CYP2D6 (n = 6) than in those with no mutated alleles (n = 13), whereas there were no significant differences in those of haloperidol between the 2 groups.

CONCLUSIONS

This study suggests that the Css of aripiprazole and that of aripiprazole plus dehydroaripiprazole do not correlate with that of haloperidol in the same individual, because of the greater involvement of CYP2D6 in the metabolism of aripiprazole than in that of haloperidol.

Aripiprazole Induced Acute Transient Bilateral Myopia: A Case Report

BACKGROUND

Aripiprazole is an atypical antipsychotic drug. Acute transient myopia is a rare response to systemic medication. Unspecified ocular side effects of aripiprazole have rarely been reported. To the best of our knowledge, only 3 cases of aripiprazole induced myopia and diplopia have been reported in the literature. The aim of this article is to present a case of aripiprazole-induced acute transient myopia.

CASE REPORT

A 30 year-old woman underwent treatment for 5 days with aripiprazole and presented with bilateral painless blurred vision. The patient's uncorrected visual acuity was 2/10 in both eyes and her best corrected visual acuity was 10/10 in both eyes with a refractive error of -3.00 diopters using a standard Snellen chart. Adding 2 mgs of biperiden a day to her treatment regimen decreased her blurred vision symptoms. After discontinuation of aripiprazole treatment and cross-switching to Paliperidon palmitate (75 mg/month) her blurred vision completely resolved. The same side effect did not re-occur when checked on her 6-month follow up.

CONCLUSION

Ophthalmologists as well as psychiatrists must be aware of this myopic shift and should also ask these patients about medicine usage, especially aripiprazole. Ophthalmologists should consult the prescribing psychiatrist and stop the drug immediately to reverse this temporary condition.

Effects of genetic polymorphisms of CYP2D6, CYP3A5, and ABCB1 on the steady-state plasma concentrations of aripiprazole and its active metabolite, dehydroaripiprazole, in Japanese patients with schizophrenia

BACKGROUND

We studied the effects of various factors, including genetic polymorphisms of the cytochrome P450 (CYP) 2D6, CYP3A5, and ABCB1, age, gender, and smoking habit on the steady-state plasma concentrations of aripiprazole and its active metabolite, dehydroaripiprazole, in 89 patients with schizophrenia (46 males, 43 females).

METHODS

All patients had been receiving fixed doses of aripiprazole for at least 2 weeks. The daily doses were 24 mg (n = 56) and 12 mg (n = 33). No other drugs except biperiden and flunitrazepam were coadministered. Plasma concentrations of aripiprazole and dehydroaripiprazole were measured using liquid chromatography with mass-spectrometric detection. The CYP2D6 (CYP2D6*5, CYP2D6*10, and CYP2D6*14), CYP3A5 (CYP3A5*3), and ABCB1 (C3435T and G2677T/A) genotypes were identified by PCR analyses.

RESULTS

The mean concentration/dose ratios of aripiprazole and the sum of aripiprazole and dehydroaripiprazole were significantly higher in patients with 1 (P < 0.01 and P < 0.01) or 2 (P < 0.001 and P < 0.05) mutated alleles for CYP2D6 than in those without mutated alleles. No differences were found in the values of dehydroaripiprazole among CYP2D6 genotypes. There were no differences in the values of aripiprazole, dehydroaripiprazole, and the sum of the 2 compounds among CYP3A5 or the 2 ABCB1 variants. Multiple regression analyses including these polymorphisms, age, gender, and smoking habit showed that only the number of mutated alleles for CYP2D6 was correlated with mean concentration/dose ratios of aripiprazole [standardized partial correlation coefficients (beta) = 0.420, P < 0.001] and the sum of the 2 compounds (standardized beta = 0.335, P < 0.01).

CONCLUSIONS

The findings of this study suggest that CYP2D6 genotypes play an important role in controlling steady-state plasma concentrations of aripiprazole and the sum of aripiprazole and dehydroaripiprazole in Asian subjects, whereas CYP3A5 and ABCB1 genotypes seemed unlikely to have an impact.

Quetiapine versus aripiprazole in the management of schizophrenia

OBJECTIVES

Current evidence supports the use of various second-generation antipsychotics for pharmacotherapy of schizophrenia. While in a systematic review, generally no difference in efficacy was found between atypical antipsychotics, other studies have found quetiapine less effective than aripiprazole. This article reviews the efficacy and tolerability of aripiprazole versus quetiapine in the context of recommended management strategies for schizophrenia.

METHOD

Fifty female inpatients, meeting the diagnosis of schizophrenia, were randomly entered into two groups (n = 25 in each group) to participate in a 12-week, double-blind study for random assignment to quetiapine or aripiprazole. The primary outcome measures were Scale for Assessment of Positive Symptoms and Scale for Assessment of Negative Symptoms. The schedule for Assessment of Insight (SAI), Clinical Global Impressions Severity Scale (CGI-S) and the Simpson Angus Scale (SAS) were also used as secondary measures.

RESULTS

Both quetiapine and aripiprazole showed significant effectiveness in the improvement of positive symptoms. The effectiveness for negative symptoms was also noteworthy with both drugs, although not to a significant level during this study. In addition, significant improvement was found on assessment with CGI-S and SAI for quetiapine and aripiprazole. SAS did not show any important increment in extrapyramidal side effects at the end of the examination.

CONCLUSION

According to the findings, quetiapine and aripiprazole had similar effectiveness and tolerability with respect to management of schizophrenia.

Efficacy and safety of aripiprazole augmentation of clozapine in schizophrenia: a systematic review and meta-analysis of randomized-controlled trials

Limited options are available for clozapine-resistant schizophrenia and intolerable side effects of clozapine. We conducted a systematic review of randomized-controlled trials (RCTs) to determine the efficacy and safety of aripiprazole augmentation of clozapine for schizophrenia. Electronic databases searched included PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science. This review synthesized the data of four short-term (8-24 weeks), placebo-controlled trials (N = 347). The overall relative risk (RR, 95% confidence interval) of discontinuation rates was not significantly different between groups (RR = 1.41, 95% CI = 0.78 to 2.56). The pooled standardized mean differences (SMDs, 95% CIs) (Z-test; number of study; I(2)-index) suggested trends of aripiprazole augmentation benefits on overall psychotic [-0.40 (-0.87 to 0.07) (n = 3; Z = 1.68, p = 0.09; I(2) = 68%)], positive [-1.05 (-2.39 to 0.29) (n = 3; Z = 1.54, p = 0.12; I(2) = 94%)], and negative [-0.36 (-0.77 to 0.05) (n = 3; Z = 1.74, p = 0.08; I(2) = 54%)] symptoms. Despite of no benefit on three cardiometabolic indices (i.e., fasting plasma glucose, triglyceride, and high-density lipoprotein), aripiprazole augmentation was superior for weight change with a mean difference (95% CI) of -1.36 kg (-2.35 to -0.36) (n = 3; Z = 2.67, p = 0.008; I(2) = 39%) and LDL-cholesterol with a mean difference of -11.06 mg/dL (-18.25 to -3.87) (n = 3; Z = 3.02, p = 0.003; I(2) = 31%). Aripiprazole augmentation was not correlated with headache and insomnia but significantly associated with agitation/akathesia (RR = 7.59, 95% CI = 1.43 to 40.18) (n = 3; Z = 2.38, p = 0.02; I(2) = 0%) and anxiety (RR = 2.70, 95% CI = 1.02 to 7.15) (n = 1; Z = 2.00, p = 0.05). The limited short-term data suggested that aripiprazole augmentation of clozapine can minimize the cardiometabolic risk, causes agitation/akathesia, and may be effective in attenuating psychotic symptoms.

Effects of switching from olanzapine to aripiprazole on the metabolic profiles of patients with schizophrenia and metabolic syndrome: a double-blind, randomized, open-label study

BACKGROUND

Patients with schizophrenia suffer high rates of metabolic derangements on some antipsychotic medications that predispose them to cardiovascular diseases. Keeping this fact in mind, we planned this open-label study to see the effect on various metabolic parameters after switching stable schizophrenia subjects, who had developed metabolic syndrome on olanzapine, to aripiprazole.

METHODS

Sixty-two patients with schizophrenia who were stable on olanzapine and were fulfilling modified National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP-III) criteria for the presence of metabolic syndrome were enrolled on the study. Patients were randomly assigned either to switch to aripiprazole or to stay on olanzapine, on a 1:1 basis. Cross-tapering over a period of 1 month was done while switching patients to aripiprazole. Laboratory assessment for metabolic parameters was done at baseline, 8 weeks, and 24 weeks after enrollment; efficacy assessment was done using the Positive and Negative Syndrome Scale (PANSS) at baseline and 24 weeks, the Clinical Global Impressions severity subscale (CGI-S) at baseline, and the Clinical Global Impressions improvement subscale (CGI-I) at 24 weeks.

RESULTS

All parameters of metabolic syndrome (waist circumference, blood pressure, triglyceride level, fasting blood glucose, and high-density lipoprotein cholesterol) kept deteriorating in the stay group, compared with a continuous improvement in the switch group over time. At the end of the study, 26 patients (100%) from the stay group and 15 patients (42.8%) from switch group met the modified NCEP ATP-III criteria for presence of metabolic syndrome (P<0.001). There were no statistically significant differences between groups in psychopathology changes as measured by the PANSS total score and CGI-I scores.

CONCLUSION

Clinically stable patients with schizophrenia who are taking olanzapine and who have evidence of metabolic syndrome can be successfully switched to aripiprazole, with improvement in various parameters of metabolic syndrome and without any significant change in efficacy measures.

Antipsychotic treatment for children and adolescents with schizophrenia spectrum disorders: protocol for a network meta-analysis of randomised trials

INTRODUCTION

Antipsychotic treatment in early-onset schizophrenia (EOS) lacks a rich evidence base, and efforts to rank different drugs concerning their efficacy have not proven any particular drug superior. In contrast to the literature regarding adult-onset schizophrenia (AOS), comparative effectiveness studies in children and adolescents are limited in number and size, and only a few meta-analyses based on conventional methodologies have been conducted.

METHODS AND ANALYSES

We will conduct a network meta-analysis of all randomised controlled trials (RCTs) that evaluate antipsychotic therapies for EOS to determine which compounds are efficacious, and to determine the relative efficacy and safety of these treatments when compared in a network meta-analysis. Unlike a contrast-based (standard) meta-analysis approach, an arm-based network meta-analysis enables statistical inference from combining both direct and indirect comparisons within an empirical Bayes framework. We will acquire eligible studies through a systematic search of MEDLINE, the Cochrane Central Registry of Controlled Trials, Clinicaltrials.gov and Centre for Reviews and Dissemination databases. Eligible studies should randomly allocate children and adolescents presenting with schizophrenia or a related non-affective psychotic condition to an intervention group or to a control group. Two reviewers will-independently and in duplicate-screen titles and abstracts, complete full text reviews to determine eligibility, and subsequently perform data abstraction and assess risk of bias of eligible trials. We will conduct meta-analyses to establish the effect of all reported therapies on patient-relevant efficacy and safety outcomes when possible.

ETHICS AND DISSEMINATION

No formal ethical procedures regarding informed consent are required as no primary data collection is undertaken. The review will help facilitate evidence-based management, identify key areas for future research, and provide a framework for conducting large systematic reviews combining direct and indirect comparisons. The study will be disseminated by peer-reviewed publication and conference presentation.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42013006676.

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.

Neurocognitive effects of aripiprazole in adolescents and young adults with schizophrenia

BACKGROUND

The use of aripiprazole has been associated with a positive influence on mood and improved cognitive skills and social interactions; however, studies of its effects on young schizophrenic patients have been limited to active symptoms.

AIMS

This prospective, open-label study investigated the neurocognitive effects of aripiprazole in adolescents and young adults with first and repeated episodes of schizophrenia.

METHODS

Twenty-three of 42 schizophrenic outpatients aged 12-26 completed a trial of aripiprazole, and its efficacy was determined using the Brief Psychiatric Rating Scale (BPRS), Clinical Global Impressions Severity (CGI-S) and WHO Quality of Life (WHOQOL) scales. Cognitive function was measured with the Cognitive Performance Test (CPT) and Wisconsin Card Sorting Test (WCST) at 4, 12 and 24 weeks of treatment.

RESULTS

Results showed statistically significant improvements in BPRS, CGI-S and WHOQOL scores in certain (but not all) subcategories of cognitive measures including CPT detectability and total errors and perseverative errors on the WCST. There were few adverse side-effects.

CONCLUSIONS

Psychotic symptoms and cognitive skills improved during treatment with aripiprazole in adolescents and young adults with schizophrenia. Patients with first psychotic episodes did better than did those with repeat episodes.

Steady-state pharmacokinetic properties of aripiprazole 10 mg PO g12h in Han Chinese adults with schizophrenia: A prospective, open-label, pilot study

OBJECTIVES

The aims of this study were to investigate the pharmacokinetic (PK) properties of aripiprazole in the steady state in Han Chinese adults with schizophrenia and to compare them between Han Chinese and white populations described in the literature.

METHODS

This prospective, open4abel, pilot study was conducted at the Mental Health Institute, Xiang-ya Second Hospital, Central South University, Changsha, China. Male and female hospitalized patients aged 18 to 45 years diagnosed with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)-defined schizophrenia, with a Positive and Negative Syndrome Scale (PANSS) total score ⩾60 (indicating schizophrenia of at least mild severity) were eligible. On study days 1 and 2, patients were pretreated with aripiprazole 10 mg PO QD, followed by 10 mg g12h on days 3 to 21. Blood samples were drawn for analysis on day 21 before dosing and 1, 3, 4, 5, 12, 24, 48, 72, 96, 144, and 192 hours after the morning dosing of aripiprazole on day 21. Patients received low-dose (25-100 mg/d) clozapine on day 25 until day 28. The samples were assessed using high-performance liquid chromatography-mass spectrometry and compartment model analysis for aripiprazole. PK properties included mean residence time (MRT) steady-state Cmax (Css max), time to Css max (Tmax), elimination t/12, apparent oral clearance (CL/F), and apparent volume of distribution (V/F). Adverse effects were monitored using physical examination (including vital sign measurements), electrocardiography, electroencephalography, and clinical laboratory testing (including biochemistry, hematology, and urinalysis) at baseline and at the end of the study. Patients were asked about adverse events on days 1 to 7 and at random intervals thereafter. Patients were also instructed to report any spontaneous symptoms they experienced.

RESULTS

Twelve patients were enrolled (6 men, 6 women; mean [SD] age, 26.1 [7.0] years; mean [SD] weight, 56.6 [9.0] kg; mean [SD] PANSS score, 116.8 [12.2]). Aripiprazole exhibited linear kinetic characteristics on a 2-compartment model. After multiple oral doses (10 mg g12h), the mean (SD) t1/2, Css max, Tmax, MRT, V/F, and CL/F were 62.2 (9.0) hours, 557.3 (135.5) ng/mL, 2.6 (1.1) hours, 84.5 (11.2) hours, 173 (48) L, and 1.9 (0.5) L/h, respectively. In Chinese patients, the t/12 values were numerically similar (62.2 [9.0] vs 68.1 [22.9] hours); Css max values were numerically higher (557.3 [135.5] vs 393 [181 ] ng/mL); and V/F and CL/F values were numerically lower (V/F: 173 [48] vs 196 [66] L; CL/F: 1.9 [0.5] vs 3.4 [1.6] L/h) compared with healthy white male volunteers. Adverse effects were mild to moderate: lightheadedness (5 of 12 patients), somnolence (3), tachycardia (3), hypodynamia (2), and extrapyramidal symptoms (EPS) (1). The EPS (convulsive movement of the muscles related to the larynx) led to one patient's discontinuation of the study.

CONCLUSIONS

In this small pilot study of the PK properties of aripiprazole 10 mg PO g12h in Han Chinese patients with schizophrenia, the mean t1/2 value was numerically similar to that previously reported in a population of healthy white male volunteers. However, the mean Css max value was numerically higher, and V/F and CL/F values were numerically lower, compared with those in healthy white male volunteers.

Aripiprazole: a review of its use in the treatment of manic episodes in adolescents with bipolar I disorder

Aripiprazole (Abilify(®)) is an atypical antipsychotic that is widely used in the treatment of psychiatric conditions. Unlike other currently available atypical antipsychotics that primarily have varying degrees of dopamine D2 receptor antagonism, aripiprazole is a partial agonist at D2 and serotonin 5-HT1A receptors, which may explain differences in tolerability profiles. Recently in the EU, oral aripiprazole 10 mg once daily for 12 weeks was approved for the treatment of moderate to severe manic episodes in adolescents (aged ≥13 years) with bipolar I disorder. Approval was based on a phase 3, 30-week US trial in children and adolescents with bipolar I disorder experiencing manic or mixed episodes. Using trial data together with ancillary analyses, the European Medicines Agency concluded that aripiprazole 10 mg once daily for 12 weeks was effective in reducing symptoms of mania, but because of the high drop-out rate, efficacy over 30 weeks of treatment was not proven. Aripiprazole was generally well tolerated in the phase 3 trial. Ancillary analyses indicated that tolerability was less favourable in younger (10-12 years) than in older (≥13 years) subjects, and less favourable with the higher (30 mg/day) than the lower dosage (10 mg/day). The drug is associated with sedation, weight gain and extrapyramidal symptoms (EPS), although the incidence of EPS over 12 weeks was not significantly different between aripiprazole 10 mg/day and placebo. Data comparing the use of atypical antipsychotics in the treatment of mania in adolescents with bipolar I disorder are limited, but evidence shows that aripiprazole provides a valuable additional therapeutic option for use in this population.

Aripiprazole in an animal model of chronic alcohol consumption and dopamine D₂ receptor occupancy in rats

BACKGROUND

Epidemiologic studies and clinical assessment of schizophrenic population have revealed a high incidence of overlap between schizophrenia and addictive disorders.

OBJECTIVE

The aim of the present investigation was to study the effect of aripiprazole in a preclinical animal model of chronic alcohol self-administration (CASA) and also to evaluate the influence of CASA on plasma pharmacokinetics and dopamine D₂ receptor (D₂R) occupancy in rats.

METHODS

The effect of oral administration of aripiprazole (1, 3, and 10 mg/kg) on 4% alcohol intake in CASA was studied for a period of 45 min after a post-dosing interval of 60 min. Brain penetration, pharmacokinetics, and D₂R occupancy of aripiprazole were evaluated in normal and CASA rats.

RESULTS

Aripiprazole reduced alcohol consumption in CASA rats by 13, 28, and 86% at 1, 3, and 10 mg/kg, respectively, and the effect reached statistical significance at 10 mg/kg (p < .01). At this behavioral effective dose, a decrease (75%) in total plasma apparent clearance and an increase in oral area under the concentration-time curve (3.98-fold) and bioavailability (3.50-fold) of aripiprazole was observed in CASA rats. Striatal D₂R occupancy and brain exposure of aripiprazole were significantly higher (∼twofold) in CASA rats when compared to normal rats (p < .01).

CONCLUSION

Chronic alcohol intake results in a significant increase in exposure of aripiprazole in plasma and brain and striatal D₂R occupancy.

SCIENTIFIC SIGNIFICANCE

Chronic alcohol intake would increase aripiprazole exposure, thus aripiprazole dose might have to be decreased (assuming this same phenomenon occurs in humans).

Pomaglumetad Methionil (LY2140023 Monohydrate) and Aripiprazole in Patients with Schizophrenia: A Phase 3, Multicenter, Double-Blind Comparison

We tested the hypothesis that long-term treatment with pomaglumetad methionil would demonstrate significantly less weight gain than aripiprazole in patients with schizophrenia. In this 24-week, multicenter, randomized, double-blind, Phase 3 study, 678 schizophrenia patients were randomized to either pomaglumetad methionil (n = 516) or aripiprazole (n = 162). Treatment groups were also compared on efficacy and various safety measures, including serious adverse events (SAEs), discontinuation due to adverse events (AEs), treatment-emergent adverse events (TEAEs), extrapyramidal symptoms (EPS), and suicide-related thoughts and behaviors. The pomaglumetad methionil group showed significantly greater weight loss at Week 24 (Visit 12) compared with the aripiprazole group (-2.8 ± 0.4 versus 0.4 ± 0.6; P < 0.001). However, change in Positive and Negative Syndrome Scale (PANSS) total scores for aripiprazole was significantly greater than for pomaglumetad methionil (-15.58 ± 1.58 versus -12.03 ± 0.99; P = 0.045). The incidences of SAEs (8.2% versus 3.1%; P = 0.032) and discontinuation due to AEs (16.2% versus 8.7%; P = 0.020) were significantly higher for pomaglumetad methionil compared with aripiprazole. No statistically significant differences in the incidence of TEAEs, EPS, or suicidal ideation or behavior were noted between treatment groups. In conclusion, long-term treatment with pomaglumetad methionil resulted in significantly less weight gain than aripiprazole. This trial is registered with ClinicalTrials.gov NCT01328093.

Effects of repeated treatment with the dopamine D2/D3 receptor partial agonist aripiprazole on striatal D2/D3 receptor availability in monkeys

RATIONALE

Chronic treatment with dopamine (DA) receptor agonists and antagonists can differentially affect measures of DA D2/D3 receptor number and function, but the effects of chronic treatment with a partial D2/D3 receptor agonist are not clear.

OBJECTIVE

We used a within-subjects design in male cynomolgus monkeys to determine the effects of repeated (17-day) treatment with the D2/D3 receptor partial agonist aripiprazole (ARI; 0.03 mg/kg and 0.1 mg/kg i.m.) on food-reinforced behavior (n = 5) and on D2/D3 receptor availability as measured with positron emission tomography (PET; n = 9).

METHODS

Five monkeys responded under a fixed-ratio 50 schedule of food reinforcement and D2/D3 receptor availability was measured before and 4 days after ARI treatment using PET and the D2/D3 receptor-selective radioligand [18F]fluoroclebopride (FCP). Four additional monkeys were studied using [11C]raclopride and treated sequentially with each dose of ARI for 17 days.

RESULTS

ARI decreased food-maintained responding with minimal evidence of tolerance. Repeated ARI administration increased FCP and raclopride distribution volume ratios (DVRs) in the caudate nucleus and putamen in most monkeys, but decreases were observed in monkeys with the highest baseline DVRs.

CONCLUSIONS

The results indicate that repeated treatment with a low-efficacy DA receptor partial agonist produces effects on brain D2/D3 receptor availability that are qualitatively different from those of both high-efficacy receptor agonists and antagonists, and suggest that the observed individual differences in response to ARI treatment may reflect its partial agonist activity.

Active metabolites as antidepressant drugs: the role of norquetiapine in the mechanism of action of quetiapine in the treatment of mood disorders

Active metabolites of some antipsychotic drugs exhibit pharmacodynamic and pharmacokinetic properties that may be similar to or differ from the original compound and that can be translated by a different profile of responses and interactions to clinical level. Some of these antipsychotics' active metabolites might participate in mechanisms of antidepressant activity, as m-chlorophenylpiperazine (aripiprazole), 9-OH-risperidone and norquetiapine. Norquetiapine exhibits distinct pharmacological activity from quetiapine and plays a fundamental role in its antidepressant efficacy. In this review, we analyze the differential pharmacological aspects between quetiapine and norquetiapine, both from the pharmacokinetic and pharmacodynamic perspectives (affinity for dopaminergic, noradrenegic, and/or serotonergic receptors, etc.), as well as differential neuroprotective role. The pharmacological differences between the two drugs could explain the differential clinical effect, as well as some differences in tolerability profile and drug interactions. The available data are sufficient to arrive at the conclusion that antidepressant activity of quetiapine is mediated, at least in part, by the active metabolite norquetiapine, which selectively inhibits noradrenaline reuptake, is a partial 5-HT1A receptor agonist, and acts as an antagonist at presynaptic α2, 5-HT2C, and 5-HT7 receptors.

Safety and pharmacokinetics of atypical antipsychotics in children and adolescents

Pediatric behavioral and affective disorders often require antipsychotic therapy, in combination with psychotherapeutic interventions, for their treatment and stabilization. Although pharmacotherapy can include either typical or atypical antipsychotics, the latter are generally preferred because of their apparently lower risk of adverse effects. Recent controlled trials have demonstrated the efficacy of some of these agents (including aripiprazole, clozapine, olanzapine, paliperidone, quetiapine, risperidone, ziprasidone) in adolescent schizophrenia and children or adolescent bipolar mania, or to treat severe aggression and self-injury in the context of autism in children and adolescents. Although few studies have systematically monitored their short- and, more importantly, long-term safety, current evidence indicates that sedation, hyperprolactinemia, and metabolic abnormalities such as excess weight gain, diabetes, and related cardiovascular effects were clinically relevant adverse effects in young patients, with the individual agents differing in their propensity to induce these effects. When prescribing antipsychotics for children and adolescents, physicians should therefore be aware of the specific adverse effect profiles and patients should be closely monitored for the short- and long-term development of adverse events. In pediatric patients, the starting dose, titration plan, and maintenance dose of antipsychotics must be based on their pharmacokinetics and metabolism, as in adults. Because there are significant individual differences in drug and active metabolite(s) pharmacokinetics and metabolism, which may be further affected by a number of confounding factors (including demographic variables, phenotype and drug interactions), therapeutic drug monitoring may be a valid tool for individualizing dosage, but its interpretation should also take account of changes in pharmacodynamic sensitivity with the development during childhood and adolescence.

Aripiprazole-montmorillonite: a new organic-inorganic nanohybrid material for biomedical applications

Poor aqueous solubility and the unpleasant taste of aripiprazole (APZ) have been recurring problems, owing to its low bioavailability and low patient tolerance, respectively. Herein, we prepared a nanohybrid system that was based on a bentonite clay material, montmorillonite (MMT), which could both mask the taste and enhance the solubility of APZ (i.e., APZ-MMT). To further improve the efficacy of this taste masking and drug solubility, APZ-MMT was also coated with a cationic polymer, polyvinylacetal diethylamino acetate (AEA). In vitro dissolution tests at neutral pH showed that the amount of drug that was released from the AEA-coated APZ-MMT was greatly suppressed (<1%) for the first 3 min, thus suggesting that AEA-coated APZ-MMT has strong potential for the taste masking of APZ. Notably, in simulated gastric juice at pH 1.2, the total percentage of APZ that was released within the first 2 h increased up to 95% for AEA-coated APZ-MMT. Furthermore, this in vitro release profile was also similar to that of Abilify®, a commercially available medication. In vivo experiments by using Sprague-Dawley rats were also performed to compare the pharmacokinetics of AEA-coated APZ-MMT and Abilify®. AEA-coated APZ-MMT exhibited about 20% higher systemic exposure of APZ and its metabolite, dehydro-APZ, compared with Abilify®. Therefore, a new MMT-based nanovehicle, which is coated with a cationic polymer, can act as a promising delivery system for both taste masking and for enhancing the bioavailability of APZ.

Drug treatment developments in schizophrenia and bipolar mania: latest evidence and clinical usefulness

Schizophrenia and bipolar disorder are often highly debilitating with chronic courses, and psychotropic drugs represent cornerstones in the treatment. The primary aim of the review was to summarize the latest evidence with regards to the efficacy and effectiveness of drug treatment of schizophrenia and the manic phases of bipolar disorder. Schizophrenia systematic reviews conclude that antipsychotic drugs are effective in treating overall symptoms of psychosis and in preventing relapse. Some of the newer agents, the second-generation antipsychotics (SGAs), have demonstrated superiority compared with the older first-generation drugs and other SGAs but side-effect differences among the drugs are of a greater magnitude than effect differences. The pragmatic randomized trials of effectiveness have shown a longer time until treatment discontinuation for olanzapine compared with other antipsychotics. Cohort studies have found superiority for the long-acting injection formulations compared with the oral formulations of the drugs, and lower total mortality risk in users of antipsychotics compared with non-users. In bipolar mania SGAs have shown superior antimanic efficacy compared with other mood-stabilizing drugs. In conclusion antipsychotics, in particular some of the SGAs, seem to be drugs of first choice for both schizophrenia and bipolar mania. This perspective review focused on mean effects but the group means may not always be particularly useful as schizophrenia and bipolar mania are biologically heterogeneous disorders with large inter-individual variations in drug response and tolerance. In patients with a prior drug history the different pharmacological and clinical profiles may be exploited in subsequent choices of drugs.

Sucralose, a synthetic organochlorine sweetener: overview of biological issues

Sucralose is a synthetic organochlorine sweetener (OC) that is a common ingredient in the world's food supply. Sucralose interacts with chemosensors in the alimentary tract that play a role in sweet taste sensation and hormone secretion. In rats, sucralose ingestion was shown to increase the expression of the efflux transporter P-glycoprotein (P-gp) and two cytochrome P-450 (CYP) isozymes in the intestine. P-gp and CYP are key components of the presystemic detoxification system involved in first-pass drug metabolism. The effect of sucralose on first-pass drug metabolism in humans, however, has not yet been determined. In rats, sucralose alters the microbial composition in the gastrointestinal tract (GIT), with relatively greater reduction in beneficial bacteria. Although early studies asserted that sucralose passes through the GIT unchanged, subsequent analysis suggested that some of the ingested sweetener is metabolized in the GIT, as indicated by multiple peaks found in thin-layer radiochromatographic profiles of methanolic fecal extracts after oral sucralose administration. The identity and safety profile of these putative sucralose metabolites are not known at this time. Sucralose and one of its hydrolysis products were found to be mutagenic at elevated concentrations in several testing methods. Cooking with sucralose at high temperatures was reported to generate chloropropanols, a potentially toxic class of compounds. Both human and rodent studies demonstrated that sucralose may alter glucose, insulin, and glucagon-like peptide 1 (GLP-1) levels. Taken together, these findings indicate that sucralose is not a biologically inert compound.

Atypical antipsychotics in the treatment of depressive and psychotic symptoms in patients with chronic schizophrenia: a naturalistic study

Objectives. The aim of this naturalistic study was to investigate whether treatment with clozapine and other atypical antipsychotics for at least 2 years was associated with a reduction in psychotic and depressive symptoms and an improvement in chronic schizophrenia patients' awareness of their illness. Methods. Twenty-three adult outpatients (15 men and 8 women) treated with clozapine and 23 patients (16 men and 7 women) treated with other atypical antipsychotics were included in the study. Psychotic symptoms were evaluated using the Positive and Negative Syndrome Scale (PANSS), depressive symptoms were assessed with the Calgary Depression Scale for Schizophrenia (CDSS), and insight was assessed with the Scale to Assess Unawareness of Mental Disorder (SUMD). Results. The sample as a whole had a significant reduction in positive, negative, and general symptoms, whereas the reduction in depression was significant only for patients with CDSS scores of 5 and higher at the baseline. At the follow-up, patients treated with other atypical antipsychotics reported a greater reduction in depression than patients treated with clozapine, but not when limiting the analyses to those with clinically relevant depression. Conclusions. Atypical antipsychotics may be effective in reducing psychotic and depressive symptoms and in improving insight in patients with chronic schizophrenia, with no differences in the profiles of efficacy between compounds.

Cognitive effects of a single dose of atypical antipsychotics in healthy volunteers compared with placebo or haloperidol

Cognitive dysfunction in patients with schizophrenia is a strong correlate of poor outcome than any other symptom domain. To have greater knowledge about the effects of antipsychotics on cognitive function, subjects of this study were healthy volunteers who had no confounding variables typically found in patients with schizophrenia. The cognitive function of healthy volunteers in response to single doses of haloperidol, risperidone, aripiprazole, and amisulpride in a double-blind placebo-controlled trial was investigated. Assessments for the computerized neurocognitive test, mental and physical sedation, and extrapyramidal symptoms were performed within 1 week before (baseline) and approximately 4 hours after drug administration. Compared to the placebo, single administration of amisulpride at 400 mg in healthy volunteers enhanced word fluency test performance and remained intact after controlling for sedation and extrapyramidal symptoms. Significant improvement in some measurements of the computerized neurocognitive test was also observed in each antipsychotic-treated group but may have been related to practice effect. These findings suggest that amisulpride may have cognitive-enhancing effects in healthy volunteers.

Prominent clinical dimension, duration of illness and treatment response in schizophrenia: a naturalistic study

OBJECTIVE

Preliminary data indicate that predominant positive symptoms are predictive of subsequent treatment response, while negative and cognitive symptoms are associated with poor outcome. Purpose of the present study was to investigate the relation between the predominant clinical dimension, duration of illness and acute antipsychotic response in a sample of schizophrenic inpatients.

METHODS

Fifty-one schizophrenic inpatients, receiving an antipsychotic mono-therapy, were dimensionally assessed at the admission in the Acute Psychiatric Unit of the University of Milan. Treatment response was selected as parameter of outcome and defined as a reduction >50% of baseline total The Positive and Negative Syndrome Scale (PANSS) score. Demographic and clinical variables between responders and non-responders were compared using one-way analysis of variance for continuous variables and χ(2) test for dichotomous ones. Binary logistic regression was performed to find if dimensional scores and duration of illness were associated with acute antipsychotic response.

RESULTS

A longer duration of illness was found in non-responders respect to responders (15.61 years vs. 8.28 years)(F=4.98, p=0.03). Higher scores on PANSS positive sub-scale (OR=1.3, p=0.03), lower scores on cognitive PANSS scores (OR=0.75, p=0.05) and shorter duration of illness (OR=0.93, p=0.04) were found to be predictive of acute antipsychotic response.

CONCLUSION

These preliminary results show that a long duration of illness as well as a more severe cognitive impairment is predictive of treatment non-response, indicating a worse outcome for chronic patients with predominant cognitive symptoms.

New serotonin/dopamine antagonists for the treatment of schizophrenia: are we making real progress?

The introduction of second-generation antipsychotics (SGAs), heralded by clozapine in 1990, represented an important advance in the pharmacologic treatment of schizophrenia. However, several recent comparative effectiveness trials found that non-clozapine SGAs provided little or no advantage in efficacy over first-generation antipsychotics, and all agents had substantial safety and tolerability concerns. Clearly, there remains a great unmet need for more effective and better-tolerated antipsychotics. Relatively potent antagonism of serotonin 5-HT2A receptors coupled with relatively weaker antagonism of dopamine D2 receptors is the central pharmacological characteristic shared by most SGAs. This profile continues to be a favored model for developing new SGAs, commonly defined as serotonin/dopamine antagonists. In the past ten years, aripiprazole, paliperidone, asenapine, iloperidone, and lurasidone have been introduced. Studies suggest that the newer agents have similar short-term efficacy to earlier serotonin/dopamine antagonists, and several demonstrate at least modest improvements in safety and tolerability profiles, particularly metabolic measures. However, as a group, the newer serotonin/dopamine antagonists are pharmacologically heterogeneous, and their side-effect burden can still be considerable. Moreover, their putative clinical advantages have not yet been well demonstrated via direct comparative studies. The absence of such evidence adds to the challenges in defining their place among more established treatment choices, or in providing clinicians with clear indications to guide treatment choices for individual patients. Long-term, head-to-head comparative studies are required to clarify the risk/benefit profiles of the newer antipsychotics and their roles in the treatment of schizophrenia.