The evolution of antipsychotic switch and polypharmacy in natural practice--a longitudinal perspective

Predictors of antipsychotics switching among ambulatory patients with schizophrenia in Ethiopia: a multicenter hospital-based cross-sectional study

INTRODUCTION

A change of therapy from one to another antipsychotic medication is currently the main challenge of therapy. This study aimed to assess the prevalence of antipsychotic medication switches and determinants among patients with schizophrenia in Northwest Ethiopia.

METHODS

Multi-center hospital-based cross-sectional study was conducted at five Comprehensive Specialized Hospitals found in Northwest Ethiopia from April 30, 2021, to August 30, 2021. Data were extracted from both patients' medical charts and interviews. Data were entered into Epi-data software version 3.5.1 and exported to SPSS version 25.0 for analysis. A multivariable logistic regression model was fitted to identify factors associated with medication regimen switch. The level of significance of the study was kept at a p-value of 0.05 with a 95% confidence interval.

RESULT

A total of 414 patients are involved in the study, and 188 (45.5%) of patients switched antipsychotics within one year. The unavailability of the medication is the commonest reason for switching. Being male [AOR = 2.581, 95% CI (1.463, 4.552)], having relapse [AOR = 2.341,95% CI (1.169,4.687)], history of hospitalization in the past year [AOR = 3.00,95% CI (1.478,5.715)] and taking typical antipsychotics [AOR = 3.340, CI (1.76, 6.00)] had a significant association with antipsychotics switching.

CONCLUSIONS AND RECOMMENDATIONS

There is a high prevalence of antipsychotic switches among schizophrenia patients. Prescribers need to be careful while dosing, selecting, and switching antipsychotics, hence may help reduce discontinuation and unnecessary switch and thus achieve optimal clinical management.

Global Neuropsychopharmacological Prescription Trends in Adults with Schizophrenia, Clinical Correlates and Implications for Practice: A Scoping Review

It is important to examine the psychotropic prescription practices in schizophrenia, as it can inform regarding changing treatment choices and related patient profiles. No recent reviews have evaluated the global neuropsychopharmacological prescription patterns in adults with schizophrenia. A systematic search of the literature published from 2002 to 2023 found 88 empirical papers pertinent to the utilization of psychotropic agents. Globally, there were wide inter-country and inter-regional variations in the prescription of psychotropic agents. Overall, over time there was an absolute increase in the prescription rate of second-generation antipsychotics (up to 50%), mood stabilizers (up to 15%), and antidepressants (up to 17%), with an observed absolute decrease in the rate of antipsychotic polypharmacy (up to 15%), use of high dose antipsychotic (up to 12% in Asia), clozapine (up to 9%) and antipsychotic long-acting injectables (up to 10%). Prescription patterns were mainly associated with specific socio-demographic (such as age), illness (such as illness duration), and treatment factors (such as adherence). Further work, including more evidence in adjunctive neuropsychopharmacological treatments, pharmaco-economic considerations, and examination of cohorts in prospective studies, can proffer insights into changing prescription trends relevant to different treatment settings and predictors of such trends for enhancement of clinical management in schizophrenia.

Magnetic resonance imaging detects white adipose tissue beiging in mice following PDE10A inhibitor treatment

Weight gain is a common harmful side effect of atypical antipsychotics used for schizophrenia treatment. Conversely, treatment with the novel phosphodiesterase-10A (PDE10A) inhibitor MK-8189 in clinical trials led to significant weight reduction, especially in patients with obesity. This study aimed to understand and describe the mechanism underlying this observation, which is essential to guide clinical decisions. We hypothesized that PDE10A inhibition causes beiging of white adipose tissue (WAT), leading to weight loss. Magnetic resonance imaging (MRI) methods were developed, validated, and applied in a diet-induced obesity mouse model treated with a PDE10A inhibitor THPP-6 or vehicle for measurement of fat content and vascularization of adipose tissue. Treated mice showed significantly lower fat fraction in white and brown adipose tissue, and increased perfusion and vascular density in WAT versus vehicle, confirming the hypothesis, and matching the effect of CL-316,243, a compound known to cause adipose tissue beiging. The in vivo findings were validated by qPCR revealing upregulation of Ucp1 and Pcg1-α genes, known markers of WAT beiging, and angiogenesis marker VegfA in the THPP-6 group. This work provides a detailed understanding of the mechanism of action of PDE10A inhibitor treatment on adipose tissue and body weight and will be valuable to guide both the use of MK-8189 in schizophrenia and the potential application of the target for weight loss indication.

Cross-sectional and longitudinal assessment of the association between DDR1 variants and processing speed in patients with early psychosis and healthy controls

Recent evidence indicates that DDR1 participates in myelination and that variants of DDR1 are associated with decreased cognitive processing speed (PS) in schizophrenia (SZ). Here, we explored whether DDR1 variants were associated with PS in subjects diagnosed with an early psychosis (EP), a condition often preceding SZ. Data from two Spanish independent samples (from Reus and Santander) including patients with EP (n = 75 and n = 312, respectively) and healthy controls (HCs; n = 57 and n = 160) were analyzed. The Trail Making Test part A was used to evaluate PS. Participants underwent genotyping to identify DDR1 variants rs1264323 and rs2267641. Cross-sectional data were analyzed with general linear models and longitudinal data were analyzed using mixed models. We examined the combined rs1264323AA-rs2267641AC/CC genotypes (an SZ-risk combination) on PS. The SZ-risk combined genotypes were associated with increased PS in EP patients but not in HCs in the cross-sectional analysis. In the longitudinal analysis, the SZ-risk combined genotypes were significantly associated with increased PS in both HCs and EP patients throughout the 10-year follow-up but no genotype × time interaction was observed. These results provide further evidence that DDR1 is involved in cognition and should be replicated with other samples.

Discovery of MK-8189, a Highly Potent and Selective PDE10A Inhibitor for the Treatment of Schizophrenia

PDE10A is an important regulator of striatal signaling that, when inhibited, can normalize dysfunctional activity. Given the involvement of dysfunctional striatal activity with schizophrenia, PDE10A inhibition represents a potentially novel means for its treatment. With the goal of developing PDE10A inhibitors, early optimization of a fragment hit through rational design led to a series of potent pyrimidine PDE10A inhibitors that required further improvements in physicochemical properties, off-target activities, and pharmacokinetics. Herein we describe the discovery of an isomeric pyrimidine series that addresses the liabilities seen with earlier compounds and resulted in the invention of compound 18 (MK-8189), which is currently in Phase 2b clinical development for the treatment of schizophrenia.

Exploring Hidden Issues in the Use of Antipsychotic Polypharmacy in the Treatment of Schizophrenia

The mainstay of schizophrenia treatment is pharmacological therapy using various antipsychotics including first- and second-generation antipsychotics which have different pharmacokinetic and pharmacodynamic property leading to differential presentation of adverse events (AEs) and treatment effects such as negative symptoms, cognitive symptoms and cormorbid symptoms. Major treatment guidelines suggest the use of antipsychotic monotherapy (APM) as a gold standard in the treatment of schizophrenia. However, the effects of APM is inadequate and less potent to achieve symptom remission as well as functional recovery in real practice which has been consistently reported in numerous controlled clinical trials, large practical trials, independent small studies and systematic reviews till today. Therefore anti-psychotic polypharmacy (APP) regardless of the class of antipsychotics has been also commonly utilized for many reasons in real world practice. However, APP has also crucial pitfalls including increase of total psychotics including antipsychotics, high-doses of antipsychotics used, poor compliance, drug-drug interaction and risks for developing AEs, all of which are paradoxically related to poor clinical outcomes, whereas APP has also substantial advantages in reduction of re-hospitalization, severe psychopathology and targeted control of concurrent symptoms. Given currently limited therapeutic options, it is also important to properly utilize APP in order to maximize its clinical utility and minimize its risk for better treatment outcomes for patients with schizophrenia, based on risk/benefit with full understanding of pharmacological and clinical issues on APP. The present paper intends to address intriguing and important issues in the use of APP in real world practice.

Characteristics of discharge prescriptions for patients with schizophrenia or major depressive disorder: Real-world evidence from the Effectiveness of Guidelines for Dissemination and Education (EGUIDE) psychiatric treatment project

BACKGROUND

Monopharmacy with antipsychotics and antidepressants is the first-line treatment for schizophrenia and major depressive disorder (MDD) in most clinical guidelines, while polypharmacy with psychotropic agents in the treatment of schizophrenia is common in clinical practice. There are no detailed data on the prescription patterns for inpatients with mental illness with reliable diagnoses made by treating psychiatrists.

METHODS

We gathered prescription data at discharge from 2177 patients with schizophrenia and 1238 patients with MDD from October 2016 to March 2018.

RESULTS

The patients with schizophrenia aged between 60 and 79 were prescribed lower doses of antipsychotics and hypnotics/anxiolytics than those aged between 40 and 59. There were significant differences between the prescription rate of antipsychotics in the patients with schizophrenia and that of antidepressants in the patients with MDD. The frequency of concomitant drugs such as anti-Parkinson drugs, anxiolytics/hypnotics and mood stabilizers in the subjects with schizophrenia prescribed antipsychotic polypharmacy was significantly higher than that with monotherapy. For the patients with schizophrenia, olanzapine, risperidone, aripiprazole, quetiapine, and blonanserin were the five most prescribed antipsychotics. For the patients with MDD, mirtazapine, duloxetine, escitalopram, trazodone and sertraline were the five most prescribed antidepressants.

CONCLUSIONS

Our results showed the use of high doses of antipsychotics, high percentages of antipsychotic polypharmacy and concurrent use of hypnotics/anxiolytics in patients with schizophrenia. Notably, these data were collected before intensive instruction regarding the guidelines; therefore, we need to assess the change in the prescription pattern post guideline instruction.

Clozapine affects the pharmacokinetics of risperidone and inhibits its metabolism and P-glycoprotein-mediated transport in vivo and in vitro: A safety attention to antipsychotic polypharmacy with clozapine and risperidone

Antipsychotic polypharmacy (APP), as one maintenance treatment strategy in patients with schizophrenia, has gained popularity in real-world clinical settings. Risperidone (RIS) and clozapine (CLZ) are the most commonly prescribed second-generation antipsychotics, and they are often used in combination as APP. In this study, the pharmacokinetics of RIS and CLZ in rats were examined after co-administration to explore the reliability and rationality of co-medication with RIS and CLZ. In addition, the effects of CLZ on RIS metabolism and transport in vitro were investigated. The results illustrated that in the 7-day continuous administration test in rats, when co-administered with CLZ, the area under curve and peak concentrations of RIS were increased by 2.2- and 3.1-fold at the first dose, respectively, increased by 3.4- and 6.2-fold at the last dose, respectively. The metabolite-to-parent ratio of RIS was approximately 22% and 33% lower than those of RIS alone group at the first and last doses, respectively. Moreover, CLZ significantly increased RIS concentrations in the brain (3.0-4.8 folds) and cerebrospinal fluid (2.1-3.5 folds) in rats, which was slightly lower than the impact of verapamil on RIS after co-medication. Experiments in vitro indicated that CLZ competitively inhibited the conversion of RIS to 9-hydroxy-RIS with the inhibition constants of 1.36 and 3.0 μM in rat and human liver microsomes, respectively. Furthermore, the efflux ratio of RIS in Caco-2 monolayers was significantly reduced by CLZ at 1 μM. Hence, CLZ may affect the exposure of RIS by inhibiting its metabolism and P-glycoprotein-mediated transport. These findings highlighted that APP with RIS and CLZ might increase the plasma concentrations of RIS and 9-hydroxy-RIS beyond the safety ranges and cause toxic side effects.

Switching to antipsychotic monotherapy vs. staying on antipsychotic polypharmacy in schizophrenia: A systematic review and meta-analysis

BACKGROUND

While recent meta-analyses have reported the superiority of antipsychotic polypharmacy (APP) over antipsychotic monotherapy (APM) in schizophrenia, switching to APM can be beneficial in terms of side effects. To determine whether patients receiving APP should switch to APM or stay on APP, we conducted a systematic review and meta-analysis.

METHODS

Randomized controlled trials (RCTs) examining a switch from APP to APM vs. staying on APP were systematically selected from a previous meta-analysis comparing APP with APM in patients with schizophrenia. In addition, we conducted an updated systematic literature search using MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Data on study discontinuation, relapse, psychopathology, neurocognition, extrapyramidal symptoms, and body weight/body mass index (BMI) were extracted and synthesized.

RESULTS

A total of 6 RCTs involving 341 patients were included. All studies examined a switch from 2 antipsychotic agents to a single agent. Clozapine-treated patients were included in 3 studies. There was a significant difference in study discontinuation due to all causes in favor of staying on APP (N = 6, n = 341, RR = 2.28, 95% CI = 1.50-3.46, P < 0.001). There were no significant differences in relapse, any psychopathology, neurocognition, extrapyramidal symptoms, or body weight/BMI between the 2 groups. The quality of evidence was low to very low.

CONCLUSIONS

The findings suggest that clinicians should closely monitor patient condition when switching to APM after receiving 2 antipsychotics. Given the low to very low overall quality of the evidence, the findings should be considered preliminary and inconclusive.

Antipsychotic polypharmacy in the treatment of schizophrenia in China and Japan

BACKGROUND

Although antipsychotic monotherapy is recommended as the main treatment for schizophrenia, antipsychotic polypharmacy is not rare in practice. However, longitudinal data on antipsychotic polypharmacy in schizophrenia treatment are limited.

METHODS

This longitudinal database study described antipsychotic polypharmacy in the treatment of schizophrenia in real-world settings in China and Japan. We retrieved information about antipsychotic treatment for schizophrenia from January 2010 to December 2014 from two hospital Electronic Medical Records databases in China and one claims database, Japan Medical Data Centre in Japan. Eligible patients had a diagnosis of schizophrenia (International Classification of Diseases, Tenth Revision F20.x) and at least one prescription for first or second generation antipsychotics. Antipsychotic polypharmacy was defined as having more than one antipsychotic medication overlapping for ⩾60 days. The Japan Medical Data Centre study cohort was further stratified by employees (insurance beneficiaries) and their dependents.

RESULTS

The study cohorts comprised 11,961 patients from China and 25,034 (10,661 employee sub-cohort and 14,373 dependent sub-cohort) from 14 days Japan Medical Data Centre in Japan. Most patients were prescribed monotherapy (87.3% in China and 80.1% in Japan), of which oral second-generation antipsychotics were the majority (78.9% in China and 65.8% in Japan). The prevalence rate of antipsychotic polypharmacy was 12.7% in China and 19.9% in Japan (13.7% in employees vs 24.5% in dependents). The most common combinations were two oral antipsychotics. Combinations of more than two drugs were uncommon in China (0.3%) but were prescribed for 5.3% of patients in Japan. Among patients treated with monotherapy, 12.6/100 person-years (11.8%) in China and 9.6/100 person-years (11.0%) in Japan switched to antipsychotic polypharmacy during follow-up. Younger patients were more likely to switch to antipsychotic polypharmacy than older patents in all study cohorts.

CONCLUSION

The observed rates of antipsychotic polypharmacy ranged from 12.7% in China to 19.9% in Japan. Switching from monotherapy to antipsychotic polypharmacy was most likely to occur in younger patients with schizophrenia.

Acupuncture as Add-On Treatment of the Positive, Negative, and Cognitive Symptoms of Patients with Schizophrenia: A Systematic Review

Background: Schizophrenia is a severe psychiatric disorder that has a large impact on patients' lives. In addition to Western medicine, the use of additional treatments, such as acupuncture, in treating the positive, negative, and cognitive symptoms is increasing. Methods: We conducted a systematic review on the use of acupuncture as an add-on treatment for patients with schizophrenia that are in regular care, with a special focus on the treatment of the often accompanying sleep disorders. In this study, we searched the Medline, ScienceDirect, Cochrane Library, Scopus, and ERIC databases with a cut-off date of 31 December 2017, thereby following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol. Results: Our search resulted in 26 eligible studies with 1181 patients with schizophrenia who received acupuncture treatment. Most studies showed limited evidence for the use of acupuncture as add-on therapy in the treatment of the positive, negative, and cognitive symptoms, but beneficial effects have been reported in the treatment of the accompanying sleep disorders. Conclusions: Limited evidence was found for the use of acupuncture as add-on therapy in the treatment of patients with schizophrenia; however, positive results were found in the treatment of sleep disorders, but this result needs to be confirmed in large, randomized, controlled trials.

Combination Antipsychotic Therapies: An Analysis From a Longitudinal Pragmatic Trial

BACKGROUND

Combination antipsychotics (CAs) are prescribed in schizophrenia despite limited evidence of efficacy. To explore the effect of switching from CA to monotherapy, we performed an exploratory analysis of the PROACTIVE (Preventing Relapse in Schizophrenia: Oral Antipsychotics Compared with Injectables: Evaluating Efficacy) study data, in which 305 patients with schizophrenia and schizoaffective disorder were followed for 30 months after randomization to long-acting injectable (LAI) risperidone or second-generation oral antipsychotic (OA).

METHODS

Patients who entered the PROACTIVE study on CA (n = 50), LAI (n = 20), or OA (n = 206) were compared in terms of time to relapse and clinical measures.

FINDINGS

The OA group had significantly fewer hospitalizations than the CA group (P = 0.009) at baseline. In the CA group, 68% patients relapsed versus 53% in the LAI, and 52% in the OA groups. Although there was no significant difference in the relapse rate among groups on χ test (χ = 3.85, P = 0.146), the log-rank test showed a significant difference among the groups in time to first relapse (χ = 6.81, P = 0.033), with significantly longer time to relapse in the OA group (mean, 562.8 days) than in the CA group (mean, 409.5; P = 0.011). The LAI group's mean time to first relapse (594 days) was not significantly different from the other groups. However, after adjusting for number of hospitalizations, group was no longer significant (hazard ratio, 1.541; P = 0.052).

IMPLICATIONS

Based on our exploratory analysis, taking antipsychotic combinations predicts earlier relapse and calls for additional treatment guidance in schizophrenia.

Patients' Knowledge about Prescribed Antipsychotics and Medication Adherence in Schizophrenia: A Cross-Sectional Survey

Introduction Data on the knowledge about antipsychotic medications prescribed in patients with schizophrenia are very limited. Moreover, it remains unclear how patients' knowledge about prescribed antipsychotics affects medication adherence. Methods ighty-one Japanese outpatients with schizophrenia according to the International Classification of Diseases, 10th edition, were included. Patients' knowledge of the primary antipsychotics prescribed to them in terms of therapeutic effects, type, and implicated neurotransmitters was assessed with a multiple-choice questionnaire developed for this study. Medication possession ratios (MPRs) were compared between patients who answered correctly and those who did not in each category. Results The percentages of subjects who answered correctly regarding antipsychotic effects, type, and implicated neurotransmitters were low at 30.9%, 30.9%, and 7.4%, respectively. No differences were found in MPRs between subjects who answered correctly and those who did not. Discussion Our preliminary results indicate that patients lack knowledge about their antipsychotic medications. More concerning, they suggest that knowledge about prescribed antipsychotics may not directly translate into actual medication adherence in patients with schizophrenia.

Trends in antipsychotic prescriptions for Japanese outpatients during 2006-2012: a descriptive epidemiological study

PURPOSE

This study aimed to assess the trends in antipsychotic prescriptions for outpatients in Japan, where a community-based approach to mental healthcare is emphasized.

METHODS

This descriptive epidemiological study used claims data from 1038 community pharmacies across Japan. Outpatients who were ≥18 years old and receiving their initial antipsychotic prescription during 2006-2012 were evaluated. The annual trends were reported for monotherapies, polypharmacy, antipsychotic doses, and the concurrent prescription of psychotropic medications.

RESULTS

The 152 592 outpatients included 101 133 (66%) adults (18-64 years old) and 51 459 (34%) older adults (≥65 years old). Among the adults, second-generation antipsychotic monotherapy prescriptions increased from 49% in 2006 to 71% in 2012, first-generation antipsychotic monotherapy prescriptions decreased from 29 to 14%, and antipsychotic polypharmacy decreased from 23 to 15%, respectively. Among the older adults, second-generation antipsychotic monotherapy prescriptions increased from 64 to 82%, first-generation antipsychotic monotherapy prescriptions decreased from 29 to 12%, and antipsychotic polypharmacy decreased from 7 to 6%, respectively. During the study period, >80% of the adults and >90% of the older adults received antipsychotics at risperidone-equivalent doses of <6 mg/day. Anxiolytics/hypnotics, antidepressants, antiparkinson agents, mood stabilizers, and anti-dementia agents were concurrently prescribed with antipsychotics for 70, 33, 20, 20, and 0.3% of the adults and for 43, 16, 19, 8, and 16% of the older adults, respectively.

CONCLUSIONS

The present study evaluated large-scale claims-based datasets and found that high-dose prescriptions and antipsychotic polypharmacy among Japanese outpatients were not as prevalent as has been previously thought. Copyright © 2017 John Wiley & Sons, Ltd.

Attitudes towards and rationale for antipsychotic polypharmacy among psychiatrists in Nigeria: Characteristics associated with high reported antipsychotic polypharmacy

Antipsychotic polypharmacy (APP) is commonplace despite lacking evidence of its effectiveness. We aimed to identify psychiatrists' rationale for and attitudes towards APP and to determine if attitudes influence antipsychotic polypharmacy prescription rates in a survey of a nationally representative sample of Nigerian psychiatrists (of which a majority were senior trainees: 74.2%). Prescriber characteristics, practices and attitudes were compared in 'high' (>30%) vs. 'low' (≤30%) antipsychotic polypharmacy prescribers and results were adjusted for multiple comparisons. Altogether, prescribers reported utilizing antipsychotic polypharmacy in 36.2% of their patients. Compared to 'low' antipsychotic polypharmacy prescribers, 'high' prescribers were significantly more likely using first-generation antipsychotics (FGA) combination, to have attempted a switch to monotherapy in less patients, or been successful in doing so. 'High' and 'low' antipsychotic polypharmacy prescribers were equally moderately concerned about the effects of antipsychotic polypharmacy and also did not differ regarding reasons not justifying antipsychotic polypharmacy. In a multivariable, backward elimination logistic regression model, 'low' antipsychotic polypharmacy was associated with having successfully switched patients to monotherapy, whereas the 'high' antipsychotic polypharmacy was associated with preferring FGA+FGA combinations and aiming for a reduction of non-antipsychotic medications. Antipsychotic polypharmacy is common among psychiatrists in Nigeria, with 'high' and 'low' antipsychotic polypharmacy prescribers sharing similar concerns/attitudes, but differing regarding their primary aim for antipsychotic polypharmacy and in their specific antipsychotic polypharmacy use characteristics.

Behavioral and qEEG effects of the PDE10A inhibitor THPP-1 in a novel rhesus model of antipsychotic activity

RATIONALE

Much preclinical data, almost exclusively using rodent, supports the notion that phosphodiesterase 10A (PDE10A) inhibition may offer an alternative to the current standard of care in schizophrenia. However, concerns persist regarding the clinical translatability of these models for newer drug classes like PDE10A inhibitors.

OBJECTIVES

We therefore sought to characterize the clinical standard risperidone and the PDE10A inhibitor THPP-1 in nonhuman primate, both alone and when used as a combination therapy.

METHODS

THPP-1 and risperidone were tested in a novel rhesus model of stimulant-induced motor activity (SIMA) and in rhesus electroencephalography (EEG).

RESULTS

Consistent with rodent data, both THPP-1 and risperidone significantly attenuated the stimulant effects in SIMA when administered alone, though some differences were noted. Combination therapy with a low dose of risperidone produced significantly more robust effects. THPP-1 and risperidone also produced a marked reduction of wake cycle time and gamma frequency power in EEG. However, THPP-1 differed from risperidone by reducing spectral power of lower frequencies (delta).

CONCLUSIONS

SIMA results suggest that PDE10A inhibition produces antipsychotic-like effects in higher species, and that combination therapy with PDE10A inhibitors may produce more robust efficacy compared to monotherapies. EEG and qEEG results confirm that PDE10A inhibition does share some central signaling effects with clinically effective antipsychotics. The present combination therapy results may carry implications for the manner in which clinical testing of PDE10A inhibitors is conducted.

Antipsychotic Medication Prescribing Practices Among Adult Patients Discharged From State Psychiatric Inpatient Hospitals

OBJECTIVES

The goal of this study was to explore antipsychotic medication prescribing practices in a sample of 86,034 patients discharged from state psychiatric inpatient hospitals and to find the prevalence of patients discharged with no antipsychotic medications, on antipsychotic monotherapy, and on antipsychotic polypharmacy. For patients discharged on antipsychotic polypharmacy, the study explored the adjusted rates of antipsychotic polypharmacy, the reasons patients were discharged on antipsychotic polypharmacy, the proportion of antipsychotic polypharmacy by mental health disorder, and the characteristics associated with being discharged on antipsychotic polypharmacy.

METHODS

This cross-sectional study analyzed all discharges for adult patients (18 to 64 y of age) from state psychiatric inpatient hospitals between January 1 and December 31, 2011. The relationship among variables was explored using χ, t test, and analysis of variance. Logistic regression was used to determine predictors of antipsychotic polypharmacy.

RESULTS

The prevalence of antipsychotic polypharmacy was 12%. Of the discharged patients receiving at least 1 antipsychotic medication (adjusted rate), 18% were on antipsychotic polypharmacy. The strongest predictors of antipsychotic polypharmacy being prescribed were having a diagnosis of schizophrenia and a length of stay of 90 days or more. Patients were prescribed antipsychotic polypharmacy primarily to reduce their symptoms.

CONCLUSIONS

Antipsychotic polypharmacy continues at a high enough rate to affect nearly 10,000 patients with a diagnosis of schizophrenia each year in state psychiatric inpatient hospitals. Further analysis of the clinical presentation of these patients may highlight particular aspects of the illness and its previous treatment that are contributing to practices outside the best-practice guideline. An increased understanding of trend data, patient characteristics, and national benchmarks provides an opportunity for decision-making that is sensitive to the patient's needs and cognizant of the hospital's accomplishments in adopting best practices.

A Flexible-Dose Study of Paliperidone ER in Patients With Nonacute Schizophrenia Previously Treated Unsuccessfully With Oral Olanzapine

OBJECTIVE

The goal of this study was to explore the tolerability, safety, and treatment response of switching from oral olanzapine to paliperidone extended release (ER).

METHODS

Adult patients with nonacute schizophrenia who had been treated unsuccessfully with oral olanzapine were switched to flexible doses of paliperidone ER (3 to 12 mg/d). The primary efficacy outcome was a ≥ 20% improvement in Positive and Negative Syndrome Scale (PANSS) total scores from baseline to endpoint for patients who switched medications because of lack of efficacy with olanzapine and noninferiority versus previous olanzapine treatment (mean endpoint change in PANSS total scores vs. baseline of ≤ 5 points) for patients who switched for reasons other than lack of efficacy. Safety and tolerability were assessed by monitoring adverse events, extrapyramidal symptoms, and weight change.

RESULTS

Of 396 patients, 65.2% were men, mean age was 40.0 ± 12.0 years, and 75.5% had paranoid schizophrenia. Among the patients whose main reason for switching was lack of efficacy, an improvement in the PANSS total score of ≥ 20% occurred in 57.4% of patients. Noninferiority was confirmed for each subgroup of patients whose main reason for switching was something other than lack of efficacy. Paliperidone ER was generally well tolerated. Extrapyramidal symptoms as measured by total Extrapyramidal Symptom Rating Scale scores showed statistically significant and clinically relevant improvements at endpoint, the average weight decreased by 0.8 ± 5.2 kg at endpoint, and a clinically relevant weight gain of ≥ 7% occurred in 8.0% of patients.

CONCLUSION

Paliperidone ER flexibly-dosed over 6 months was well tolerated and associated with a meaningful clinical response in patients with nonacute schizophrenia who had previously been unsuccessfully treated with oral olanzapine.

Discovery of pyrazolopyrimidine phosphodiesterase 10A inhibitors for the treatment of schizophrenia

Herein, we present the identification of a novel class of pyrazolopyrimidine phosphodiesterase 10A (PDE10A) inhibitors. Beginning with a lead molecule (1) identified through a fragment-based drug discovery (FBDD) effort, lead optimization was enabled by rational design, X-ray crystallography, metabolic and off-target profiling, and fragment scaffold-hopping. We highlight the discovery of PyP-1, a potent, highly selective, and orally bioavailable pyrazolopyrimidine inhibitor of PDE10A. PyP-1 exhibits sub-nanomolar potency (PDE10A Ki=0.23nM), excellent pharmacokinetic (PK) and physicochemical properties, and a clean off-target profile. It displays dose-dependent efficacy in numerous pharmacodynamic (PD) assays that measure potential for anti-psychotic activity and cognitive improvement. PyP-1 also has a clean preclinical profile with respect to cataleptic potential in rats, prolactin secretion, and weight gain, common adverse events associated with currently marketed therapeutics. Further, PyP-1 displays in vivo preclinical target engagement as measured by PET enzyme occupancy in concert with [(11)C]MK-8193, a novel PDE10A PET tracer.

Social and clinical descriptors of antipsychotic prescription

OBJECTIVE

To identify descriptors of Antipsychotic (AP) prescription, focusing on second generation antipsychotics (SGAs), polypharmacy, and long-acting injections (LAIs).

METHODS

Outpatients of the Bologna-Community-Mental-Health-Centres with at least one AP prescription were selected. Patients' characteristics, service utilization, and AP prescriptions were collected from administrative databases. Prescriptions were grouped by class (SGA vs. First Generation Antipsychotics), drug combination (polypharmacy vs. monotherapy), and preparation (LAIs vs. regular administration). Multi-variate analyses were performed to identify prescription descriptors among socio-demographic and clinical variables.

RESULTS

Among 6,074 patients and 41,121 AP prescriptions, SGAs were used in 70.7% of subjects, AP polypharmacy in 25.3%, and LAIs in 17.5%. SGAs were prescribed more often for young, Italian patients, with higher education, voluntary hospitalization, and high number of visits. Descriptors of AP polypharmacy were: high number of visits and hospitalization, length of treatment, non-urban residency, male gender, unemployment. Characteristics associated to LAI prescription were: long duration of treatment, high number of visits, compulsory admissions, non-Italian nationality, male gender, age > 34, low education, unmarried status.

CONCLUSIONS

Besides illness severity, this study identified different socio-demographic descriptors of AP choices, raising concerns on the equity of treatments. Efforts should be directed to investigate appropriateness of AP treatments especially in social disadvantaged populations.

The risks and benefits of switching patients with schizophrenia or schizoaffective disorder from two to one antipsychotic medication: a randomized controlled trial

BACKGROUND

Despite little evidence to support its use and practice guidelines discouraging the practice, antipsychotic polypharmacy is widely prevalent in schizophrenia. This randomized controlled trial studied the effects of switching patients stable on two antipsychotic medications to one antipsychotic medication.

METHOD

104 adult outpatients with schizophrenia from 7 community mental health centers clinically stable on concurrent treatment with 2 antipsychotics were randomly assigned to stay on polypharmacy or to switch to antipsychotic monotherapy. Participants were followed for 1-year with assessments of symptoms and side effects occurring every 60days (7 total assessments). We examined differences in time trajectories in symptoms (PANSS, CGI) and side effects (EPS, metabolic, other) as a function of group assignment (switch vs. stay) and time, using intention-to-treat analysis.

RESULTS

Participants who switched to antipsychotic monotherapy experienced greater increases in symptoms than stay patients. These differences emerged in the second 6months of the trial. All-cause discontinuation rates over the 1-year trial were higher in the switch-to-monotherapy group than in the stay-on-polypharmacy group (42% vs. 13%; p<0.01). There were no differences in change over time in any of the side effect measures, except that stay patients experienced a greater decrease in Simpson Angus total scores than switch patients.

CONCLUSION

Clinicians should be cautious in switching patients with chronic schizophrenia who are stable on 2 antipsychotics to one antipsychotic. Given the challenges in discontinuing antipsychotic polypharmacy, adequate trials of evidence-based treatments such as clozapine and long-acting injectable antipsychotics should be undertaken in inadequately responsive schizophrenia patients before moving to antipsychotic polypharmacy.

[Maintenance Treatment With Antipsychotics for Adult Patients Diagnosed With Schizophrenia]

OBJECTIVES

To determine the effectiveness and security of the antipsychotics available for the management of adult patients with schizophrenia in the maintenance phase. To develop recommendations of treatment for the maintenance phase of the disease.

METHODS

A clinical practice guideline was elaborated under the parameters of the Methodological Guide of the Ministerio de Salud y Protección Social to identify, synthesize and evaluate the evidence and make recommendations about the treatment and follow-up of adult patients with schizophrenia. The evidence of NICE guide 82 was adopted and updated. The evidence was presented to the Guideline Developing Group and recommendations, employing the GRADE system, were produced.

RESULTS

18 studies were included to evaluate the effectiveness and / or safety of different antipsychotic drugs first and second generation. Overall, antipsychotics (AP) showed superiority over placebo in relapse rate over 12 months (RR 0.59 95% CI 0.42, 0.82) and hospitalization rate over 24 months of follow-up (RR 0.38 95% 0.27, 0.55); its use is associated with increased risk of treatment dropout (RR 0.53 95% CI 0.46, 0.61) and adverse events such as weight gain, dystonia, extrapyramidal symptoms and sedation. There was no difference in the outcome of re hospitalizations, comparisons on quality of life, negative symptoms or weight gain between AP first and second generation. Continuous or standard dose regimens appear to be superior to intermittent or low doses in reducing the risk of abandonment of treatment regimes.

CONCLUSION

Adult patients diagnosed with schizophrenia should receive maintenance treatment with antipsychotics. The medication of choice will depend on the management of the acute phase, the patient's tolerance to it and the presentation of adverse events.

The PDE10A inhibitor MP-10 and haloperidol produce distinct gene expression profiles in the striatum and influence cataleptic behavior in rodents

Phosphodiesterase 10A (PDE10A) has garnered attention as a potential therapeutic target for schizophrenia due to its prominent striatal expression and ability to modulate striatal signaling. The present study used the selective PDE10A inhibitor MP-10 and the dopamine D2 antagonist haloperidol to compare effects of PDE10A inhibition and dopamine D2 blockade on striatopallidal (D2) and striatonigral (D1) pathway activation. Our studies confirmed that administration of MP-10 significantly elevates expression of the immediate early genes (IEG) c-fos, egr-1, and arc in rat striatum. Furthermore, we demonstrated that MP-10 induced egr-1 expression was distributed evenly between enkephalin-containing D2-neurons and substance P-containing D1-neurons. In contrast, haloperidol (3 mg/kg) selectively activated egr-1 expression in enkephalin neurons. Co-administration of MP-10 and haloperidol (0.5 mg/kg) increased IEG expression to a greater extent than either compound alone. Similarly, in a rat catalepsy assay, administration of haloperidol (0.5 mg/kg) or MP-10 (3-30 mg/kg) did not produce cataleptic behavior when dosed alone, but co-administration of haloperidol with MP-10 (3 and 10 mg/kg) induced cataleptic behaviors. Interestingly, co-administration of haloperidol with a high dose of MP-10 (30 mg/kg) failed to produce cataleptic behavior. These findings are important for understanding the neural circuits involved in catalepsy and suggest that the behavioral effects produced by PDE10A inhibitors may be influenced by concomitant medication and the level of PDE10A inhibition achieved by the dose of the inhibitor.

Antipsychotic Use Pattern in People with Psychotic Disorder Living in Board and Care Facilities

INTRODUCTION

The aim of this survey is to determine the pattern of antipsychotic drug use in patients with psychotic disorders, living in board and care facilities and to investigate the related factors.

METHODS

We evaluated the antipsychotic drug use pattern in outpatients with psychotic disorders according to DSM-IV, living in board and care facilities. Patients using polypharmacy at least one month were compared with patients using monotherapy in terms of clinical and demographic characteristics.

RESULTS

Antipsychotic polypharmacy (with two: 34%, with more than two: 28%) was identified in 62% of the patients. The most frequently prescribed combination was olanzapine+quetiapine (13%), the rate of first and second generation combination was 50%, the rate of second generation antipsychotic combination was 44%, and the rate of first generation anytipsychotic combination was 4% in the two antipsychotic drug combination group. The rate of clozapine use was 3%. Use of polypharmacy was associated with the diagnosis of schizophrenia and schizoaffective disorder, young age, suicidal behavior, multiple hospitalizations, clinical severity, and the need of anticholinergic drug.

CONCLUSION

The ratio of using more than two antipsychotic drug combination is high (28%) in psychotic patients living in board and care, and rate of clozapine use is low, which shows that clinical practice is inconsistent with the treatment guidelines recommendations. It appears that further education to rationale antipsychotic drug use in psychiatric practices is required.

Analysis of drugs in plasma samples from schizophrenic patients by column-switching liquid chromatography-tandem mass spectrometry with organic-inorganic hybrid cyanopropyl monolithic column

This study reports on the development of a rapid, selective, and sensitive column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyze sixteen drugs (antidepressants, anticonvulsants, anxiolytics, and antipsychotics) in plasma samples from schizophrenic patients. The developed organic-inorganic hybrid monolithic column with cyanopropyl groups was used for the first dimension of the column-switching arrangement. This arrangement enabled online pre-concentration of the drugs (monolithic column) and their subsequent analytical separation on an XSelect SCH C18 column. The drugs were detected on a triple quadrupole tandem mass spectrometer (multiple reactions monitoring mode) with an electrospray ionization source in the positive ion mode. The developed method afforded adequate linearity for the sixteen target drugs; the coefficients of determination (R(2)) lay above 0.9932, the interassay precision had coefficients of variation lower than 6.5%, and the relative standard error values of the accuracy ranged from -14.0 to 11.8%. The lower limits of quantification in plasma samples ranged from 63 to 1250pgmL(-1). The developed method successfully analyzed the target drugs in plasma samples from schizophrenic patients for therapeutic drug monitoring (TDM).

Antipsychotic patterns of use in patients with schizophrenia: polypharmacy versus monotherapy

BACKGROUND

The objective of this study was to characterize real-world treatment patterns in the prescription of antipsychotic polypharmacy (≥ 2 concurrent antipsychotics) compared with antipsychotic monotherapy for patients with schizophrenia.

METHODS

This study was a retrospective claims-based analysis of patients (aged 13-64 years) with schizophrenia belonging to an employer-based health plan. Duration of therapy was measured as the number of treatment days over one year following the initial date of antipsychotic therapy. Discontinuation was defined as a 90-day gap in antipsychotic treatment (or in at least one antipsychotic for the polypharmacy group). Logistic regression analyses were used to predict discontinuation within one year. Ordinary Least Squares (OLS) regressions were used to predict duration of therapy (by type of therapy) when controlling for gender, region, number of somatic and psychiatric comorbidities, Deyo-Charlson comorbidity score, and number of psychiatric and somatic medications.

RESULTS

Of the 4,156 patients, 3,188 received monotherapy and 968 received polypharmacy. Mean age was 40 years (37.8 years for polypharmacy vs 40.3 years for monotherapy, p < 0.001). Within one year, 77% of the polypharmacy group and 54% of the monotherapy group discontinued treatment. The average duration of therapy was 163 [SD = 143] days in the polypharmacy group vs 253 [SD = 147] days in the monotherapy group. In both cohorts, patients <25 years had a higher frequency of discontinuations than those ≥ 26 years. Age and polypharmacy were independent predictors of treatment duration and discontinuation prior to one year.

CONCLUSIONS

One quarter of patients with schizophrenia received antipsychotic polypharmacy. Discontinuation was higher in the polypharmacy group. Age and polypharmacy were significant predictors of treatment discontinuation.

Antipsychotic use in children and adolescents: a 1-year follow-up study

OBJECTIVE

The objective of this study was to analyze the initial treatment with antipsychotics (APs) and its changes during the first year of treatment in patients visited in specialized child and adolescent psychiatry departments.

METHODS

Participants were 265 patients, aged 4 to 17 years, who attended consecutively at 4 different centers and were naive of AP or quasi-naive (less than 30 days since the beginning of AP treatment). Type of AP, dosage, and concomitant medication were registered at baseline, 1, 3, 6, and 12 months after beginning the treatment with AP.

RESULTS

At baseline, the patients' mean age was 14.4 (2.9) years, and 145 (54.7%) patients were males. Antipsychotics were more prescribed in the following: schizophrenia spectrum disorders (30.2%), disruptive behavior disorders (DBDs) (18.9%), bipolar disorders (14.3%), depressive disorders (12.8%), and eating disorders (11.7%). A total of 93.2% of the patients were on an off-label indication of AP. Risperidone was the AP most prescribed in all the assessments, but differences were observed in the type of AP according to diagnosis. Thus, risperidone was significantly most prescribed in patients with DBD and olanzapine was most prescribed in patients with eating disorders. Olanzapine and quetiapine were the second-generation APs (SGAs) most prescribed after risperidone, and haloperidol was the most prescribed first-generation AP. Up to 8.3% of patients during the follow-up were on AP polypharmacy. Almost 16% patients had a change in its AP treatment during the follow-up, and the main switch was from one SGA to another.

CONCLUSIONS

Second-generation APs were the APs most prescribed in our sample and approximately 93% of the patients used AP off-label. Risperidone was the most common AP used above all in patients with DBD, whereas olanzapine was most prescribed in patients with eating disorders. Antipsychotic polypharmacy and switch rates were low during the follow-up.

Critical review of antipsychotic polypharmacy in the treatment of schizophrenia

Antipsychotic polypharmacy remains prevalent; it has probably increased for the treatment of schizophrenia in real-world clinical settings. The current evidence suggests some clinical benefits of antipsychotic polypharmacy, such as better symptom control with clozapine plus another antipsychotic, and a reversal of metabolic side-effects with a concomitant use of aripiprazole. On the other hand, the interpretation of findings in the literature should be made conservatively in light of the paucity of good studies and potentially serious side-effects. Also, although the available data are still limited, two smaller-scale clinical trials provide preliminary evidence that converting antipsychotic polypharmacy to monotherapy could be a valid and reasonable treatment option. Several studies have explored strategies to change physicians' antipsychotic polypharmacy prescribing behaviours. These have revealed that, while the impact of purely educational interventions may be limited, more aggressive procedures such as directly notifying physicians by letters or phone calls can be more effective in reducing antipsychotic polypharmacy. In conclusion, antipsychotic polypharmacy can work for some clinically difficult conditions; however, it should be the exception rather than the rule and may be avoidable in many patients. More importantly, the paucity of the data clearly emphasizes the need for further investigations on not only advantages and disadvantages of antipsychotic polypharmacy, but also regarding effective interventions in already prescribed polypharmacy regimens.

Efficacy and clinical determinants of antipsychotic polypharmacy in psychotic patients experiencing an acute relapse and admitted to hospital stay: results from a cross-sectional and a subsequent longitudinal pilot study

Background. Antipsychotic polypharmacy is used in several psychiatric disorders, despite poor evidence existing to support this practice. Aim. We evaluated whether psychotic patients in acute relapse exposed to antipsychotic polypharmacy (AP + AP) showed different demographic, clinical, or psychopathological features compared to those exposed to one antipsychotic (AP) and whether AP + AP patients showed significantly higher improvement compared to AP patients after a 4-week treatment. Methods. Inpatients were subdivided into AP + AP and AP ones. In the cross-sectional step, patients were compared according to demographics, clinical variables, and scores on rating scales. In the longitudinal step, patients remained for 4 weeks under admission medications and were compared for clinical improvement. Results. AP + AP patients were more frequently diagnosed with schizophrenia and mental retardation as a comorbid illness. AP + AP patients were more frequently under first-generation antipsychotics and had worse clinical presentation. After 4 weeks of treatment, both AP + AP and AP patients improved compared to the baseline. However, AP patients scored significantly less than AP + AP patients at the Clinical Global Impression Scale at the 4-week time point but not at the baseline, indicating a treatment-specific improvement. Conclusions. Antipsychotic polypharmacy may be offered to specific types of psychotic patients. However, efficacy of this strategy is limited at best.

Genetic deletion and pharmacological inhibition of phosphodiesterase 10A protects mice from diet-induced obesity and insulin resistance

Phosphodiesterase 10A (PDE10A) is a novel therapeutic target for the treatment of schizophrenia. Here we report a novel role of PDE10A in the regulation of caloric intake and energy homeostasis. PDE10A-deficient mice are resistant to diet-induced obesity (DIO) and associated metabolic disturbances. Inhibition of weight gain is due to hypophagia after mice are fed a highly palatable diet rich in fats and sugar but not a standard diet. PDE10A deficiency produces a decrease in caloric intake without affecting meal frequency, daytime versus nighttime feeding behavior, or locomotor activity. We tested THPP-6, a small molecule PDE10A inhibitor, in DIO mice. THPP-6 treatment resulted in decreased food intake, body weight loss, and reduced adiposity at doses that produced antipsychotic efficacy in behavioral models. We show that PDE10A inhibition increased whole-body energy expenditure in DIO mice fed a Western-style diet, achieving weight loss and reducing adiposity beyond the extent seen with food restriction alone. Therefore, chronic THPP-6 treatment conferred improved insulin sensitivity and reversed hyperinsulinemia. These data demonstrate that PDE10A inhibition represents a novel antipsychotic target that may have additional metabolic benefits over current medications for schizophrenia by suppressing food intake, alleviating weight gain, and reducing the risk for the development of diabetes.

The Influence of Previous Antipsychotic Polypharmacy Versus Monotherapy on the Effectiveness of Antipsychotic after Switching to Paliperidone Extended-release

OBJECTIVE

Although antipsychotic polypharmacy is widely used in the pharmacotherapy of schizophrenia, its effectiveness is controversial. In particular, clinicians tend to avoid switching to monotherapy in patients who have been prescribed polypharmacy. In the present study, the authors investigate whether there is difference in time to discontinuation of antipsychotics between patients on previous monotherapy or polypharmacy.

METHODS

Pooled analysis was conducted on two 24-week, multicenter, open-label, non-comparative studies that were originally designed to investigate the effectiveness of switching to paliperidone extended-release (ER) in patients with schizophrenia. Patients were divided into two groups according to previously prescribed antipsychotics, that is, to a polypharmacy group or a monotherapy group. The primary outcome measure was time to discontinuation of paliperidone ER. In addition, the authors sought to identify clinical variables that influence time to discontinuation.

RESULTS

Before switching to paliperidone ER, 535 of 673 (79.5%) patients were prescribed antipsychotic monotherapy, and the remaining 138 (20.5%) patients were prescribed antipsychotic polypharmacy. No significant differences in time to discontinuation of paliperidone ER were observed between the polypharmacy and monotherapy groups. Personal and social performance scale score was the only factor found to influence time to discontinuation of paliperidone ER. No differences in psychopathology or adverse effects were found between the monotherapy and polypharmacy groups.

CONCLUSION

Our results suggest that number of antipsychotics prescribed before switching to monotherapy does not influence clinical prognosis in patients with schizophrenia.

Interventions to reduce antipsychotic polypharmacy: a systematic review

BACKGROUND

It still remains unclear as to how to counteract antipsychotic polypharmacy that remains controversial but common. The objective of this study was to synthesize the clinical evidence to reduce antipsychotic polypharmacy (i.e. use of multiple antipsychotics) in schizophrenia.

METHODS

A literature search was performed to identify clinical trials that attempted to reduce antipsychotic polypharmacy in patients with schizophrenia by any form of systematic intervention using PubMed as well as MEDLINE, EMBASE, and PsycINFO (last search: June 2012). The search terms included "antipsychotics" and "polypharmacy". Cross-referencing was also performed.

RESULTS

The literature search identified 17 studies. Only 3 studies (1 randomized controlled trial and 2 open-label trials) were found that systematically switched antipsychotic polypharmacy to monotherapy. In two of them, more than two thirds of the subjects successfully completed the switch (40/58, 69.0%; 34/44, and 77.3%, respectively) while less than half the subjects tolerated it in the other study (6/14 and 42.9%) although the sample size was very small. On the other hand, 14 studies that examined impacts of interventions have physicians refrain from antipsychotic polypharmacy. While a modest intervention with educational approach alone was effective in three of the five articles, a more assertive intervention that directly cautioned physicians on the use of polypharmacy was effective in 10 of 12 articles.

CONCLUSION

The literature search revealed the paucity of the data. Careful switching from polypharmacy to monotherapy seems feasible in a majority of patients with schizophrenia. Assertive interventions, rather than passive educational approaches alone, appear more effective in reducing antipsychotic polypharmacy.

Dental conditions in inpatients with schizophrenia: a large-scale multi-site survey

BACKGROUND

Clinical relevance of dental caries is often underestimated in patients with schizophrenia. The objective of this study was to examine dental caries and to identify clinical and demographic variables associated with poor dental condition in patients with schizophrenia.

METHODS

Inpatients with schizophrenia received a visual oral examination of their dental caries, using the decayed-missing-filled teeth (DMFT) index. This study was conducted in multiple sites in Japan, between October and December, 2010. A univariate general linear model was used to examine the effects of the following variables on the DMFT score: age, sex, smoking status, daily intake of sweets, dry mouth, frequency of daily tooth brushing, tremor, the Clinical Global Impression-Schizophrenia Overall severity score, and the Cumulative Illness Rating Scale for Geriatrics score.

RESULTS

523 patients were included in this study (mean ± SD age = 55.6 ± 13.4 years; 297 men). A univariate general linear model showed significant effects of age group, smoking, frequency of daily tooth brushing, and tremor (all p's < 0.001) on the DMFT score (Corrected Model: F(23, 483) = 3.55, p < 0.001, R2 = 0.42) . In other words, older age, smoking, tremor burden, and less frequent tooth brushing were associated with a greater DMFT score.

CONCLUSIONS

Given that poor dental condition has been related with an increased risk of physical co-morbidities, physicians should be aware of patients' dental status, especially for aged smoking patients with schizophrenia. Furthermore, for schizophrenia patients who do not regularly brush their teeth or who exhibit tremor, it may be advisable for caregivers to encourage and help them to perform tooth brushing more frequently.

Discovery of tetrahydropyridopyrimidine phosphodiesterase 10A inhibitors for the treatment of schizophrenia

We describe the discovery of potent and orally bioavailable tetrahydropyridopyrimidine inhibitors of phosphodiesterase 10A by systematic optimization of a novel HTS lead. Lead compound THPP-1 exhibits nanomolar potencies, excellent pharmacokinetic properties, and a clean off-target profile. It displays in vivo target engagement as measured by increased rat striatal cGMP levels upon oral dosing. It shows dose-dependent efficacy in a key pharmacodynamic assay predictive of antipsychotic activity, the psychostimulant-induced rat hyperlocomotion assay. Further, THPP-1 displays significantly fewer preclinical adverse events in assays measuring prolactin secretion, catalepsy, and weight gain, in contrast to the typical and atypical antipsychotics haloperidol and olanzapine.

The novel phosphodiesterase 10A inhibitor THPP-1 has antipsychotic-like effects in rat and improves cognition in rat and rhesus monkey

Phosphodiesterase 10A (PDE10A) is a novel target for the treatment of schizophrenia that may address multiple symptomatic domains associated with this disorder. PDE10A is highly expressed in the brain and functions to metabolically inactivate the important second messengers cAMP and cGMP. Here we describe effects of a potent and orally bioavailable PDE10A inhibitor [2-(6-chloropyridin-3-yl)-4-(2-methoxyethoxy)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl](imidazo[1,5-a]pyridin-1-yl)methanone] (THPP-1) on striatal signaling pathways, in behavioral tests that predict antipsychotic potential, and assays that measure episodic-like memory in rat and executive function in rhesus monkey. THPP-1 exhibits nanomolar potency on the PDE10A enzyme, demonstrates excellent pharmacokinetic properties in multiple preclinical animal species, and is selective for PDE10A over other PDE families of enzymes. THPP-1 significantly increased phosphorylation of proteins in the striatum involved in synaptic plasticity, including the a-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid receptor (AMPA) GluR1 subunit, extracellular receptor kinase (ERK), and cAMP-response element binding protein (CREB). THPP-1 produced dose-dependent effects in preclinical assays predictive of antipsychotic activity including attenuation of MK-801-induced psychomotor activation and condition avoidance responding in rats. At similar plasma exposures, THPP-1 significantly increased object recognition memory in rat and attenuated a ketamine-induced deficit in the object retrieval detour task in rhesus monkey. These findings suggest that PDE10A inhibitors have the potential to impact multiple symptomatic domains of schizophrenia including positive symptoms and cognitive impairment. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

Predictors of antipsychotic monotherapy with olanzapine during a 1-year naturalistic study of schizophrenia patients in Japan

PURPOSE

Although expert guidelines for the treatment of schizophrenia recommend antipsychotic monotherapy, the use of antipsychotic polypharmacy is common. This study identified characteristics that differentiate patients with schizophrenia who are treated with olanzapine monotherapy versus polypharmacy in usual care in Japan.

PATIENTS AND METHODS

In a large (N = 1850) prospective, observational study, Japanese patients with schizophrenia who initiated treatment with olanzapine were followed for 1 year. Consistent with past research, antipsychotic polypharmacy was defined as the concurrent use of olanzapine and another antipsychotic for at least 60 days. Switching was defined as discontinuing a prior antipsychotic therapy rather than augmenting the medication regimen. Predictors of antipsychotic monotherapy were based on information available at the time of olanzapine initiation. Baseline characteristics were compared using t-tests and χ(2) tests. Stepwise logistic regression was used to identify independent predictors of monotherapy.

RESULTS

Patients treated with olanzapine monotherapy (43.2%) differed from those treated with antipsychotic polypharmacy (56.8%) on demographics, treatment history, baseline symptom levels, functional levels, and treatment-emergent adverse events. Stepwise logistic regression identified multiple variables that significantly predicted monotherapy: older age, shorter duration of schizophrenia, outpatient status, comorbid medical conditions, lower body mass index, no prior anticholinergic use, no prior mood stabilizer use, and switching from a previous antipsychotic (typical or atypical).

CONCLUSION

Consistent with prior research in Japan, antipsychotic polypharmacy appears to be common in the treatment of schizophrenia. Patients treated with monotherapy could be differentiated from those treated with antipsychotic polypharmacy based on a specific set of demographic and baseline clinical characteristics.

Comparison of patients undergoing switching versus augmentation of antipsychotic medications during treatment for schizophrenia

It is often difficult to determine whether a patient may best benefit by augmenting their current medication or switching them to another. This post-hoc analysis compares patients' clinical and functional profiles at the time their antipsychotic medications were either switched or augmented. Adult outpatients receiving oral antipsychotic treatment for schizophrenia were assessed during a 12-month international observational study. Clinical and functional measures were assessed at the time of first treatment switch/augmentation (0-14 days prior) and compared between Switched and Augmented patient groups. Due to low numbers of patients providing such data, interpretations are based on effect sizes. Data at the time of change were available for 87 patients: 53 Switched and 34 Augmented. Inadequate response was the primary reason for treatment change in both groups, whereas lack of adherence was more prevalent in the Switched group (26.4% vs 8.8%). Changes in clinical severity from study initiation to medication change were similar, as indicated by Clinical Global Impressions-Severity scores. However, physical and mental component scores of the 12-item Short-Form Health Survey improved in the Augmented group, but worsened in the Switched group. These findings suggest that the patient's worsening or lack of meaningful improvement prompts clinicians to switch antipsychotic medications, whereas when patients show some improvement, clinicians may be more likely to try bolstering the improvements through augmentation. Current findings are consistent with physicians' stated reasons for switching versus augmenting antipsychotics in the treatment of schizophrenia. Confirmation of these findings requires further research.