Advances in atypical antipsychotics for the treatment of schizophrenia: new formulations and new agents

Annulations of Ynamides with 1,2-Benzisothiazoles to Construct 1,4-Benzothiazepines and 3-Aminoisoquinolines

Two distinct TMSOTf-catalyzed annulation reactions between ynamides and 1,2-benzisothiazoles have been developed. The direction of the reaction could be easily switched by applying different thermodynamic-controlled conditions. At room temperature, ynamides undergo a [5 + 2] annulation reaction with 1,2-benzisothiazoles to afford 1,4-benzothiazepines, whereas under heating conditions a desulfurizative annulation reaction proceeds well to access 3-aminoisoquinolines. These two protocols provide biologically important 1,4-benzothiazepines and 3-aminoisoquinolines with high efficiency with broad substrate scopes under mild reaction conditions.

New Substituted 5-Benzylideno-2-Adamantylthiazol[3,2-b][1,2,4]Triazol-6(5H)ones as Possible Anti-Inflammatory Agents

Background: Inflammation is a complex response to noxious stimuli promoted by the release of chemical mediators from the damaged cells. Metabolic products of arachidonic acid, produced by the action of cyclooxygenase and lipoxygenase, play important roles in this process. Several non-steroidal anti-inflammatory drugs act as cyclooxygenase inhibitors. However, almost all of them have undesired side effects. Methods: Prediction of the anti-inflammatory action of the compounds was performed using PASS Program. The anti-inflammatory activity was evaluated by the carrageenan paw edema test. COX and LOX inhibitory actions were tested using ovine COX-1, human recombinant COX-2 and soybean LOX-1, respectively. Docking analysis was performed using Autodock. Results: All designed derivatives had good prediction results according to PASS and were synthesized and experimentally evaluated. The compounds exhibited in vivo anti-inflammatory action with eleven being equal or better than indomethacin. Although, some of them had no or low inhibitory effect on COX-1/2 or LOX, certain compounds exhibited COX-1 inhibition much higher than naproxen and COX-2 inhibition, well explained by Docking analysis. Conclusions: A number of compounds with good anti-inflammatory action were obtained. Although, some exhibited remarkable COX inhibitory action this activity did not follow the anti-inflammatory results, indicating the implication of other mechanisms.

Pharmacological Treatment of Schizophrenia: Japanese Expert Consensus

Introduction Conventional treatment guidelines of schizophrenia do not necessarily provide solutions on clinically important issues.

Methods A total of 141 certified psychiatrists of the Japanese Society of Clinical Neuropsychopharmacology evaluated treatment options regarding 19 clinically relevant situations in the treatment of schizophrenia with a 9-point scale (1=“disagree” and 9=“agree”).

Results First-line antipsychotics varied depending on predominant symptoms: risperidone (mean±standard deviation score, 7.9±1.4), olanzapine (7.5±1.6), and aripiprazole (6.9±1.9) were more likely selected for positive symptoms; aripiprazole (7.6±1.6) for negative symptoms; aripiprazole (7.3±1.9), olanzapine (7.2±1.9), and quetiapine (6.9±1.9) for depression and anxiety; and olanzapine (7.9±1.5) and risperidone (7.5±1.5) for excitement and aggression. While only aripiprazole was categorized as a first-line treatment for relapse prevention (7.6±1.0) in patients without noticeable symptoms, aripiprazole (8.0±1.6) and brexpiprazole (6.9±2.3) were categorized as such for social integration. First-line treatments in patients who are vulnerable to extrapyramidal symptoms include quetiapine (7.5±2.0) and aripiprazole (6.9±2.1).

Discussion These clinical recommendations represent the expert consensus on the use of a particular antipsychotic medication for a particular situation, filling a current gap in the literature.

Transdermal Delivery of Antipsychotics: Rationale and Current Status

The aim of this article is to provide the rationale for the development of transdermal formulations of antipsychotics by highlighting their main advantages, starting with an overview of the antipsychotic formulations that are currently available on the market. Progress regarding transdermal antipsychotic formulations was investigated by performing a search of papers, patents and clinical trials published in the last 10 years. Available data on antipsychotic transdermal formulations are reported and discussed, focusing on the characteristics of the dosage forms and their ability to promote drug absorption. Despite the current availability of a large number of antipsychotics, only a few of these drugs (e.g. aripiprazole, asenapine, blonanserin, chlorpromazine, haloperidol, olanzapine, prochlorperazine, quetiapine, and risperidone) have been developed as transdermal delivery systems. Several papers and patents show that transdermal formulations, such as creams, films, gels, nanosystems, patches, solutions, and sprays, have been evaluated with the aim of expanding the clinical utility of antipsychotic drugs. In particular, the employment of different strategies, such as the use of nanoparticles/vesicles, or permeation enhancers as well as microneedles with iontophoresis, may improve the absorption of antipsychotic drugs through the skin. However, few clinical trials on transdermal delivery of antipsychotic drugs are available and only delivery systems containing asenapine and blonanserin have shown interesting clinical results in terms of pharmacokinetic data, efficacy, and tolerability. Recently, the transdermal patch formulation of blonanserin was approved in Japan for the treatment of schizophrenia.

Olanzapine - Focus on the Cardiometabolic Side Effects

In this article, we review the recent findings concerning weight gain, diabetes mellitus (DM), hyperlipidemia, cardiovascular side effects in patients receiving olanzapine. It will consider the OLZ is associated with an increase in metabolic syndrome or cardiovascular events, and knowledge of these risks is crucial for further monitoring of patients with OLZ-treatment. Although it is one of the most commonly prescribed and effective AATPs, olanzapine causes the most weight gain and metabolic impairments in humans. As noted with glucose abnormalities and antipsychotics, olanzapine has the greatest propensity for causing proatherogenic hyperlipidemia. The mechanism of dyslipidemia with OLZ is poorly understood, but OLZ has been shown to increase lipogenesis, reduce lipolysis, and enhance the antilipolytic effects of insulin in adipocytes. Olanzapine can induce cardiomyopathy in selected patients.

Taken together, all mentioned data indicate that interventions aimed at the amelioration of obesity and cardiovascular illness need to be as multipronged and complex as the contributing psychosocial, behavioural, and biological factors that make obesity and cardiovascular illness more likely in patients with severe mental illness, including schizophrenia.

Oral nanomedicine approaches for the treatment of psychiatric illnesses

Psychiatric illnesses are a leading cause of disability and morbidity globally. However, the preferred orally dosed pharmacological treatment options available for depression, anxiety and schizophrenia are often limited by factors such as low drug aqueous solubility, food effects, high hepatic first-pass metabolism effects and short half-lives. Furthermore, the discovery and development of more effective psychotropic agents has stalled in recent times, with the majority of new drugs reaching the market offering similar efficacy, but suffering from the same oral delivery concerns. As such, the application of nanomedicine formulation approaches to currently available drugs is a viable option for optimizing oral drug delivery and maximizing treatment efficacy. This review focuses on the various delivery challenges encountered by psychotropic drugs, and the ability of nanomedicine formulation strategies to overcome these. Specifically, we critically review proof of concept in vitro and in vivo studies of nanoemulsions/microemulsions, solid lipid nanoparticles, dendrimers, polymeric micelles, nanoparticles of biodegradable polymers and nanosuspensions, and provide new insight into the various mechanisms for improved drug performance. The advantages and limitations of current oral nanomedicine approaches for psychotropic drugs are discussed, which will provide guidance for future research directions and assist in fostering the translation of such delivery systems to the clinical setting. Accordingly, emphasis has been placed on correlating the in vitro/in vivo performance of these nanomedicine approaches with their potential clinical outcomes and benefits for patients.

Impact of Sedation on Cognitive Function in Mechanically Ventilated Patients

The practice of sedation dosing strategy in mechanically ventilated patient has a profound effect on cognitive function. We conducted a comprehensive review of outcome of sedation on mental health function in critically ill patients on mechanical ventilation in the intensive care unit (ICU). We specifically evaluated current sedative dosing strategy and the development of delirium, post-traumatic stress disorders (PTSDs) and agitation. Based on this review, heavy dosing sedation strategy with benzodiazepines contributes to cognitive dysfunction. However, outcome for mental health dysfunction is mixed in regard to newer sedatives agents such as dexmedetomidine and propofol. Moreover, studies that examine the impact of sedatives for persistence of PTSD/delirium and its long-term cognitive and functional outcomes for post-ICU patients are frequently underpowered. Most studies suffer from low sample sizes and methodological variations. Therefore, larger randomized controlled trials are needed to properly assess the impact of sedation dosing strategy on cognitive function.

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.

Long-acting injectables and risk for rehospitalization among patients with schizophrenia in the home care program in Taiwan

We aimed at evaluating the relationship between medication and treatment effectiveness in a home care setting among patients with schizophrenia. Patients with schizophrenia hospitalized between 2004 and 2009 with a primary International Classification of Diseases, Ninth Revision, Clinical Modification code of 295 were identified from Psychiatric Inpatient Medical Claims Data released by the National Health Research Institute in Taiwan. Patients who joined the home care program after discharge and were prescribed long-acting injection (LAI) (the LAI group) or oral antipsychotic medications (the oral group) were included as study subjects. The final sample for the study included 810 participants in the LAI group and 945 in the oral group. Logistic regression was performed to examine the independent effect of LAI medication on the risk for rehospitalization within the 12-month observation window after controlling for patient and hospital characteristics and propensity score quintile adjustment. The unadjusted odds ratio for rehospitalization risk was 0.80 (confidence interval, 0.65-0.98) for the LAI group compared to the oral group. The adjusted odds ratio was further reduced to 0.78 (confidence interval, 0.63-0.97). Results remained unchanged when the propensity score quintiles were entered into the regression for further adjustment. In a home care setting, patients treated with long-acting antipsychotic agents are at a significantly lower risk for psychiatric rehospitalization than those treated with oral medication. Consequently, LAI home-based treatment for the prevention of schizophrenia relapse may lead to substantial clinical and economic benefits.

3D-QSAR study indicates an enhancing effect of membrane ions on psychiatric drugs targeting serotonin receptor 5-HT1A

Antidepressants and antipsychotics are psychiatric agents used for the treatment of various types of psychiatric diseases. Although currently among the most commonly prescribed drugs, their effectiveness and adverse effects are the topic of many studies and controversial claims. Here we generate QSAR models based on compounds series including 20 drugs recommended for two critical psychiatric diseases: depression and schizophrenia and we use these QSAR models to predict the biological activity of these 20 antidepressants and antipsychotics. We establish the membrane ions' contributions (sodium, potassium, calcium and iron) mediated by water to the antagonism of these drugs at the 5-HT1A receptor. The reliability of our QSAR models in predicting compounds activity is indicated by significant values for cross-validated correlation q² (0.60-0.76) and fitted correlation r² (0.96-0.98) coefficients. Our results indicate that potassium, calcium and iron play a key role for the antagonistic activity of drugs at the 5-HT1A receptor. Moreover, based on the established QSAR equations, we analysed 24 new escitalopram derivatives as possibly improved antidepressants targeting the 5-HT1A receptor. We identified that the presence of methyl groups and hydrogen atoms improves antidepressant activity while the simultaneous presence of ethyl, propyl or halogens decreased drastically antidepressant activity at the 5-HT1A site.

Searching the "biologically relevant"conformation of dopamine: a computational approach

We report here an exhaustive and complete conformational study on the conformational potential energy hypersurface (PEHS) of dopamine (DA) interacting with the dopamine D2 receptor (D2-DR). A reduced 3D model for the binding pocket of the human D2-DR was constructed on the basis of the theoretical model structure of bacteriorhodopsin. In our reduced model system, only 13 amino acids were included to perform the quantum mechanics calculations. To obtain the different complexes of DA/D2-DR, we combined semiempirical (PM6), DFT (B3LYP/6-31G(d)), and QTAIM calculations. The molecular flexibility of DA interacting with the D2-DR was evaluated from potential energy surfaces and potential energy curves. A comparative study between the molecular flexibility of DA in the gas phase and at D2-DR was carried out. In addition, several molecular dynamics simulations were carried out to evaluate the molecular flexibility of the different complexes obtained. Our results allow us to postulate the complexes of type A as the "biologically relevant conformations" of DA. In addition, the theoretical calculations reported here suggested that a mechanistic stepwise process takes place for DA in which the protonated nitrogen group (in any conformation) acts as the anchoring portion, and this process is followed by a rapid rearrangement of the conformation allowing the interaction of the catecholic OH groups.

Iloperidone: A new drug for the treatment of schizophrenia

PURPOSE

The pharmacology, pharmacokinetics, pharmacogenomics, clinical efficacy, and safety and tolerability profile of iloperidone for the treatment of schizophrenia are reviewed.

SUMMARY

Iloperidone is an atypical antipsychotic that recently received marketing approval from the Food and Drug Administration for the acute treatment of schizophrenia. Iloperidone is a pure antagonist and the first antipsychotic to have pharmacogenomic studies indicate predictive response based on six identified polymorphisms. Pharmacokinetic studies have determined that iloperidone is well absorbed orally, with a bioavailability of 96%. Phase II and III clinical trials have shown iloperidone to improve symptoms of schizophrenia, based on the Positive and Negative Symptom Scale, Brief Psychiatric Rating Scale, and Clinical Global Impressions-Severity scores (p < 0.05). Iloperidone has established tolerability at recommended dosages of up to 24 mg daily; however, the dosage must be slowly increased over seven days, and twice-daily administration is required to avoid orthostatic hypotension. The most common adverse effects associated with iloperidone were dizziness, dry mouth, fatigue, nasal congestion, orthostatic hypotension, somnolence, tachycardia, and weight gain. Safety studies have also found that iloperidone increases the risk of Q-Tc interval prolongation, similar to that seen with ziprasidone. Minimal changes in glucose and lipid abnormalities were seen in short-term (4- and 6-week) and long-term (52-week) studies, indicating a low chance of metabolic disturbance with iloperidone.

CONCLUSION

Iloperidone may be a viable and safe option for the treatment of schizophrenia in adult patients, especially for patients who cannot tolerate other antipsychotic agents. However, iloperidone lacks a clear benefit over other antipsychotic agents.

QSAR-CoMSIA applied to antipsychotic drugs with their dopamine D2 and serotonine 5HT2A membrane receptors

Antipsychotic drugs are psychiatric medication primarily used to manage psychosis (e.g., delusions or hallucinations), particularly in schizophrenia and bipolar disorder. First and second generations of antipshychotics tend to block receptors in the brain's dopamine pathways, but antipsychotic drugs encompass a wide range of receptor targets. The inhibition constant, Ki, at the level of membrane receptors is a major determinant of their pharmacokinetic behavior and, consequently, it can affect their antipsychotic activity. Here, predicted inhibition constants, Ki for 71 antipsychotics, already approved for clinical treatment, as well as representative new chemical structures which exhibit antipsychotic activity, were evaluated using 3D-QSAR-CoMSIA models. Significant values of the cross-validated correlation q2 (higher than 0.70) and the fitted correlation r2 (higher than 0.80) revealed that these models have reasonable power to predict the biological affinity of the 15 new risperidone and 12 new olanzapine derivatives in interactions with dopamine D2 and serotonin 5HT2A receptors; these compounds are suggested for further studies.

CNS disorders--current treatment options and the prospects for advanced therapies

The development of new pharmaceutical products has successfully addressed a multitude of disease states; however, new product development for treating disorders of the central nervous system (CNS) has lagged behind other therapeutic areas. This is due to several factors including the complexity of the diseases and the lack of technologies for delivery through the blood-brain barrier (BBB). This article examines the current state of six major CNS disease states: depression, epilepsy, multiple sclerosis (MS), neurodegenerative diseases (specifically Alzheimer's disease [AD]), neuropathic pain, and schizophrenia. Discussion topics include analysis of the biological mechanisms underlying each disease, currently approved products, and available animal models for development of new therapeutic agents. Analysis of currently approved therapies shows that all products depend on the molecular properties of the drug or prodrug to penetrate the BBB. Novel technologies, capable of enhancing BBB permeation, are also discussed relative to improving CNS therapies for these disease states.

Metformin for metabolic dysregulation in schizophrenic patients treated with olanzapine

The second generation antipsychotic drugs, such as risperidone, olanzapine, and quetiapine, are effective in treating patients with schizophrenia and have been considered as the first line therapy. Recently, increasing attention has been drawn to the potential diabetogenic effect of these novel antipsychotics. The goal of this study was to evaluate the effect of metformin treatment on the olanzapine-induced metabolic disturbance in schizophrenic patients. Twenty-four schizophrenic subjects who had received olanzapine treatment at least 3 months were assigned to the therapy with metformin 1500 mg/day for 8 weeks. The metabolic parameters were quantitatively assessed at baseline, weeks 2, 4, and 8 by using the intravenous glucose tolerance test. After an 8-week treatment with metformin, the body weight, fasting levels of glucose, triglyceride, and insulin, insulin secretion, and insulin resistance significantly decreased. Half of study subjects with metabolic syndrome obtained improvement after the metformin trial. Subjects' psychopathological condition remained unchanged during the study period. The olanzapine-induced metabolic disturbance could be reversed after 8-week metformin treatment. Based on the results of this study, we hypothesize that metformin could modulate the effect of olanzapine-induced metabolic disturbance.

Do formulation switches exacerbate existing medical illness? Results of an open-label transition to orally disintegrating risperidone tablets

BACKGROUND

Orally disintegrating risperidone tablets (Risperdal* M-TABs*) present an alternative method of drug delivery that may benefit physicians struggling to treat non-compliant patients, since it begins to dissolve within 5 s, preventing tablet cheeking or spitting.

OBJECTIVES

To evaluate safety and maintenance of effect in symptomatically stable patients transitioned from compressed risperidone tablets to orally disintegrating risperidone tablets.

METHODS

This open-label, multi-centre study enrolled 82 adults from four diagnostic groups (major depressive disorder (MDD), n = 25; bipolar disorder (BP), n = 21; dementia (DE), n = 20; schizophrenia (SZ), n = 16). Patients were switched from their previous dosage of compressed tablets (0.5, 1.0, 2.0, 3.0, or 4.0 mg/day) to an equivalent dosage of orally disintegrating risperidone and followed for 4 weeks. The primary effectiveness parameter evaluated was the Clinical Global Impression-Severity (CGI-S) scale.

RESULTS

Most patients (24/25 MDD; 20/21 BP; 17/18 DE; 14/15 SZ) improved by 1 point on CGI-S from baseline or experienced no change at endpoint. Adverse events (AEs) occurring in any group at a > or =10% incidence included headache (19%) and pharyngolaryngeal pain (10%), reported in the BP group only.

CONCLUSIONS

Patients stabilized on compressed risperidone tablets transitioned to the equivalent dose of orally disintegrating risperidone tablets with continued maintenance of effect, no decompensation and with minimal side effects.

Brain neurotransmitter receptor-binding characteristics in rats after oral administration of haloperidol, risperidone and olanzapine

The present study was conducted to characterize the binding of neurotransmitter receptors (dopamine D(2), serotonin 5-HT(2), histamine H(1), adrenaline alpha(1) and muscarine M(l) receptors) in the rat's brain after the oral administration of haloperidol, risperidone, and olanzapine. Haloperidol at 1 and 3 mg/kg displayed significant activity to bind the D(2) receptor (increase in the Kd value for [(3)H]raclopride binding) in the corpus striatum with little change in the activity toward the 5-HT(2) receptor (binding parameters for [(3)H]ketanserin). In contrast, risperidone (0.1-3 mg/kg) showed roughly 30 times more affinity for the 5-HT(2) receptor than D(2) receptor. Also, olanzapine (1-10 mg/kg) was most active toward the H(1) receptor in the cerebral cortex, corpus striatum, and hippocampus, was less active in binding 5-HT(2) and D(2) receptors, and showed the least affinity for alpha(1) and M(1) receptors. In conclusion, haloperidol and risperidone administered orally selectively bind D(2) and 5-HT(2) receptors, respectively, in the rat brain, while olanzapine binds H(1), 5-HT(2), and D(2) receptors more than alpha(1) and M(1) receptors.

Design and synthesis of novel derivatives of the muscarinic agonist tetra(ethylene glycol)(3-methoxy-1,2,5-thiadiazol-4-yl) [3-(1-methyl-1,2,5,6-tetrahydropyrid-3-yl)-1,2,5-thiadiazol-4-yl] ether (CDD-0304): effects of structural modifications on the binding and activity at muscarinic receptor subtypes and chimeras

As part of a continuing effort to design and synthesize highly selective muscarinic agonists for different muscarinic receptor subtypes, several tetra(ethylene glycol)(3-methoxy-1,2,5-thiadiazol-4-yl) [3-(1-methyl-1,2,5,6-tetrahydropyrid-3-yl)-1,2,5-thiadiazol-4-yl] ether (1) analogues were prepared and characterized. Different analogues were synthesized having hydrophilic spacers of di-, tri-, tetra-, penta(ethylene glycol) and tri(propylene glycol) separating the 1,2,5,6-tetrahydropyridine ring from the terminal heterocycle, which was either a 1,2,5-thiadiazole or 1,2,4-thiadiazole ring. Chimeric receptor and molecular modeling studies also were conducted to determine how the ligands interact with muscarinic receptors. The studies revealed that varying the distance of the terminal thiadiazole and the positioning of the methoxy group can increase binding affinity for certain muscarinic receptor subtypes (at M(2) for 13d and M(4) for 1) and enhance functional efficacy at M(4) receptors for 13e and 18b. Moreover, compound 1 exhibited antipsychotic activity as assessed by reversal of apomorphine-induced sensory motor gating deficits, suggesting potential utility in the treatment of schizophrenia.

Clinical Pharmacokinetics of Atypical Antipsychotics

In the past, the information about the dose-clinical effectiveness of typical antipsychotics was not complete and this led to the risk of extrapyramidal adverse effects. This, together with the intention of improving patients' quality of life and therapeutic compliance, resulted in the development of atypical or second-generation antipsychotics (SGAs). This review will concentrate on the pharmacokinetics and metabolism of clozapine, risperidone, olanzapine, quetiapine, amisulpride, ziprasidone, aripiprazole and sertindole, and will discuss the main aspects of their pharmacodynamics. In psychopharmacology, therapeutic drug monitoring studies have generally concentrated on controlling compliance and avoiding adverse effects by keeping long-term exposure to the minimal effective blood concentration. The rationale for using therapeutic drug monitoring in relation to SGAs is still a matter of debate, but there is growing evidence that it can improve efficacy, especially when patients do not respond to therapeutic doses or when they develop adverse effects. Here, we review the literature concerning the relationships between plasma concentrations of SGAs and clinical responses by dividing the studies on the basis of the length of their observation periods. Studies with clozapine evidenced a positive relationship between plasma concentrations and clinical response, with a threshold of 350-420 ng/mL associated with good clinical response. The usefulness of therapeutic drug monitoring is well established because high plasma concentrations of clozapine can increase the risk of epileptic seizures. Plasma clozapine concentrations seem to be influenced by many factors such as altered cytochrome P450 1A4 activity, age, sex and smoking. The pharmacological effects of risperidone depend on the sum of the plasma concentrations of risperidone and its 9-hydroxyrisperidone metabolite, so monitoring the plasma concentrations of the parent compound alone can lead to erroneous interpretations. Despite a large variability in plasma drug concentrations, the lack of studies using fixed dosages, and discrepancies in the results, it seems that monitoring the plasma concentrations of the active moiety may be useful. However, no therapeutic plasma concentration range for risperidone has yet been clearly established. A plasma threshold concentration for parkinsonian side effects has been found to be 74 ng/mL. Moreover, therapeutic drug monitoring may be particularly useful in the switch between the oral and the long-acting injectable form. The reviewed studies on olanzapine strongly indicate a relationship between clinical outcomes and plasma concentrations. Olanzapine therapeutic drug monitoring can be considered very useful in assessing therapeutic efficacy and controlling adverse events. A therapeutic range of 20-50 ng/mL has been found. There is little evidence in favour of the existence of a relationship between plasma quetiapine concentrations and clinical responses, and an optimal therapeutic range has not been identified. Positron emission tomography studies of receptor blockade indicated a discrepancy between the time course of receptor occupancy and plasma quetiapine concentrations. The value of quetiapine plasma concentration monitoring in clinical practice is still controversial. Preliminary data suggested that a therapeutic plasma amisulpride concentration of 367 ng/mL was associated with clinical improvement. A therapeutic range of 100-400 ng/mL is proposed from non-systematic clinical experience. There is no direct evidence concerning optimal plasma concentration ranges of ziprasidone, aripiprazole or sertindole.

Advances in psychotropic formulations

BACKGROUND

Successful pharmacotherapy is dependent on several factors. While efficacy is obviously important, other factors that are often overlooked include the availability of optimal dosage forms, treatment compliance and reduction in side effects. A number of innovative delivery systems have been developed to address suboptimal therapy outcomes by enhancing drug delivery, assuring efficacy of treatment, reducing side effects, and improving compliance.

OBJECTIVE

The purpose of this review is to discuss the advances in formulations for various psychotropic agents that have been developed for the treatment of psychiatric illnesses such as depression, attention deficit hyperactivity disorder, schizophrenia and other psychotic disorders.

METHODS

Information was identified via a MEDLINE and EMBASE search of data published between 2002 and 2005 with keywords 'psychotropic', 'atypical antipsychotic', 'antidepressant' or 'anxiolytic' in combination with 'new/novel/advanced formulation/delivery/technology', or 'controlled release/extended release', or 'fast-acting/fast-dissolving/orodispensible', or 'intramuscular/inject'.

RESULTS

In antidepressant therapy, formulations that allow extended release for once-daily and even once-weekly administration, orally disintegrating tablets, and transdermal systems have all been introduced. Long-acting central nervous system stimulants for the treatment of attention deficit hyperactivity disorder eliminate the need for multiple dosing. A number of new formulations of atypical antipsychotic agents have become available, offering important alternatives in certain patient groups. These include rapid-acting intramuscular injections, liquid formulations, and fast-dissolving tablets, all of which are useful options in the acute treatment setting as well as for geriatric and/or pediatric populations. Furthermore, formulations that deliver sustained levels of medications, including a long-acting antipsychotic and a new extended-release oral formulation, are important new developments that may improve compliance and offer efficacy and safety benefits in long-term management.

CONCLUSIONS

New formulations of psychotropics can offer advantages over older formulations in terms of convenience, side-effect profiles, efficacy, and/or a fast onset of action. Treatment-related factors can help to enhance patient's satisfaction with treatment and compliance, thereby improving patient prognosis and outcomes in both acute and outpatient management.

Solid state characterization of olanzapine polymorphs using vibrational spectroscopy

FT-Raman, infrared and near infrared investigations of two polymorphs of olanzapine are presented, establishing the main features that allow the discrimination of these crystalline forms using vibrational spectroscopic methods. Ab initio calculations on the basis of the density functional theory were used to determine the stable conformations. The calculated vibrational spectra were compared to the experimental ones in order to identify the conformers corresponding to each polymorph and to assign the vibrational bands to the internal vibrations of the olanzapine molecule. Our results support the hydrogen bonding pattern proposed by the reported crystalline structure and provide valuable information on the structural and thermodynamical relationship between the investigated polymorphs.

Iloperidone reduces sensorimotor gating deficits in pharmacological models, but not a developmental model, of disrupted prepulse inhibition in rats

Iloperidone is a novel atypical antipsychotic which acts as a broad spectrum dopamine/serotonin/norepinephrine receptor antagonist. To compare iloperidone behaviorally to other known antipsychotics, we evaluated the drug in three pharmacological models and one developmental model of disrupted prepulse inhibition (PPI) in rats. Firstly, 0.5 mg/kg apomorphine induced PPI deficits that were prevented by pretreatment with iloperidone (1 and 3 mg/kg). Secondly, treatment with the N-methyl-D-aspartate (NMDA)-receptor antagonist phencyclidine (PCP) produced robust deficits in PPI. Both doses of iloperidone (1 and 3 mg/kg) prevented the PPI-disruptive effects of treatment with 1 mg/kg PCP. Thirdly, treatment with the alpha1-adrenoceptor agonist cirazoline (0.6 mg/kg) disrupted PPI, and produced a concurrent large increase in startle magnitude. A relatively low dose of iloperidone (0.3 mg/kg) prevented cirazoline-induced PPI deficits, independent of its effects on startle magnitude. Finally, iloperidone (1 mg/kg) did not reverse PPI deficits in the isolation-rearing model of schizophrenia. These results indicate that iloperidone exerts behavioral effects in pharmacological models of disrupted sensorimotor gating consistent with "atypical" antipsychotics, mediated by antagonism of dopaminergic and noradrenergic receptors. The absence of effect in isolation-reared rats may be due to the relatively small effect size of isolation rearing on PPI or dose of iloperidone.

Pharmacotherapy of delusional disorders in the context of offending and the potential for compulsory treatment

Delusional disorder is an uncommon mental illness with an estimated prevalence of 0.03%. Its low prevalence has likely contributed to the paucity of research interest in this area, leading to substantial gaps in knowledge concerning its treatment and management. In the absence of a robust literature, most clinicians rely on their experience and guidelines for treating schizophrenia when treating patients with delusional disorder. This article reviews the available literature that is specific to the treatment of delusional disorder. In addition, it focuses on specific forensic and medicolegal aspects of managing patients with delusional disorder.

Emergency management of agitation in schizophrenia

Schizophrenia is a common psychiatric condition, affecting approximately 1% of the population. Acute emergent presentations often include hallucinations, delusions, thought, and speech disorders. Agitation is common among emergency patients with schizophrenia. Decisional capacity should be assessed in all patients. Reversible causes of agitation should be ruled out, including infection, metabolic disorders, endocrine disorders, trauma, pain, noncompliance, toxicological disorders, and structural brain abnormalities. Agitation may be managed acutely using a combination of pharmacological agents and nonpharmacological interventions. Effective pharmacological agents include several classes of antipsychotic agents and benzodiazepines. Potential life-threatening complications of pharmacological therapy should be anticipated, which may include neuroleptic malignant syndrome (NMS), prolonged QT syndrome, and respiratory depression. Nonpharmacological interventions may include a quiet environment, physical restraints, and behavioral interventions. Disposition decisions should be made based on the etiology of agitation, effective management, decisional capacity, and presence of suicidal or homicidal intentions. Many patients who have required nonpharmacological or pharmacological management of agitation require inpatient psychiatric treatment, either voluntarily or involuntarily. Psychiatric consultation should be sought for patients with schizophrenia and uncertain disposition determinations, or those requiring other complex management decisions.

Pharmacoeconomic evaluation of schizophrenia in Taiwan: model comparison of long-acting risperidone versus olanzapine versus depot haloperidol based on estimated costs

Antipsychotics are the keystone in schizophrenia treatment. Although the benefits of the new generation of antipsychotics has been demonstrated over the last decade, the issues of patient compliance and higher purchasing price of atypical antipsychotics remain unresolved. Risperidone is the only atypical antipsychotic agent with long-acting formulation. Long-acting risperidone is a water-based injection and it has been associated with a low level of pain. The aim of the present study was to test whether an improvement in compliance with the use of a long-acting risperidone, compared with olanzapine and depot haloperidol, can increase the effectiveness and the cost-effectiveness indexes. An economic comparison model with decision tree, rather than a prospective design with real clinical drug trial, was applied. The unit cost for each medical procedure was obtained from the claimed-database of the Bureau of National Health Insurance in Taiwan. An executive committee simulated the incidence of extrapyramidal side-effects and proposed a therapeutic model for each strategy based on a literature review. The probabilities of treatment response of different agents and those of different mental health states were estimated by the executive committee and 10 senior psychiatrists who were randomly selected. Sensitivity analysis was performed for drug cost-effectiveness and compliance improvement for using long-acting risperidone. The results showed that long-acting risperidone is more cost-effective than either olanzapine or depot haloperidol for treating schizophrenia patients whose conditions are stable and whose illness duration ranges from 1 to 5 years. The comparison model with the Kaplan-Meier decision tree may serve as an alternative to prospectively designed studies for cost-effectiveness of atypical antipsychotics.

Clinical review of a long-acting, injectable formulation of risperidone

BACKGROUND

A long-acting, injectable risperidone formulation is the first depot atypical antipsychotic drug to become available in the United States.

OBJECTIVE

The intent of this article is to review the efficacy and safety data available for long-acting, injectable risperidone.

METHODS

Information was identified via MEDLINE (years, 1990-May 2004) using the terms risperidone, long-acting injectable, depot, and delayed-action preparations. The manufacturer also provided information about risperidone in the form of abstracts and summaries of professional meetings.

RESULTS

Several 12-week studies and one 12-month study suggest that long-acting risperidone is an effective and well-tolerated treatment option for the maintenance therapy of schizophrenia. Thus far, no unexpected adverse events have been reported with the long-acting formulation. Extrapyramidal symptoms with long-acting risperidone were uncommon, dose-related, and similar to those observed with oral risperidone in short-term trials. A small, dose related weight gain occurred with long acting risperidone, again similar to that seen with oral risperidone. Pain at the injection site was uncommon and decreased with continued administration. The long-acting, injectable formulation comes in an aqueous suspension of microspheres. There is no initial drug release after injection; the main release of risperidone begins at week 2 to 3 postinjection, increases during weeks 3 and 4, is maintained during weeks 4 through 6, and declines between weeks 6 and 7. With repeated injections every 2 weeks, steady-state levels are usually reached by weeks 6 to 8. For most patients, the initial dosage should be 25 mg every 2 weeks, and oral administration should continue for the first 3 weeks after initial injection. Doses can be increased every 8 weeks to a maximum of 50 mg every 2 weeks.

CONCLUSION

Long-acting risperidone offers clinicians a combination of the benefits of a depot antipsychotic drug with the therapeutic advantages of an atypical antipsychotic drug.

Acceptability and disintegration rates of orally disintegrating risperidone tablets in patients with schizophrenia or schizoaffective disorder

OBJECTIVE

To investigate the disintegration profile, acceptability, and tolerability of orally disintegrating risperidone tablets in patients with schizophrenia or schizoaffective disorder.

METHOD

Ten patients stable for at least 10 days on monotherapy with oral risperidone 2 mg to 4 mg taken once daily were switched for 7 days to an equivalent dosage of orally disintegrating risperidone. Visual assessments for time to initial and complete disintegration were collected at each visit. Clinical Global Impression of Severity scores were collected at baseline and at the last visit. Patient acceptance of the new formulation, rated according to a visual analog scale, was obtained at the last visit.

RESULTS

All patients maintained stable clinical status. Mean time to initial disintegration was 5.1 seconds, SD 0.8, and mean time to complete disintegration was 29.4 seconds, SD 18.4. The formulation was rated as very acceptable. Adverse events were reported by 5 patients; all were mild.

CONCLUSION

The orally disintegrating risperidone tablets were well tolerated and rated as very acceptable by all patients.

Dose response and atypical antipsychotics in schizophrenia

Based on information from clinical trials, both the efficacy and adverse effects of conventional antipsychotics in the treatment of schizophrenia are dose related. The overlapping nature of these dose-response profiles limits the use of these agents. Atypical antipsychotics provide greater relief across the comorbid symptom domains of schizophrenia, but dose-response studies and clinical experience have revealed that some of these drugs also have dose limitations. This article reviews the dose-response relationships of the atypical antipsychotics as presented predominantly in pivotal, randomised studies (double-blind and otherwise). Limited data indicate that clozapine shows dose-related efficacy up to 600 mg/day in patients with treatment-resistant schizophrenia. However, higher dosages of clozapine may be associated with the risk of seizures. Risperidone demonstrates dose-related adverse events that compromise efficacy. The dose-response relationships for ziprasidone, quetiapine and aripiprazole are less well established. The efficacy of olanzapine appears to be dose related within the recommended dosage range of 10-20 mg/day, but clinical trials that have explored higher dosages suggest improved efficacy. Furthermore, the higher doses are not associated with a significantly increased incidence of adverse events. Further studies are clearly needed to fully characterise the dose-response relationships of atypical antipsychotics.

Novel Atypical Antipsychotic Agents: Rational Design, an Efficient Palladium-Catalyzed Route, and Pharmacological Studies

Using rational drug design to develop atypical antipsychotic drug candidates, we generated novel and metabolically stable pyrrolobenzazepines with an optimized pK(i) 5-HT(2A)/D(2) ratio. 5a, obtained by a new palladium-catalyzed three-step synthesis, was selected for further pharmacological and biochemical investigations and showed atypical antipsychotic properties in vivo. 5a was active on conditioned avoidance response at 0.56 mg/kg, it had low cataleptic potential and proved to be better than ST1899, clozapine, and olanzapine, representing a new clinical candidate.

Ethical use of long-acting medications in the treatment of severe and persistent mental illnesses

volunteerism Mental illnesses are prevalent, cause great suffering, and are burdensome to society. Traditional "depot" antipsychotic agents are used to treat the most severely and persistently mentally ill individuals. They will soon be joined by new atypical antipsychotic medications in long-acting formulations. These long-acting medications pose special ethical issues, but may greatly benefit some people who suffer from severe and persistent mental illnesses. The objective of the current report is to highlight ethical considerations related to the use of long-acting antipsychotic medications. An analysis centering on the ethical concepts of voluntarism, beneficence, and justice is performed, integrating relevant empirical evidence and bioethics principles. Two main conceptual issues related to constraints upon voluntarism and coercion exist. Careful examination of ethically important empirical evidence suggests that voluntarism may not be perceived as an issue for some persons receiving depot antipsychotic medications. A favorable balance of benefits and risks has been documented for some individuals with severe and persistent mental illnesses. Access to care, innovative treatments, and long-acting antipsychotic medications may arise as an issue of justice and nondiscrimination in the care of mental illness. Considerations of justice indicate that long-acting medications may need to be used more frequently and earlier in the course of severe and persistent mental illness for select patients. We conclude that great care should be given to ethically important issues surrounding voluntarism, beneficent care, and equitable access to innovative psychiatric treatments, especially for persons who carry the burden of stigma as well as severe and persistent mental illness.

Quetiapine. A review of its use in the management of schizophrenia

Quetiapine (Seroquel), a dibenzothiazepine derivative, is an atypical antipsychotic with demonstrated efficacy in acute schizophrenia. In short-term, randomised, double-blind trials, it was usually more effective than placebo, and was generally effective against both positive and negative symptoms. Overall, quetiapine (up to 750 mg/day) was at least as effective as chlorpromazine (up to 750 mg/day) and had similar efficacy to haloperidol (up to 16 mg/day) in patients with acute schizophrenia in randomised, double-blind trials; it was at least as effective as haloperidol 20 mg/day in patients with schizophrenia unresponsive or partially responsive to previous antipsychotic treatment. Improvements in overall psychopathology and positive and negative symptoms with quetiapine (up to 800 mg/day) were similar to those with risperidone (up to 8 mg/day) or olanzapine (15 mg/day) [interim analysis]. Efficacy was maintained for at least 52 weeks in open-label follow-up studies in adult and elderly patients. Quetiapine improved cognitive function versus haloperidol, and depressive symptoms and hostility/aggression versus placebo. Quetiapine is well tolerated. It is associated with placebo-level incidence of extrapyramidal symptoms (EPS) across its entire dose range, appears to have a low risk for EPS in vulnerable patient groups (e.g. the elderly, adolescents or patients with organic brain disorders) and has a more favourable EPS profile than risperidone. Irrespective of dose, quetiapine, unlike risperidone and amisulpride, does not elevate plasma prolactin levels compared with placebo, and previously elevated levels may even normalise. Quetiapine appears to have minimal short-term effects on bodyweight and a favourable long-term bodyweight profile. Preliminary studies indicate that there is a high level of patient acceptability and satisfaction with quetiapine. In conclusion, quetiapine has shown efficacy against both positive and negative symptoms of schizophrenia, and has benefits in improving cognitive deficits, affective symptoms and aggression/hostility. The beneficial effects of quetiapine have been maintained for at least 52 weeks. Quetiapine was effective and well tolerated in hard-to-treat patients, and may be of particular use in these individuals. It is at least as effective as standard antipsychotics and appears to have similar efficacy to risperidone and olanzapine. The relative risk/benefit profile of quetiapine compared with other atypical antipsychotics requires further research in head-to-head trials, although quetiapine's relatively benign tolerability profile distinguishes it from other commonly used atypical agents, particularly with respect to bodyweight, EPS and plasma prolactin levels. Overall, quetiapine has an excellent risk/benefit profile and is a suitable first-line option for the treatment of schizophrenia.

A review of compliance, depot intramuscular antipsychotics and the new long-acting injectable atypical antipsychotic risperidone in schizophrenia

BACKGROUND

Several oral atypical antipsychotics are available for schizophrenia management. Besides positive and negative symptom control, they may improve cognition. Due to their limited availability as oral agents only, benefits are limited by noncompliance.

METHODS

Using Medline and PsycINFO databases, literature was reviewed to address: (1) factors underlying medication noncompliance; (2) available evidence on efficacy of depot intramuscular (IM) typical antipsychotics; and (3) current knowledge of long-acting atypicals.

RESULTS

Noncompliance remains high due to illness-, treatment-, and clinician-related factors. Compared to oral typicals, atypicals may improve compliance, even though noncompliance remains high. Depot IM typicals are efficacious (reduced relapses and rehospitalizations), but extrapyramidal symptoms are problematic. Available data on long-acting atypical risperidone suggest that it is safe and efficacious.

CONCLUSION

Development of long-acting injectable atypical agents is warranted since noncompliance remains high. Future long-acting IM atypical trials should include outpatient functioning, and preferably be of longer duration to address cost-effectiveness.

Pyrrolo[1,3]benzothiazepine-Based Serotonin and Dopamine Receptor Antagonists. Molecular Modeling, Further Structure−Activity Relationship Studies, and Identification of Novel Atypical Antipsychotic Agents

Recently we reported the pharmacological characterization of the 9,10-dihydropyrrolo[1,3]benzothiazepine derivative (S)-(+)-8 as a novel atypical antipsychotic agent. This compound had an optimum pK(i) 5-HT(2A)/D(2) ratio of 1.21 (pK(i) 5-HT(2A) = 8.83; pK(i) D(2) = 7.79). The lower D(2) receptor affinity of (S)-(+)-8 compared to its enantiomer was explained by the difficulty in reaching the conformation required to optimally fulfill the D(2) pharmacophore. With the aim of finding novel atypical antipsychotics we further investigated the core structure of (S)-(+)-8, synthesizing analogues with specific substituents; the structure-activity relationship (SAR) study was also expanded with the design and synthesis of other analogues characterized by a pyrrolo[2,1-b][1,3]benzothiazepine skeleton, substituted on the benzo-fused ring or on the pyrrole system. On the 9,10-dihydro analogues the substituents introduced on the pyrrole ring were detrimental to affinity for dopamine and for 5-HT(2A) receptors, but the introduction of a double bond at C-9/10 on the structure of (S)-(+)-8 led to a potent D(2)/5-HT(2A) receptor ligand with a typical binding profile (9f, pK(i) 5-HT(2A)/D(2) ratio of 1.01, log Y = 8.43). Then, to reduce D(2) receptor affinity and restore atypicality on unsaturated analogues, we exploited the effect of specific substitutions on the tricyclic system of 9f. Through a molecular modeling approach we generated a novel series of potential atypical antipsychotic agents, with optimized 5HT(2A)/D(2) receptor affinity ratios and that were easier to synthesize and purify than the reference compound (S)-(+)-8. A number of SAR trends were identified, and among the analogues synthesized and tested in binding assays, 9d and 9m were identified as the most interesting, giving atypical log Y scores respectively 4.98 and 3.18 (pK(i) 5-HT(2A)/D(2) ratios of 1.20 and 1.30, respectively). They had a multireceptor affinity profile and could be promising atypical agents. Compound 9d, whose synthesis is easier and whose binding profile is atypical (log Y score similar to that of olanzapine, 3.89), was selected for further biological investigation. Pharmacological and biochemical studies confirmed an atypical antipsychotic profile in vivo. The compound was active on conditioned avoidance response at 1.1 mg/kg, a dose 100-times lower than that required to cause catalepsy (ED(50) >90 mg/kg), it induced a negligible increase of prolactin serum levels after single and multiple doses, and antagonized the cognitive impairment induced by phencyclidine. In conclusion, the pharmacological profile of 9d proved better than clozapine and olanzapine, making this compound a potential clinical candidate.

Pharmacotherapy of first-episode psychosis

Early intervention in psychosis has attracted more attention in the last few years. The treatment of this phase of the disorders requires a specific and adapted approach. The issue of engaging the patient is so critical that it influences not only the choice of medication, but also the context and the way in which it is administered. In the case of a first admission, patients should be observed for 24-48 h without any antipsychotic treatment, in order to clarify the diagnosis and exclude the possibility that symptoms are caused by acute intoxication with illicit substances, for example. The diagnosis is often difficult and unstable. A dimensional, rather than a categorical approach, is usually more likely to be adopted. In recent years, atypical antipsychotics have become the most frequently used first-line treatment. They are less likely to cause secondary negative symptoms, cognitive impairments and dysphoria. They also appear to influence the course of depression and hostility/aggression better than conventional neuroleptics, have possibly mood-stabilising properties and, subjectively, are often better accepted by patients. On the risk side, prevalence of acute extrapyramidal side effects and possibly tardive dyskinesia are lower, compared to the older neuroleptics. Although, the risk for short-term weight gain, cardiovascular, and especially hyperglycaemic complications are somewhat higher for some of these antipsychotics. Finally, the dose should be adapted as it has been shown that patients presenting a first psychotic episode respond to a lower dose of antipsychotic. This article focuses on the pharmacotherapy of first-episode psychosis, on the basis of a computerised and a manual search for articles dealing with antipsychotic treatment of these patients. Findings are discussed and combined in clinical guidelines for first-episode affective and non-affective psychosis, for patients with incomplete recovery or treatment resistance, for cases of emergency and for side effects associated with antipsychotic treatment.

Identification and management of delirium in the critically ill patient with cancer

Rather than a specific entity, delirium is at the midpoint on a spectrum of potential mental status changes that ranges from full consciousness to deep coma. The extremes are relatively easy to recognize, but other points along the spectrum may go unrecognized or be misdiagnosed. If recognized and treated expeditiously, delirium may be reversed in some patients. It is imperative that those caring for critically ill patients with cancer have the knowledge and tools necessary to identify and manage delirium appropriately. Although all critically ill patients are at risk for delirium, cancer presents additional assaults to the central nervous system via direct tumor invasion or iatrogenic provocations. This article describes delirium in cancer, and addresses diagnostic and management issues across the course of the disease.