Anismus-A Very Unusual Extrapyramidal Side Effect of Paliperidone Palmitate in an Adolescent with Schizo-Affective Disorder.

Here, authors report on an interesting case of an adolescent with a diagnosis of schizo-affective disorder, maintained on LAI paliperidone palmitate that developed an unusual dystonic reaction in form of anismus that masquerade as constipation and faecal impaction. To our knowledge, this is one of the earliest reports of antipsychotic-induced anismus notably in adolescent population. Clinicians should be mindful of unusual forms of dyskinesias that might be associated with high-potency antipsychotic use.

Three-Year Outcomes of 6-Month Paliperidone Palmitate in Adults With Schizophrenia: An Open-Label Extension Study of a Randomized Clinical Trial.

Importance: Long-acting injectable (LAI) antipsychotics have the potential to improve adherence and symptom control in patients with schizophrenia, promoting long-term recovery. Paliperidone palmitate (PP) once every 6 months is the first and currently only LAI antipsychotic with an extended dosing interval of 6 months. Objective: To assess long-term outcomes of PP received once every 6 months in adults with schizophrenia. Design, Setting, and Participants: In a 2-year open-label extension (OLE) study of a 1-year randomized clinical trial (RCT), eligible adults with schizophrenia could choose to continue PP every 6 months if they had not experienced relapse after receiving PP once every 3 or 6 months in the 1-year, international, multicenter, double-blind, randomized noninferiority trial. The present analysis focused on patients receiving PP every 6 months in the double-blind trial through the OLE study (November 20, 2017, to May 3, 2022). Intervention: Patients received a dorsogluteal injection of PP on day 1 and once every 6 months up to month 30. Main Outcomes and Measures: End points included assessment of relapse and change from the double-blind trial baseline to the OLE end point in Positive and Negative Syndrome Scale (PANSS) total and subscale, Clinical Global Impression-Severity (CGI-S) Scale, and Personal Social Performance (PSP) Scale scores. Treatment-emergent adverse events (TEAEs), injection site evaluations, and laboratory tests were also assessed. Results: Among 121 patients (83 [68.6%] male), mean (SD) age at baseline was 38.6 (11.24) years and mean (SD) duration of illness was 11.0 (9.45) years. At screening of the double-blind study, 101 patients (83.5%) were taking an oral antipsychotic and 20 (16.5%) were taking an LAI antipsychotic. Altogether, 5 of 121 patients (4.1%) experienced relapse during the 3-year follow-up; reasons for relapse were psychiatric hospitalization (2 [1.7%]), suicidal or homicidal ideation (2 [1.7%]), and deliberate self-injury (1 [0.8%]). Patients treated with PP every 6 months were clinically and functionally stable, and outcomes were well maintained, evidenced by stable scores on the PANSS (mean [SD] change, -2.6 [9.96] points), CGI-S (mean [SD] change, -0.2 [0.57] points), and PSP (mean [SD] change, 3.1 [9.14] points) scales over the 3-year period. In total, 101 patients (83.5%) completed the 2-year OLE. At least 1 TEAE was reported in 97 of 121 patients (80.2%) overall; no new safety or tolerability concerns were identified. Conclusions and Relevance: In a 2-year OLE study of a 1-year RCT, results supported favorable long-term outcomes of PP once every 6 months for up to 3 years in adults with schizophrenia.

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.

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.

Dissolving microarray patches for transdermal delivery of risperidone for schizophrenia management.

Schizophrenia is a psychiatric disorder that results from abnormal levels of neurotransmitters in the brain. Risperidone (RIS) is a common drug prescribed for the treatment of schizophrenia. RIS is a hydrophobic drug that is typically administered orally or intramuscularly. Transdermal drug delivery (TDD) could potentially improve the delivery of RIS. This study focused on the development of RIS nanocrystals (NCs), for the first time, which were incorporated into dissolving microneedle array patches (DMAPs) to facilitate the drug delivery of RIS. RIS NCs were formulated via wet-media milling technique using poly(vinylalcohol) (PVA) as a stabiliser. NCs with particle size of 300 nm were produced and showed an enhanced release profile up to 80 % over 28 days. Ex vivo results showed that 1.16 ± 0.04 mg of RIS was delivered to both the receiver compartment and full-thickness skin from NCs loaded DMAPs compared to 0.75 ± 0.07 mg from bulk RIS DMAPs. In an in vivo study conducted using female Sprague Dawley rats, both RIS and its active metabolite 9-hydroxyrisperidone (9-OH-RIS) were detected in plasma samples for 5 days. In comparison with the oral group, DMAPs improved the overall pharmacokinetic profile in plasma with a âˆ¼ 15 folds higher area under the curve (AUC) value. This work has represented the novel delivery of the antipsychotic drug, RIS, through microneedles. It also offers substantial evidence to support the broader application of MAPs for the transdermal delivery of poorly water-soluble drugs.

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.

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.

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.

Evaluating the 6-month formulation of paliperidone palmitate: a twice-yearly injectable treatment for schizophrenia in adults.

INTRODUCTION: Paliperidone Palmitate is the only antipsychotic that has been developed in three different intramuscular long-acting injectable (LAI) dosing regimen: monthly (PP1M), quarterly (PP3M), and from 2020 also twice-yearly (PP6M). The latter was approved for the maintenance treatment of adults with schizophrenia and clinically stabilized with PP1M or PP3M. AREAS COVERED: Data from studies evaluating efficacy in the maintenance treatment of schizophrenia with PP6M are reviewed. Since no post-marketing safety studies are currently available, data from spontaneous reporting system databases, FAERS and Eudravigilance, are analyzed and the reported treatment-emergent adverse events of PP6M are discussed. EXPERT OPINION: The efficacy of PP6M is comparable to that of PP3M in terms of relapses prevention in patients with schizophrenia previously stabilized on PP3M or PP1M. Also, the maintenance of clinical efficacy in the long term has been demonstrated. Data from pharmacovigilance analyses, as well as from phase 3 studies, show that PP6M is generally well tolerated, consistently with PP3M safety data. PP6M allows a longer dosing interval than any other LAI antipsychotics, potentially reducing nonadherence and disease relapses. In future, an increase in the prescription rates of PP6M is expected and real-world efficacy and tolerability studies will be conducted.

Clinical outcomes with paliperidone palmitate 3-monthly injection as monotherapy: observational 3-year follow-up of patients with schizophrenia.

BACKGROUND: Paliperidone palmitate 3-monthly (PP3M) has been tested in 1-year controlled studies. The aim of this study was to examine the relapse outcomes with PP3M monotherapy at 3 years in patients with schizophrenia. METHODS: This was an observational, non-interventional study of patients started on PP3M according to their clinical need. All patients had a diagnosis of schizophrenia (ICD-10 F20) and were between 18 and 65 years of age. The study took place in a mental health facility in South East London, UK. RESULTS: Among the 166 patients who started PP3M, 97 (58%) met inclusion criteria and were observed for 36 months. In total, five patients (5%) experienced a relapse (defined as step-up in clinical care) while on PP3M. There were no relapses between months 18 and 36. Of the original 97 patients, 56 (58%) remained on PP3M monotherapy at 3 years, and 71 (73%) remained on either PP3M or paliperidone palmitate one-monthly. Reasons for discontinuation of PP3M included patient refusal (n = 11, 33% of discontinuations) and adverse effects in (n = 8, 24%). CONCLUSION: PP3M is a highly effective monotherapy treatment for reducing relapse in people with schizophrenia.

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.

Safety and Tolerability of Starting Aripiprazole Lauroxil With Aripiprazole Lauroxil NanoCrystal Dispersion in 1 Day Followed by Aripiprazole Lauroxil Every 2 Months Using Paliperidone Palmitate Monthly as an Active Control in Patients With Schizophrenia: A Post Hoc Analysis of a Randomized Controlled Trial.

Background: Aripiprazole lauroxil (AL) 1064 mg every 2 months following initiation using the AL NanoCrystal Dispersion formulation (ALNCD) plus 30-mg oral aripiprazole was efficacious and well tolerated in a 25-week, randomized, double-blind phase 3 trial in adults with acute schizophrenia. This post hoc analysis further characterized the safety of AL 1064 mg administered every 2 months and that of active control paliperidone palmitate (PP) 156 mg monthly based on occurrence, timing, and severity of adverse events (AEs) associated with antipsychotic medications.Methods: This study was conducted between November 2017 and March 2019. AL or PP was initiated during an inpatient stay of ≥ 2 weeks with transition to outpatient treatment thereafter. Rates of AEs of clinical interest, including injection site reactions (ISRs), motor AEs, sedation, hypotension, prolactin level increase, weight gain, and suicidal ideation/behavior, were summarized through weeks 4, 9, and 25 for each treatment.Results: Of 200 patients who received ≥ 1 dose of study treatment, 99 (49.5%) completed the study (AL, 57%; PP, 43%). Mean (SD) baseline Positive and Negative Syndrome Scale total scores were 94.1 (9.04) and 94.6 (8.41) in the AL and PP treatment groups, respectively. AEs were reported by 69/99 (70%) patients administered AL and 72/101 (71%) administered PP; most AEs were mild or moderate in severity. ISRs (AL, 18.2%; PP, 26.7%) occurred primarily on days 1 and 8. All akathisia/restlessness AEs (AL, 10.1%; PP, 11.9%) occurred during the first 4 weeks; <10% of patients (either treatment) experienced hypotension, sedation, or suicidal ideation/behavior events. Weight gain of ≥ 7% from baseline occurred in 9.3% of AL- and 23.8% of PP-treated patients. Median prolactin concentrations changed by -4.60 and -3.55 ng/mL among AL-treated males and females, respectively, and did not exceed 2 times normal levels in any AL-treated patients. In PP-treated patients, changes were 21.20 and 80.40 ng/mL and concentrations exceeded 2 times normal in 38% and 88% of males and females, respectively.Conclusions: No new early- or late-emerging safety concerns were observed through 25 weeks of treatment with AL 1064 mg every 2 months following initiation using ALNCD plus 30-mg oral aripiprazole. Results were consistent with known safety profiles of AL and PP and support the safety of AL 1064 mg every 2 months initiated using ALNCD plus 30-mg oral aripiprazole.Trial Registration: ClinicalTrials.gov identifier: NCT03345979.

Relapse Rates With Paliperidone Palmitate in Adult Patients With Schizophrenia: Results for the 6-Month Formulation From an Open-label Extension Study Compared to Real-World Data for the 1-Month and 3-Month Formulations.

BACKGROUND: The 3 paliperidone palmitate (PP) long-acting injectable antipsychotic formulations, PP 1-month (PP1M), PP 3-month (PP3M), and PP 6-month (PP6M), have shown to reduce the risk of relapse in schizophrenia. The current phase-4 study constructed external comparator arms (ECAs) using real-world data for PP3M and PP1M and compared relapse prevention rates with PP6M from an open-label extension (OLE) study in adult patients with schizophrenia. METHODS: PP6M data were derived from a single-arm, 24-month, OLE study (NCT04072575), which included patients with schizophrenia who completed a 12-month randomized, double-blind, noninferiority, phase-3 study (NCT03345342) without relapse. Patients in the PP3M and PP1M ECAs were identified from the IBM® MarketScan® Multistate Medicaid Database based on similar eligibility criteria as the PP6M cohort. RESULTS: A total of 178 patients were included in each cohort following propensity score matching. Most patients were men (>70%; mean age: 39-41 years). Time to relapse (primary analysis based on Kaplan-Meier estimates) was significantly delayed in the PP6M cohort (P < .001, log-rank test). The relapse rate was lower in the PP6M cohort (3.9%) vs PP3M (20.2%) and PP1M (29.8%) cohorts. Risk of relapse decreased significantly (P < .001) by 82% for PP6M vs PP3M (HR = 0.18 [95% CI = 0.08 to 0.40]), 89% for PP6M vs PP1M (HR = 0.11 [0.05 to 0.25]), and 35% for PP3M vs PP1M (HR = 0.65 [0.42 to 0.99]; P = .043). Sensitivity analysis confirmed findings from the primary analysis. Although the ECAs were matched to mimic the characteristics of the PP6M cohort, heterogeneity between the groups could exist due to factors including prior study participation, unmeasured confounders, variations in data capture and quality, and completeness of clinical information. CONCLUSIONS: In a clinical trial setting, PP6M significantly delayed time to relapse and demonstrated lower relapse rates compared with PP3M and PP1M treatments in real-world settings among adult patients with schizophrenia. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04072575; EudraCT number: 2018-004532-30.

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.

Influence of CYP2D6 Metabolizer Status on Risperidone and Paliperidone Tolerability in Children and Adolescents.

Background: Risperidone and, to a lesser extent, paliperidone are metabolized by CYP2D6; however, there are limited data related to variation in CYP2D6 phenotypes and the tolerability of these medications in children and adolescents. Furthermore, the impact of CYP2D6 on the association of risperidone and paliperidone with hyperprolactinemia in youth is not well understood. Methods: A retrospective chart review was performed in psychiatrically hospitalized children and adolescents prescribed risperidone (n = 263, age = 3-18 years, mean age = 13 ± 3 years, 49% female) or paliperidone (n = 124, age = 5-18 years, mean age = 15 ± 2 years, 44% female) who had CYP2D6 genotyping performed as part of routine care. CYP2D6 phenotypes were determined based on Clinical Pharmacogenetics Implementation Consortium guidelines and CYP2D6 inhibitors causing phenoconversion. Adverse effects were obtained from a review of the electronic health record, and patients were selected, in part, to enrich non-normal metabolizers. Results: Among risperidone-treated patients, 45% experienced an adverse effect, whereas 36% of paliperidone-treated patients experienced adverse effects. Discontinuation of risperidone due to lack of efficacy was more frequent in the CYP2D6 normal metabolizers and ultrarapid metabolizers compared with intermediate metabolizers (IMs) and phenoconverted poor metabolizers (pPMs) (54.5% vs. 32.7%, p < 0.001). Discontinuation due to weight gain was more common among risperidone- than paliperidone-treated patients (17% vs. 7%, p = 0.011). Among those taking paliperidone, CYP2D6 was associated with discontinuation due to side effects (p = 0.008), and youth with slower CYP2D6 metabolism (i.e., pPMs and IMs) were more likely to discontinue. Hyperprolactinemia was found in 10% of paliperidone-treated patients and 5% of risperidone-treated patients, and slower CYP2D6 metabolizers required higher risperidone doses to cause hyperprolactinemia (p = 0.011). Conclusions: CYP2D6 phenotype is associated with discontinuation of risperidone due to lack of efficacy and the dose of risperidone that induced hyperprolactinemia, as well as discontinuation of paliperidone due to adverse effects. Future studies should evaluate exposure-response and toxicity relationships in risperidone- and paliperidone-treated youth.