Efficacy and safety of atypical antipsychotic drugs (quetiapine, risperidone, aripiprazole and paliperidone) compared with placebo or typical antipsychotic drugs for treating refractory schizophrenia: overview of systematic reviews

Pharmacokinetic Prediction of Immediate- and Extended-Release Tablets for Patients with Liver Disease Using Whole Body Physiologically-Based Pharmacokinetic Modeling for the Antipsychotic Drug Quetiapine

Although quetiapine metabolism occurs extensively in the liver and careful dosing is recommended in patients with liver disease, there has been a paucity of pharmacometric studies to adjust the clinical dose of quetiapine according to liver-disease severity. This study aimed to establish a whole-body, physiologically-based pharmacokinetic (WB-PBPK) model to explain interindividual variability in quetiapine PK and quantitatively predict PK in patients with liver disease. The developed WB-PBPK model well described the PK characteristics of different quetiapine regimens in healthy populations. The PK predictions could also be applied to patients with schizophrenia (without significant differences from healthy subjects). For the same total dose of quetiapine, both immediate-release (IR) and extended-release (ER) tablets showed significantly increased exposure and decreased clearance in patients with liver disease compared to healthy subjects. The model showed that steady-state plasma quetiapine concentrations exceeded the usual therapeutic range after multiple doses of IR tablets 250 mg three times daily or ER tablets 800 mg once daily in patients with liver disease. Therefore, the doses of quetiapine IR or ER tablets could be reduced by 0.10-0.50 times depending on liver-disease severity, so that mean steady-state plasma concentrations could be positioned near the therapeutic range. WB-PBPK modeling for quetiapine enabled quantitative prediction of PK according to IR or ER formulation and liver-disease severity. The results of this study provide useful data for improving the therapeutic use of quetiapine by enabling dose selection based on formulation and liver-disease severity.

Evidence for Therapeutic Drug Monitoring of Atypical Antipsychotics

Second-generation antipsychotics (SGAs), also known as atypical antipsychotics, are a newer class of antipsychotic drugs used to treat schizophrenia, bipolar disorder, and related psychiatric conditions. The plasma concentration of antipsychotic drugs is a valid measure of the drug at its primary target structure in the brain, and therefore determines the efficacy and safety of these drugs. However, despite the well-known high variability in pharmacokinetics of these substances, psychiatric medication is usually administered in uniform dosage schedules. Therapeutic drug monitoring (TDM), as the specific method that can help personalised medicine in dose adjustment according to the characteristics of the individual patient, minimizing the risk of toxicity, monitoring adherence, and increasing cost-effectiveness in the treatment, thus seems to be an elegant tool to solve this problem. Non-response to therapeutic doses, uncertain adherence to medication, suboptimal tolerability, or pharmacokinetic drug-drug interactions are typical indications for TDM of SGAs. This review aims to summarize an overview of the current knowledge and evidence of the possibilities to tailor the dosage of selected SGAs using TDM, including the necessary pharmacokinetic parameters for personalised pharmacotherapy.

Prescribing pattern of antipsychotics for patients with schizophrenia using the total daily dose online tool

This study aimed to investigate the prescribing pattern of antipsychotic medications for schizophrenia using the British National Formulary total daily dose (TDD) online tool. We analysed data from the electronic medical records at King Khalid University Hospital (KKUH) of 272 patients diagnosed with schizophrenia who were prescribed both typical and atypical antipsychotic medications. The results showed that aripiprazole was the most commonly prescribed antipsychotic drug, followed by haloperidol then risperidone. The TDD online tool was used to calculate the TDD of each prescribed antipsychotic medication. Most patients were prescribed doses within the recommended range for each medication, although some were prescribed doses above or below the recommended range. Moreover, a high recommended TDD was associated with the combined use of antipsychotics rather than monotherapy. Additionally, high TDD levels were associated with the following antipsychotics: haloperidol, olanzapine, paliperidone, and quetiapine. Our findings highlight the importance of using evidence-based tools such as the TDD online tool to guide prescribing practices and ensure optimal dosing of antipsychotic medications for patients with schizophrenia.

Database combinations to retrieve systematic reviews in overviews of reviews: a methodological study

Background

When conducting an Overviews of Reviews on health-related topics, it is unclear which combination of bibliographic databases authors should use for searching for SRs. Our goal was to determine which databases included the most systematic reviews and identify an optimal database combination for searching systematic reviews.

Methods

A set of 86 Overviews of Reviews with 1219 included systematic reviews was extracted from a previous study. Inclusion of the systematic reviews was assessed in MEDLINE, CINAHL, Embase, Epistemonikos, PsycINFO, and TRIP. The mean inclusion rate (% of included systematic reviews) and corresponding 95% confidence interval were calculated for each database individually, as well as for combinations of MEDLINE with each other database and reference checking.

Results

Inclusion of systematic reviews was higher in MEDLINE than in any other single database (mean inclusion rate 89.7%; 95% confidence interval [89.0–90.3%]). Combined with reference checking, this value increased to 93.7% [93.2–94.2%]. The best combination of two databases plus reference checking consisted of MEDLINE and Epistemonikos (99.2% [99.0–99.3%]). Stratification by Health Technology Assessment reports (97.7% [96.5–98.9%]) vs. Cochrane Overviews (100.0%) vs. non-Cochrane Overviews (99.3% [99.1–99.4%]) showed that inclusion was only slightly lower for Health Technology Assessment reports. However, MEDLINE, Epistemonikos, and reference checking remained the best combination. Among the 10/1219 systematic reviews not identified by this combination, five were published as websites rather than journals, two were included in CINAHL and Embase, and one was included in the database ERIC.

Conclusions

MEDLINE and Epistemonikos, complemented by reference checking of included studies, is the best database combination to identify systematic reviews on health-related topics.

Adherence, persistence, and inpatient utilization among adult schizophrenia patients using once-monthly versus twice-monthly long-acting atypical antipsychotics

AIMS

This study compared healthcare resource utilization (HRU), healthcare costs, adherence, and persistence among adult patients with schizophrenia using once-monthly (OM) vs twice-monthly (TM) atypical long-acting injectable (LAI) antipsychotic (AP) therapy.

MATERIALS AND METHODS

A longitudinal retrospective cohort study was conducted using Medicaid claims data from six states. Patients initiated on aripiprazole or paliperidone palmitate were assigned to the OM cohort; risperidone-treated patients were assigned to the TM cohort. HRU and healthcare costs were assessed during the first 12 months following stabilization on the medication. Adherence was measured using the proportion of days covered (PDC) during the first year of follow-up. Persistence to the index medication was measured during the first 2 years following the index date. Comparison between the cohorts was achieved using multivariable generalized linear models, adjusting for demographic and clinical characteristics.

RESULTS

Patients in the OM LAI cohort had lower inpatient HRU and medical costs when compared with patients in the TM cohort. Higher medical costs in the TM LAI cohort offset the higher pharmacy costs in the OM LAI cohort. Mean PDC during the first 12 months of follow-up was higher in the OM cohort than in the TM cohort (0.56 vs 0.50, p < .01). Median persistence was longer in the OM cohort than in the TM cohort (7.5 months vs 5.5 months), as was the hazard of discontinuing the index medication (hazard ratio = 0.83, p = .01). Kaplan-Meier rates of persistence at 1 year were higher for OM patients than for TM patients (37.6% vs 29.6%, p < .01).

LIMITATIONS

This was a Medicaid sample with few aripiprazole LAI patients (5.4% of OM cohort). Medication use was inferred from pharmacy claims.

CONCLUSIONS

Among Medicaid patients in these six states, OM AP treatment was associated with lower HRU, better adherence and persistence, and similar total costs compared to patients on TM treatment.

Determination of quetiapine in human plasma by LC-MS/MS and its application in a bioequivalence study

A selective, sensitive and simple high performance liquid chromatography tandem mass spectrometric (HPLC-MS/MS) method for determining quetiapine in human plasma was developed and validated. One-step protein precipitation with acetonitrile was used to pretreat plasma samples. Carbamazepine was used as internal standard. An automated liquid handling workstation with 96-well protein precipitate plate was used to facilitate the process. The chromatographic separation was achieved on a Waters Xbridge C₁₈ column (3.5μm, 2.1mm×50mm). Gradient elution was set with a mobile phase of acetonitrile/water (containing 10mM ammonium acetate and 0.1% formic acid).The flow rate was 0.4mL/min and total analytical run time was 3min. The analysis was conducted using a triple quadrupole tandem mass spectrometer with an electrospray ionization source operating in positive ion mode. The multiple reaction monitoring of transition were m/z 384.2→253.1 for quetiapine and m/z 237.0→194.0 for carbamazepine, respectively. The linear concentration range for the standard curve of quetiapine was 0.5-400ng/mL for a 5μL injection of the pretreated sample (original plasma sample, 50μL). The intra-day and inter-day accuracy and precision were all less than 15%. The method was successfully used in a bioequivalence study comparing two quetiapine extended-release tablets in Chinese volunteers.

The effect of brexpiprazole in adult outpatients with early-episode schizophrenia: an exploratory study

The aim of this study was to evaluate flexibly dosed brexpiprazole for early-episode schizophrenia through the assessment of efficacy, social functioning, and tolerability. This was an exploratory, 16-week, open-label, flexible-dose (1, 2, 3, or 4 mg/day; target dose 3 mg/day) study in outpatients with early-episode schizophrenia (18-35 years old, ≤5 years' duration of illness). Efficacy was assessed by the Positive and Negative Syndrome Scale score (PANSS) and social functioning was assessed by changes from baseline in PANSS modified prosocial subscale, personal and social performance (PSP), and specific levels of functioning (SLOF) scales. Safety and tolerability were also evaluated. Overall, 25/49 patients completed the study. Symptoms of schizophrenia improved over the entire treatment period, as evidenced by reductions in PANSS total score from baseline (least squares mean change at week 16: -10.2). Improvements in social functioning were shown by least squares mean changes from baseline at week 16 in the PANSS prosocial subscale (-2.0), PSP (6.6), and SLOF (13.1). Brexpiprazole was generally well tolerated; the most common adverse events were insomnia (7/49 patients), somnolence (4/49), sedation, weight increase, and nausea (each 3/49). Brexpiprazole may represent a novel and effective treatment strategy for patients with early-episode schizophrenia and may be effective for improving social function.

Dopamine Targeting Drugs for the Treatment of Schizophrenia: Past, Present and Future

Schizophrenia is a chronic and debilitating neuropsychiatric disorder affecting approximately 1% of the world's population. This disease is associated with considerable morbidity placing a major financial burden on society. Antipsychotics have been the mainstay of the pharmacological treatment of schizophrenia for decades. The traditional typical and atypical antipsychotics demonstrate clinical efficacy in treating positive symptoms, such as hallucinations and delusions, while are largely ineffective and may worsen negative symptoms, such as blunted affect and social withdrawal, as well as cognitive function. The inability to treat these latter symptoms may contribute to social function impairment associated with schizophrenia. The dysfunction of multiple neurotransmitter systems in schizophrenia suggests that drugs selectively targeting one neurotransmission pathway are unlikely to meet all the therapeutic needs of this heterogeneous disorder. Often, however, the unintentional engagement of multiple pharmacological targets or even the excessive engagement of intended pharmacological targets can lead to undesired consequences and poor tolerability. In this article, we will review marketed typical and atypical antipsychotics and new therapeutic agents targeting dopamine receptors and other neurotransmitters for the treatment of schizophrenia. Representative typical and atypical antipsychotic drugs and new investigational drug candidates will be systematically reviewed and compared by reviewing structure-activity relationships, pharmacokinetic properties, drug metabolism and safety, pharmacological properties, preclinical data in animal models, clinical outcomes and associated side effects.

Systematic Literature Review of the Methods Used to Compare Newer Second-Generation Agents for the Management of Schizophrenia: A focus on Health Technology Assessment

BACKGROUND

The challenges of comparative effectiveness to support health technology assessment (HTA) agencies are important considerations in the choices of antipsychotic medications for the treatment of schizophrenia.

OBJECTIVES

Our aim was to assess the study methods used and outcomes reported in the published literature to address the question of comparative effectiveness of newer antipsychotic agents and the adequacy and availability of evidence to support HTA agencies.

DATA SOURCE

A systematic search of the PubMed database from 1 January 2009 to 30 September 2013 was conducted to identify studies evaluating new atypical antipsychotics reporting on comparative effectiveness.

STUDY SELECTION

The systematic review comprised of studies on schizophrenia patients where at least two drugs were being compared and at least one treatment group received one of the following second-generation antipsychotics: risperidone, olanzapine, aripiprazole, paliperidone, asenapine, iloperidone, lurasidone, and quetiapine. The included studies were also required to have an efficacy, safety or economic outcome, such as Positive and Negative Syndrome Scale (PANSS) score, weight gain, resource utilization, or costs.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two reviewers (BW and GK) independently applied the inclusion criteria. Disagreements between reviewers were resolved by consensus, referring to the original sources. Information on the methodology and outcomes was collected for each included study. This included study description, head-to-head drug comparison, patient population, study methodology, statistical methods, reported outcomes, study support, and journal type.

RESULTS

A total of 198 studies were identified from electronic search methods. The largest category of studies was randomized controlled trials [RCTs] (N = 73; 36.9%), which were largely directed at the regulatory endpoint. Fewer studies were undertaken for HTA-purposes cohort studies (N = 53; 26.8%), meta-analyses (N = 32; 16.2%), economic studies (N = 14; 7.1%), and cross-sectional studies (N = 13; 6.6%). Direct head-to-head comparisons preferred by HTA were dominated by the comparison involving olanzapine and risperidone, representing 149 (75.3%) and 119 (60.1%) studies, respectively. RCTs, which are the primary study type for regulatory submissions, showed a lack of bias. Studies aimed at HTA were not as well performed. Cohort studies suffered from bias in the selection of comparison groups, lack of control for confounders, and differential dropout rates. As a group, cross-sectional studies scored poorly for bias, with a primary failure to identify a representative sample. Economic studies showed highly variable bias, with bias in the representation of effectiveness data, model assumptions without validation, and lack of sensitivity analyses.

LIMITATIONS

One limitation of this systematic review is that it only included studies from 2009 to 2013, potentially excluding some earlier comparator studies, particularly those involving first-generation antipsychotics.

CONCLUSIONS

This review of comparative effectiveness studies of second-generation antipsychotic agents for schizophrenic patients revealed a wide range of study types, study methodologies, and outcomes. For traditional efficacy outcomes and select safety outcomes, there is strong evidence from many well-conducted studies; however, there are fewer studies of types preferred by HTA with limited head-to-head comparisons and a higher risk of bias in the execution of these studies.

A six month randomized controlled trial of long acting injectable risperidone 50 and 100mg in treatment resistant schizophrenia

It has been suggested that atypical antipsychotic drugs (A-APDs) other than clozapine may be effective to improve positive symptoms in some patients with treatment resistant schizophrenia (TRS), if both the dose is higher, and the duration of the trial longer, than those which have been ineffective in non-TRS (NTRS) patients. This hypothesis was tested with long acting injectable risperidone (Risperdal Consta®, RLAI). One hundred sixty TRS patients selected for persistent moderate-severe delusions or hallucinations, or both, were randomized to RLAI, 50 or 100mg biweekly, in a six month, outpatient, double-blind, multicenter trial. We hypothesized that RLAI, 100mg, would be more effective than RLAI, 50mg. However, both doses produced clinically significant and equivalent improvement in PANSS Total, Positive, and Negative subscale scores, as well as key cognitive, global and functional measures, with increasing response during the course of the study, confirming the value of longer clinical trial duration for patients with TRS, but not superiority of the higher dose. The overall response rate was comparable to that previously reported for clozapine and high dose olanzapine, another A-APD, in TRS. Both doses of RLAI were equally well tolerated, producing minimal extrapyramidal side effects and few drop outs. Plasma levels of the active moiety, risperidone+9-hydroxyrisperidone, during treatment with RLAI 100mg, were comparable to those for 6-8 mg/day oral risperidone, which have not been effective in TRS. Further study of RLAI, ≥ 50-100mg biweekly, should compare it with clozapine and oral risperidone in TRS, with duration of treatment ≥ six months.

Effect of combination of aripiprazole with carbamazepine and fluvoxamine on liver functions in experimental animals

Objectives:

Aripiprazole, a new atypical antipsychotic drug extensively metabolized by enzyme CYP3A4, is found to produce asymptomatic elevation of serum transaminase levels on long-term treatment. The present study aims to evaluate the hepatotoxic effect of aripiprazole when coprescribed with carbamazepine and fluvoxamine.

Materials and Methods:

The rats were subjected to chronic treatment with two different doses, therapeutic dose (TD) and maximum therapeutic dose (MTD), of aripiprazole in combination with carbamazepine and fluvoxamine. The changes in hepatic function was assessed by various biochemical liver enzyme markers like serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), total bilirubin, histological studies, and physical parameters (liver weight, liver volume, and body weight).

Results:

The combination of aripiprazole with fluvoxamine at both TD and MTD showed the hepatic damage and significant elevation in serum transaminase level which is supported by histological reports. The coadministration of aripiprazole with carbamazepine leads to significant decrease in blood concentration of aripiprazole possibly due to induction of enzyme CYP3A4 resulting in loss or reduction of clinical efficacy.

Conclusions:

There would be an accumulation of aripiprazole when coadministered with fluvoxamine, a known inhibitor of CYP3A4, leading to hepatic damage and reduction in aripiprazole when administered along with carbamazepine. Therefore, aripiprazole with fluvoxamine and carbamazepine should be coprescribed with caution. The patients should be monitored for signs of adverse effects like hepatic damage or decreased efficacy of these drugs.

Antipsychotic treatments; focus on lurasidone

The introduction of atypical antipsychotic drugs (AAPDs), or second-generation antipsychotics, with clozapine as the prototype, has largely changed the clinicians' attitudes toward the treatment of mental illnesses including, but not limited to schizophrenia. Initially, there was optimism that AAPDs would be superior over typical antipsychotic drugs (TAPDs), or first-generation antipsychotic drugs, in terms of efficacy in various phenomenological aspects, including cognitive impairment, and less likelihood of causing adverse events. However, these views have been partly challenged by results from recent meta-analysis studies. Specifically, cardio-metabolic side effects of AAPDs, in spite of a relative paucity of extrapyramidal symptoms, may sometimes limit the use of these agents. Accordingly, attempts have been made to develop newer compounds, e.g., lurasidone, with the aim of increasing efficacy and tolerability. Further investigations are warranted to determine if a larger proportion of patients will be benefitted by treatment with AAPDs compared to TAPDs in terms of remission and recovery.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Role of aripiprazole in treatment-resistant schizophrenia

About one third of patients with schizophrenia respond unsatisfactorily to antipsychotic treatment and are termed "treatment-resistant". Clozapine is still the gold standard in these cases. However, 40%-70% of patients do not improve sufficiently on clozapine either. In the search for more efficacious strategies for treatment-resistant schizophrenia, drugs with different pharmacological profiles seem to raise new hopes, but are they valid? The aim of this review was to evaluate the evidence for aripiprazole as a potential strategy in monotherapy or combination therapy for patients with treatment-resistant schizophrenia. The evidence for aripiprazole monotherapy and for the combination of aripiprazole with psychotropics other than clozapine is scant, and no recommendation can be made on the basis of the currently available data. More effort has been made in describing combinations of aripiprazole and clozapine. Most of the open-label and case studies as well as case reports have shown positive effects of this combination on overall psychopathology and to some extent on negative symptoms. Several reports describe the possibility of dose reduction for clozapine in combination with aripiprazole, a strategy that might help so-called "treatment-intolerant" patients. The findings of four randomized controlled trials with respect to changes in psychopathology seem less conclusive. The most commonly found beneficial effects are better metabolic outcomes and indicators of the possibility of reducing the clozapine dose. However, other side effects, such as akathisia, are repeatedly reported. Further, none of the studies report longer-term outcomes. In the absence of alternatives, polypharmacy is a common strategy in clinical practice. Combining aripiprazole with clozapine in clozapine-resistant or clozapine-intolerant patients seems to be worthy of further investigation from the pharmacological and clinical points of view.

[Evidence-based practices published in Brazil: identification and analysis of their types and methodological approches]

This is an integrative review of Brazilian studies on evidence-based practices (EBP) in health, published in ISI/JCR journals in the last 10 years. The aim was to identify the specialty areas that most accomplished these studies, their foci and methodological approaches. Based on inclusion criteria, 144 studies were selected. The results indicate that most EBP studies addressed childhood and adolescence, infectious diseases, psychiatrics/mental health and surgery. The predominant foci were prevention, treatment/rehabilitation, diagnosis and assessment. The most used methods were systematic review with or without meta-analysis, protocol review or synthesis of available evidence studies, and integrative review. A strong multiprofessional expansion of EBP is found in Brazil, contributing to the search for more selective practices by collecting, recognizing and critically analyzing the produced knowledge. The study also contributes to the analysis itself of ways to do research and new research possibilities.