Health economics study of paliperidone palmitate in the treatment of schizophrenia: a 12-month cohort study.

BACKGROUND: To analyze the economic benefits of paliperidone palmitate in the treatment of schizophrenia. METHODS: We collected 546 patients who met the diagnostic criteria for schizophrenia according to the 《International Statistical Classification of Diseases and Related Health Problems,10th》(ICD-10). We gathered general population data such as gender, age, marital status, and education level, then initiated treatment with paliperidone palmitate. Then Follow-up evaluations were conducted at 1, 3, 6, 9, and 12 months after the start of treatment to assess clinical efficacy, adverse reactions, and injection doses. We also collected information on the economic burden before and after 12 months of treatment, as well as the number of outpatient visits and hospitalizations in the past year to analyze economic benefits. RESULTS: The baseline patients totaled 546, with 239 still receiving treatment with paliperidone palmitate 12 months later. After 12 months of treatment, the number of outpatient visits per year increased compared to before (4 (2,10) vs. 12 (4,12), Z=-5.949, P < 0.001), while the number of hospitalizations decreased (1 (1,3) vs. 1 (1,2), Z = 5.625, P < 0.001). The inpatient costs in the direct medical expenses of patients after 12 months of treatment decreased compared to before (5000(2000,12000) vs. 3000 (1000,8050), P < 0.05), while there was no significant change in outpatient expenses and direct non-medical expenses (transportation, accommodation, meal, and family accompanying expenses, etc.) (P > 0.05); the indirect costs of patients after 12 months of treatment (lost productivity costs for patients and families, economic costs due to destructive behavior, costs of seeking non-medical assistance) decreased compared to before (300(150,600) vs. 150(100,200), P < 0.05). CONCLUSION: Palmatine palmitate reduces the number of hospitalizations for patients, as well as their direct and indirect economic burdens, and has good economic benefits.

Effects of electroacupuncture combined with paliperidone palmitate long-acting injection on withdrawal symptoms and neurotransmitters in methamphetamine addicts.

OBJECTIVE: To investigate the effects of electroacupuncture combined with paliperidone palmitate long-acting injection (PP-LAI) on withdrawal symptoms and neurotransmitters in methamphetamine (MA) addicts. MATERIALS AND METHODS: A total of 109 methamphetamine addicts, who were treated in the hospital from October 2021 to October 2022, were selected. According to the random number table, the patients were divided into the study group (n=54) and the control group (n=55), in which the control group was treated with PP-LAI and the study group was treated with electroacupuncture on the basis of the control group; the methamphetamine withdrawal symptom score scale was used to assess the therapeutic effect before treatment and within 12 months after treatment; the changes of brain neurotransmitters dopamine, γ-aminobutyric acid, serotonin, acetylcholine values were compared between the two groups. RESULTS: 1) There was no statistical difference in MA withdrawal symptom scores between the two groups before treatment (p>0.05); 2) MA withdrawal symptom scores have a statistically significant difference between the study group and the control group after 3 and 6 months of treatment; 3) dopamine levels in the study group were significantly higher than those in the control group after 6 months of completion of treatment, and γ-aminobutyric acid values and 5- serotonin values in the study group were significantly lower than those in the control group (p<0.05). CONCLUSIONS: Electroacupuncture combined with PP-LAI can partially improve the withdrawal symptoms and anxiety of methamphetamine addicts. This is a potential treatment for preventing relapse of withdrawal symptoms.

Model-Informed Clinical Development of Once-Every-6-Month Injection of Paliperidone Palmitate in Patients with Schizophrenia: A Pharmacometric Bridging Approach (Part I).

BACKGROUND AND OBJECTIVE: A model-informed drug development (MIDD) approach was implemented for paliperidone palmitate (PP) 6-month (PP6M) clinical development, using pharmacokinetics and pharmacokinetic/pharmacodynamic model-based simulations. METHODS: PP6M pharmacokinetics were simulated by extending the PP 3-month (PP3M) pharmacokinetic model to account for increased injection volume, and hence dose. Contribution of the MIDD approach to the design of the pivotal PP6M phase-3 study (PP6M/PP3M noninferiority study, NCT03345342) investigating schizophrenia relapse rates was twofold: (1) PP6M dose selection, and (2) hypothesis generation that lower trough concentrations (Ctrough) associated with PP6M, relative to PP3M, were not associated with lower efficacy, which was to be evaluated in the phase-3 study. Moreover, accompanied by an intense sampling scheme to adequately characterize paliperidone pharmacokinetics and to elucidate the potential relationship between concentration and safety/efficacy, the bridging strategy eliminated the need for additional phase-1/phase-2 clinical studies. RESULTS: Using a MIDD bridging strategy, PP6M doses were selected that, compared with PP3M, were expected to have a similar range of exposures and a noninferior relapse rate and safety profile. Clinical data from PP6M/PP3M noninferiority study confirmed that PP6M, compared with PP3M, had a similar range of exposures (T'jollyn et al. in Eur J Drug Metab Pharmacokinet 2024), as well as a noninferior relapse rate and safety profile (this manuscript). CONCLUSIONS: Consistency of the MIDD approach with observed clinical outcomes confirmed the hypothesis that lower Ctrough did not lead to increased relapse rates at the doses administered. Although higher paliperidone peak concentrations are achieved with corresponding doses of PP6M relative to PP3M in the phase-3 clinical study, types and incidences of treatment-related adverse events were comparable between PP6M and PP3M groups and no new safety concerns emerged for PP6M (Najarian et al. in Int J Neuropsychopharmacol 25(3):238-251, 2022).

Model-Informed Clinical Development of 6-Monthly Injection of Paliperidone Palmitate in Patients with Schizophrenia: Dosing Strategies Guided by Population Pharmacokinetic Modeling and Simulation (Part II).

BACKGROUND AND OBJECTIVE: Paliperidone palmitate 6-month (PP6M) intramuscular (IM) injection is the longest-acting treatment available for patients with schizophrenia. A population pharmacokinetic (popPK) modeling and simulation approach was deployed to inform dosing strategies for PP6M. METHODS: The extensive analysis database included 15,932 paliperidone samples from 700 patients receiving gluteal paliperidone palmitate 3-month (PP3M) or PP6M injections in the double-blind phase of a phase-3 noninferiority study (NCT03345342). Exposure parameters for paliperidone appeared to increase dose-proportionally within each dosing schedule (PP3M/PP6M). The range of paliperidone exposures after IM administration of PP6M overlaps with that of corresponding doses of oral paliperidone extended release, PP 1-month (PP1M), and PP3M. Model-based simulations were performed to investigate paliperidone exposures in different PP6M dosing scenarios and relevant subpopulations. RESULTS: A dosing window of ≤ 2 weeks earlier and ≤ 3 weeks later than the target 6-month interval for maintenance treatment with PP6M dosing maintains paliperidone exposures at levels that are not expected to substantially impact its safety and efficacy. For missed-dose scenarios, tailored re-initiation regimens are proposed that should be applied before resuming PP6M maintenance dosing. Regarding subpopulations, PP6M 700 mg eq. is the highest dose recommended in mild renal-impairment patients; the paliperidone pharmacokinetics after PP6M administration is not affected by sex, body mass index, or age in a clinically meaningful way. CONCLUSION: Paliperidone concentration-time profiles after PP6M and PP3M dosing were adequately described by the popPK model. Model-based simulation results provide guidance for clinicians on initiating PP6M therapy, transitioning between paliperidone formulations, the dosing windows to use for maintenance dosing, and managing missed PP6M doses.

Switching from paliperidone palmitate 3-monthly long-acting injection to oral aripiprazole in a pregnant woman with schizophrenia: a case report and short review.

Treatment with long-acting injection (LAI) antipsychotics, such as paliperidone palmitate, has improved the quality of life in terms of symptoms and prevention of relapses in patients with schizophrenia. Although there are plenty of evidences about the efficacy and safety of paliperidone palmitate 3-monthly injection (PP3M) in adults with schizophrenia, literature appears lacking about the use of LAIs during pregnancy. We hereby describe the clinical case of a pregnant woman affected by schizophrenia (DSM-5-TR), taking pharmacological treatment of PP3M. Considering the inadequate evidence regarding the use of PP3M in pregnancy in agreement with the patient, we switched PP3M to an oral therapy with aripiprazole. The switch to oral aripiprazole allowed the patient to improve her sense of autonomy and strengthen the therapeutic relationship. To our knowledge, this is the first case report monitoring an entire pregnancy of a women affected by schizophrenia in treatment with PP3M injection and oral aripiprazole. No obstetrical or fetal complications were reported. As the research in this field is very demanding, it would be precipitous to derive final conclusions from the current case report, but we hope to build a growing number of data that would allow us to make more appropriate and safe therapeutic choices in such a vulnerable phase as the peripartum.

Risk of Cardiovascular Events in Schizophrenic Patients Treated with Paliperidone Palmitate Once-Monthly Injection (PP1M): A Population-Based Retrospective Cohort Study in Taiwan.

BACKGROUND: Schizophrenia is one of the leading causes of disability. Paliperidone palmitate once-monthly injection (PP1M) was developed to provide consistent drug delivery and improve medication adherence for maintenance treatment. It is well known that patients with schizophrenia have higher cardiovascular risks, however little is known about the cardiovascular risks of patients with schizophrenia treated with PP1M in Asia. OBJECTIVE: This study aimed to estimate the incidence of cardiovascular events after initiating PP1M treatment and evaluate the cardiovascular risk associations compared with oral second-generation antipsychotics (SGAs). METHODS: Data from Taiwan's National Health Insurance Research Database were used to identify a cohort of adult patients with schizophrenia who received any SGAs from 1 March 2012 to 31 December 2018. Patients who initiated PP1M treatment were enrolled for descriptive analysis of incidence rates. PP1M patients were propensity matched 1:1 to patients initiating a new oral SGA, for comparative analysis based on demographics, clinical characteristics and treatment history at baseline, in three-step matching procedures, following the prevalent new-user design to enhance comparability. Follow-up ended at the end of the treatment episode of index drug, death, last record available, or end of the study (31 December 2019). Study endpoints included serious cardiovascular events (including severe ventricular arrhythmia and sudden death), expanded serious cardiovascular events (which further included acute myocardial infarction and ischemic stroke), and cardiovascular hospitalizations. Risks of study endpoints between matched cohorts were compared using Cox regression. RESULTS: Overall, 11,023 patients initiating PP1M treatment were identified (49.5% were females; mean age of 43.2 [12.2] years). Overall incidences for serious cardiovascular events, expanded serious cardiovascular events, and cardiovascular hospitalizations were 3.92, 7.88 and 51.96 per 1000 person-years, respectively. In matched cohort analysis (N = 10,115), the hazard ratios (HRs) between initiating PP1M and a new oral SGA for serious cardiovascular events, expanded serious cardiovascular events, and cardiovascular hospitalizations were 0.86 (95% confidence interval [CI] 0.55-1.36), 0.88 (95% CI 0.63-1.21), and 0.78 (95% CI 0.69-0.89), respectively. CONCLUSION: This study reported the population-based incidence of cardiovascular events in schizophrenic patients initiating PP1M treatment. PP1M was not associated with increased risks of serious cardiovascular events but was potentially associated with lower risks of cardiovascular hospitalizations compared with oral SGAs.

Dual Atypical Antipsychotics in Treatment-Resistant Schizophrenia: A Correctional Case Report and Review of Literature.

Treatment-resistant schizophrenia (TRS) is a challenging condition to treat for the correctional psychiatrist. Guidelines from the American Psychiatric Association indicate that the first-line pharmacotherapy for TRS is the use of the atypical antipsychotic clozapine. The use of clozapine is unique in that it requires patient adherence with weekly blood draws as a prophylactic measure against agranulocytosis and leukopenia. In the correctional setting, patients with severe and persistent schizophrenia are frequently nonadherent due to lack of insight and anemic access to health care resources, specifically as these pertain to clozapine. Therefore, an alternative treatment option would be a welcome solution for this demographic. Our literature review demonstrates a limited number of studies documenting the successful use of clozapine alternatives or combination antipsychotic therapy for treatment of TRS. In this article, we present a putative case where we believe that a combination regimen of paliperidone palmitate, oral aripiprazole, and escitalopram led to a notable mitigation of both positive and negative symptoms of psychosis in the case of an incarcerated patient with TRS, as well as an improvement in functional stability, which was conducive to housing in a less restrictive setting. A brief review of the published literature follows the report.

Development of a physiologically-based pharmacokinetic model to simulate the pharmacokinetics of intramuscular antiretroviral drugs.

There is growing interest in the use of long-acting (LA) injectable drugs to improve treatment adherence. However, their long elimination half-life complicates the conduct of clinical trials. Physiologically-based pharmacokinetic (PBPK) modeling is a mathematical tool that allows to simulate unknown clinical scenarios for LA formulations. Thus, this work aimed to develop and verify a mechanistic intramuscular PBPK model. The framework describing the release of a LA drug from the depot was developed by including both the physiology of the injection site and the physicochemical properties of the drug. The framework was coded in Matlab® 2020a and implemented in our existing PBPK model for the verification step using clinical data for LA cabotegravir, rilpivirine, and paliperidone. The model was considered verified when the simulations were within twofold of observed data. Furthermore, a local sensitivity analysis was conducted to assess the impact of various factors relevant for the drug release from the depot on pharmacokinetics. The PBPK model was successfully verified since all predictions were within twofold of observed clinical data. Peak concentration, area under the concentration-time curve, and trough concentration were sensitive to media viscosity, drug solubility, drug density, and diffusion layer thickness. Additionally, inflammation was shown to impact the drug release from the depot. The developed framework correctly described the release and the drug disposition of LA formulations upon intramuscular administration. It can be implemented in PBPK models to address pharmacological questions related to the use of LA formulations.

A comparison of recurrence rates after discontinuation of second-generation antipsychotic long-acting injectable versus corresponding oral antipsychotic in the maintenance treatment of bipolar disorder: A systematic review.

It has been previously reported that among patients with schizophrenia that long-acting injectable (LAI) antipsychotic formulations can delay time to relapse longer when compared to their oral equivalents when patients discontinue therapy. Unanswered is whether this same pattern would be observed for patients with bipolar disorder receiving maintenance treatment. A systematic review was undertaken to identify relevant studies of LAI antipsychotics in maintenance treatment of bipolar disorder, employing a placebo-controlled randomized withdrawal design, and where equivalent studies using the corresponding oral formulation were also available. We found five studies [one aripiprazole monohydrate once monthly (AOM) study, one oral aripiprazole (OARI) study, two 2 weeks risperidone-LAI (RIS-LAI) studies, and one oral paliperidone (OPAL) study]. Numerically lower recurrence rates at 2, 4, 6, 8, 12, 16, 20, and 26 weeks were observed when AOM was discontinued when compared with discontinuation from OARI. Numerically lower recurrence rates at 2, 4, 6, 8, and 16 weeks were observed when RIS-LAI was discontinued when compared with discontinuation from OPAL. These results can be interpreted as a substantial delay in time to recurrence with a LAI antipsychotics formulation compared to the oral equivalent when medication is discontinued in patients with mania who had been stabilized on LAI antipsychotics or corresponding oral antipsychotics.

Efficacy and safety of paliperidone palmitate 6-monthly long-acting injectable in reduction of relapses in patients with schizophrenia: An Asian subgroup analysis of phase 3, randomized study.

BACKGROUND: Evaluate efficacy and safety of paliperidone palmitate 6-monthly (PP6M) for patients with schizophrenia in the Asian subgroup of a global, multicenter, noninferiority phase-3 study (NCT03345342). METHODS: Patients received paliperidone palmitate 1-monthly (PP1M, 100/150 mg eq.) or paliperidone palmitate 3-monthly (PP3M, 350/525 mg eq.) during the maintenance phase and entered a 12-month double-blind (DB) phase, wherein they were randomized (2:1) to PP6M (700/1000 mg. eq.) or PP3M (350/525 mg eq.). Subgroup analysis was performed for 90 (12.7%) patients from Asia region (India, Taiwan, Malaysia, Hong Kong, and Korea). Primary endpoint was time-to-relapse during DB phase (Kaplan-Meier estimates). Secondary endpoints were changes from baseline in Positive and Negative Syndrome Scale, Clinical Global Impression-Severity scale, Personal and Social Performance (PSP) scale score. RESULTS: In Asian subgroup, 91.9% (82/90) of patients completed DB phase (PP6M: 54/62 [87%]; PP3M: 28/28 [100%]). Median time-to-relapse was "not-estimable" due to low relapse rates in both groups. Estimated difference (95% confidence interval [CI]) between relapse-free patients in PP6M and PP3M groups of Asian subgroup was -0.1% [-8.5%, 8.4%] (global study population: -2.9% [-6.8%, 1.1%]). Mean change from baseline in secondary efficacy parameters was comparable between both groups, similar to the global study population. The incidence of extrapyramidal symptoms was higher in the Asian subgroup than in the global study population. CONCLUSION: Consistent with the global study population, PP6M was noninferior to PP3M in preventing relapse in patients with schizophrenia from the Asia region. Findings suggest the possibility of switching from PP1M/PP3M to twice-yearly PP6M without loss of efficacy and with no unexpected safety concerns.

Incident infection during the first year of treatment - A comparison of clozapine and paliperidone palmitate long-acting injection.

BACKGROUND: To examine the risk of infection in patients prescribed clozapine compared with patients prescribed paliperidone palmitate long-acting injection (PPLAI). METHOD: A retrospective, 1-year, cohort study conducted on events occurring in eligible patients beginning treatment for the first time with clozapine or PPLAI between June 2017 and June 2019 in a UK mental health trust providing in-patient and out-patient services. RESULTS: The study included 64 patients starting clozapine and 120 patients starting PPLAI. Incidence of infection was greater in clozapine starters than in PPLAI starters (28% vs 6%; p = 0.001; adjusted odds ratio 5.82 (95% confidence interval (CI) = 2.15-15.76, p = 0.001). Infectious episodes in clozapine patients were not related to changes in neutrophil counts. Incident infection in the clozapine group was highest in the first 3 months of treatment. The most commonly reported infection in the clozapine group was chest infection; however, the majority of infections were non-chest-related. CONCLUSION: Patients starting clozapine showed a substantially increased likelihood of infection compared with patients starting PPLAI.

The Switch From Paliperidone Long-Acting Injectable 1- to 3-Monthly: Clinical Pharmacokinetic Evaluation in Patients With Schizophrenia (Preliminary Data).

PURPOSE/BACKGROUND: The aim of the study was a preliminary evaluation of the maintenance of clinical efficacy and tolerability of paliperidone palmitate in patients with schizophrenia during the transition phase from 1-monthly paliperidone palmitate formulation (PP1M) to PP3M, with the evaluation of plasma levels of the drug. METHODS/PROCEDURES: A prospective observational study was conducted for 13 months involving 22 outpatients, aged 18 to 66 years and clinically stabilized. Patients were affected by schizophrenia according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria. For each patient, clinical assessment, safety and tolerability, and drug plasma level determination were performed. Clinical efficacy was assessed by Brief Psychiatric Rating Scale, Positive and Negative Symptom Scale, and Hamilton Rating Scale for Depression. During the first 4 months of the study, once-monthly paliperidone palmitate was administered, and then during the following 9 months, the 3-monthly formulation was administered. FINDINGS/RESULTS: The time course of the Brief Psychiatric Rating Scale total scores showed a statistically significant (P = 0.006) improvement from T0 to T8; Positive and Negative Symptom Scale scores showed a similar time course, with a statistically significant (P = 0.0016) reduction of the mean total score; Hamilton Rating Scale for Depression mean scores showed a statistically significant (P = 0.003) reduction with substantial maintenance of clinical stabilization of the patients. Only 1 patient dropped out after the first PP3M injection. IMPLICATIONS/CONCLUSIONS: Our preliminary data currently confirm the maintenance of clinical stability shifting from PP1M to PP3M.

Protocolo Clínico e Diretrizes Terapêuticas (PCDT) complementares de esquizofrenia no Estado de Goiás - versão 2022 / Clinical protocol and complementary therapeutic guidelines (PCDT) for schizophrenia in the State of Goiás - version 2022

Protocolo estadual que complementa o PCDT do Ministério da Saúde e ambos devem ser considerados como referência diagnóstica e terapêutica pelos profissionais de saúde, em Goiás, para o tratamento de pessoas com o transtorno de esquizofrenia. A esquizofrenia é um transtorno mental grave que ocorre em cerca de 1% da população, independente de nível sociocultural. É caracterizada por períodos de intensas distorções do pensamento e da percepção (surtos) e pela inadequação e embotamento do afeto. Ao longo do tempo, pode aparecer prejuízos cognitivos em uma parcela significativa dos pacientes , principalmente os que não seguem tratamento regular

State protocol that complements the Ministry of Health's PCDT and both should be considered as a diagnostic and therapeutic reference by health professionals in Goiás for the treatment of people with schizophrenia disorder. Schizophrenia is a serious mental disorder that occurs in around 1% of the population, regardless of sociocultural level. It is characterized by periods of intense distortions of thought and perception (outbreaks) and by inadequacy and blunting of affect. Over time, cognitive impairment may appear in a significant portion of patients, especially those who do not follow regular treatment

Persistence With and Adherence to Paliperidone Palmitate Once-Monthly Injection for Schizophrenia Treatment in China and Japan.

Objective: To describe persistence with and adherence to paliperidone palmitate once-monthly injection (PP1M) compared to oral second-generation antipsychotics (SGAs) in patients with schizophrenia in real-world settings in China and Japan.Methods: Patients with a schizophrenia diagnosis (ICD-10: F20.x) who received oral or injectable antipsychotics from study start (China: January 1, 2012; Japan: January 1, 2014) until December 31, 2017, were enrolled in this retrospective cohort study. The first PP1M or oral SGA prescription date during the study period was defined as the index date. Eligible patients were followed up for up to 1 year after the index date. Persistence was measured from the index date until discontinuation or reaching 1 year. Adherence was assessed by calculating the proportion of days covered (PDC). Multivariable regression models were used to adjust for potential confounders.Results: The study cohorts comprised 44,266 patients from Japan and 7,564 and 5,189 patients, respectively, from 2 hospitals in China. The PP1M group showed consistently lower risk of discontinuation; adjusted hazard ratios and 95% CIs were 0.75 (0.72-0.90) (Japan), and 0.76 (0.68-0.84) and 0.65 (0.56-0.76) (China) compared to oral SGAs. The PP1M group also showed better adherence; adjusted odds ratios and 95% CIs were 1.61 (1.22-2.11) (Japan), and 1.92 (1.53-2.41) and 2.25 (1.58-3.23) (China).Conclusions: Persistence and adherence were significantly higher in PP1M users than in oral SGAs users across 3 databases comprising patients in 2 countries in Asia.

Modulation of the clinically accessible gelation time using glucono-d-lactone and pyridoxal 5'-phosphate for long-acting alginate in situ forming gel injectable.

The purpose of this study was to design alginate in situ forming gel (ISFG) injectable with clinically acceptable gelation time and controlled release of hydrophobic drug. Milled or unmilled paliperidone palmitate (PPP) was used. The gelation time was controlled by varying the ratios of glucono-d-lactone (GDL) and pyridoxal 5'-phosphate (PLP) in prefilled alginate solution mixtures (ASMs) containing PPP, CaCO3, GDL and PLP for clinically acceptable injectability. However, the gelation time was varied by the alginate type (M/G ratio), storage condition, and drug solubilizers. This ISFG exhibited 32.15 kPa of the maximal compressive stress without causing pain and stiffness. The ISFG containing conically milled PPP released PPP in a controlled manner without exhibiting any initial burst release for 4 weeks. The current alginate ISFG injectable using new combination of PLP and GDL could be used to deliver long-acting injectable drugs.

Oral and Palmitate Paliperidone Long-Acting Injectable Formulations' Use in Schizophrenia Spectrum Disorders: A Retrospective Cohort Study from the First Episode Psychosis Intervention Program (CRUPEP).

BACKGROUND: Long-acting injectable antipsychotics (LAIs) may be a suitable therapeutic option for those patients in earlier stages of psychosis to avoid relapses and disease progression. Despite that, there is a lack of evidence in the literature regarding the use of LAIs in this profile of patients. METHODS: This is a retrospective cohort analysis to assess the efficacy, tolerability, and pattern of use of palmitate paliperidone long-acting injectable (PPLAI) formulations (1- and 3-month doses) compared to oral paliperidone/risperidone in patients with a nonaffective first episode of psychosis (FEP) over 12 months of follow-up. Relevant sociodemographic and clinical information were assessed, as well as main clinical scales: Positive and Negative Syndrome Scale, Personal and Social Performance Scale, and Clinical Global Impression Scale Improvement and Severity measures. RESULTS: The study included 48 patients, 16 per arm, who were aged 20-50 years and had an FEP. Significant improvements were registered for all treatment groups. Despite that, patients receiving PPLAI 1- and 3-month formulations obtained greater improvements than those in the oral group in the main domains assessed (P < .001). We found no statistically significant differences in hospitalizations between groups. Side effects were presented in 24% of patients. A trend towards reducing antipsychotic doses was observed in 43.8% of patients to achieve the minimum effective dose and avoid the occurrence of side effects. CONCLUSIONS: To our knowledge, this is the first study assessing the use of palmitate paliperidone long-acting formulations versus oral risperidone or paliperidone in FEP. Treatment with PPLAI formulations seems to be an effective therapeutic choice at earlier stages of the disease.

Clinical response in patients treated with once-monthly paliperidone palmitate: analysis of a therapeutic drug monitoring (TDM) database.

To investigate pharmacokinetic correlates of clinical response in patients treated with once-monthly paliperidone palmitate (PP1M) injections at steady state. Plasma concentrations and dose-adjusted-plasma concentrations (C/D) of paliperidone from a naturalistic therapeutic drug monitoring (TDM) database were compared between responders and non-responders using the Clinical Global Impressions-Improvement scale (CGI-I) ratings. Analyses were based on the non-parametric Mann-Whitney U test and the Pearson Chi-squared test (χ2) with a significance level of 0.05. Subgroup analyses were performed separately in patients with schizophrenia spectrum, schizoaffective disorders and bipolar disorders. Comparing 93 responders with 80 non-responders, we detected no significant differences in the proportion of females, age, and body mass index (p's ranging 0.18-0.83); there were more smokers in the group of non-responders (p = 0.04), which also included more patients with bipolar disorders (p = 0.014). Despite the lack of differences for prescribed PP1M doses and dose intervals (p = 0.42 and p = 0.11, respectively), non-responders had higher paliperidone plasma concentrations and C/D levels (p = 0.033 and p = 0.021, respectively). Subgroup analyses did not yield differences for paliperidone plasma and C/D levels between non-responders and responders with schizophrenia spectrum (p = 0.099 and p = 0.14, respectively) and bipolar disorders (p = 0.95 and p = 0.75, respectively); dose-adjusted plasma concentrations were higher in non-responders compared to responders with schizoaffective disorders (p = 0.039), while no differences were reported for plasma levels (p = 0. 15). Our results show that paliperidone plasma concentrations over injection doses may be associated with patterns of clinical response suggesting potential utility of TDM as part of PP1M-based maintenance treatment.