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.

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.

A systematic review of the real-world effectiveness and economic and humanistic outcomes of selected oral antipsychotics among patients with schizophrenia in the United States: Updating the evidence and gaps.

BACKGROUND: Schizophrenia is a chronic, relapsing, and burdensome psychiatric disorder affecting approximately 0.25%-0.6% of the US population. Oral antipsychotic treatment (OAT) remains the cornerstone for managing schizophrenia. However, nonadherence and high treatment failure lead to increased disease burden and medical spending. Cost-effective management of schizophrenia requires understanding the value of current therapies to facilitate better planning of management policies while addressing unmet needs. OBJECTIVE: To review existing evidence and gaps regarding real-world effectiveness and economic and humanistic outcomes of OATs, including asenapine, brexpiprazole, cariprazine, iloperidone, lumateperone, lurasidone, olanzapine/samidorphan, paliperidone, and quetiapine. METHODS: We conducted a literature search using PubMed, American Psychological Association PsycINFO (EBSCOhost), and the Cumulative Index of Nursing and Allied Health Literature from January 2010 to March 2022 as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. English-language articles describing adults with schizophrenia receiving at least 1 of the selected OATs and reporting real-world effectiveness, direct or indirect costs, humanistic outcomes, behavioral outcomes, adherence/persistence patterns, or product switching were identified. RESULTS: We identified 25 studies from a total of 24,190 articles. Real-world effectiveness, cost, and adherence/persistence outcomes were reported for most OATs that were selected. Humanistic outcomes and product switching were reported only for lurasidone. Behavioral outcomes (eg, interpersonal relations and suicide ideation) were not reported for any OAT. The key economic outcomes across studies were incremental cost-effectiveness ratios, cost per quality-adjusted life-years, and health care costs. In studies that compared long-acting injectables (LAIs) with OATs, LAIs had a higher pharmacy and lower medical costs, while total health care cost was similar between LAIs and OATs. Indirect costs associated with presenteeism, absenteeism, or work productivity were not reported for any of the selected OATs. Overall, patients had poor adherence to OATs, ranging between 20% and 61% across studies. Product switching did not impact the all-cause health care costs before and after treatment. CONCLUSIONS: Our findings showed considerable gaps exist for evidence on behavioral outcomes, humanistic outcomes, medication switching, and adherence/persistence across OATs. Our findings also suggest an unmet need regarding treatment nonadherence and lack of persistence among patients receiving OATs. We identified a need for research addressing OATs' behavioral and humanistic outcomes and evaluating the impact of product switching in adults with schizophrenia in the United States, which could assist clinicians in promoting patient-centered care and help payers understand the total value of new antipsychotic drugs.

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.

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.

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.

A multicenter, single-arm, open-label interventional study of adherence to brexpiprazole during switching from previous antipsychotic drugs in patients with schizophrenia or schizoaffective disorder.

The rate of medication persistence was examined in patients with schizophrenia or schizoaffective disorder during switching from previously administered antipsychotics to brexpiprazole, a new dopamine D2 receptor partial agonist. A multicenter, single-arm, open-label 24-week interventional study was conducted, consisting of two 12-week consecutive periods: an initial switch (by plateau cross-titration) with the subsequent period, followed by a second maintenance period. Prior antipsychotics were olanzapine or risperidone/paliperidone. The primary and secondary outcome measures were medication persistence rates after the first 12 weeks and changes from baseline in the Specific Levels of Functioning Scale (SLOF), Subjective Well-being under Neuroleptic drug treatment Short form (SWNS), and Positive and Negative Syndrome Scale (PANSS) scores, respectively. In total, 79 patients were administered brexpiprazole and the medication persistence rate at 12 weeks was 78.5%, which was significantly higher than the predefined threshold of 65%. Regarding the prior medication, the persistence rate at 12 weeks was 84.6% for olanzapine and 72.5% for risperidone/paliperidone. Significant improvements from baseline were observed in the SLOF, SWNS, and PANSS scores. There were no adverse events of concern. Thus, brexpiprazole appeared to be a suitable antipsychotic on switching from olanzapine, risperidone, or paliperidone.

Characteristics of patients with schizophrenia switching from oral antipsychotics to once-monthly paliperidone palmitate (PP1M): a systematic review.

BACKGROUND: The utilization of once-monthly paliperidone palmitate (PP1M) in schizophrenia treatment has increased due to its enhanced adherence and convenience. However, there is limited evidence on patient characteristics that may influence treatment outcomes when switching from oral antipsychotics (OAPs) to PP1M therapy. This systematic review aims to identify such patient characteristics and explore potential beneficial factors to aid healthcare professionals in clinical practice. METHODS: A systematic literature search was conducted in the PubMed, Embase, and Cochrane Library databases up to July 19, 2022. Studies related to patients with schizophrenia who had been previously treated with OAPs and switched to PP1M were identified and included. Outcomes included the Positive and Negative Syndrome Scale (PANSS) total score, the clinical Global Impressions - Severity (CGI-S) score, the Personal and Social Performance (PSP) total score, and hospitalisation rate. Data were independently extracted and analysed. The results were presented through a narrative synthesis. RESULTS: Eleven studies with a total of 4150 patients were included, identifying nine potential characteristics. The most commonly reported characteristics was patient's prior treatment with OAPs, followed by the stage of disease, duration of illness (DI), ethnicity, reason for switching to PP1M, history of hospitalisation, time of start injection of PP1M, the PANSS and PSP total score at baseline. Patients in the acute stage, with a shorter DI, a less than 1-week time interval to PP1M injection, and a lower PANSS total score at baseline may have a trend on providing better improvements on PANSS total score. Acute stage and shorter DI also showed potential trends in reducing CGI-S score. Early initiation of PP1M, switching for reasons other than lack of efficacy, and a higher PSP score at baseline exhibited potential trends towards better PSP total score improvements. CONCLUSION: Our findings may suggest that patients in acute stage, with a shorter duration of illness, with early initiation of PP1M injection, and lower PANSS or PSP scores may trend towards better clinical results when transitioning to PP1M from OAPs. Further research is necessary to validate these potential associations and identify any unexplored characteristics. Such investigations are crucial for providing comprehensive clinical recommendations and informing treatment strategies in this context.

Factors Associated with Symptom Stabilization that Allow for Successful Transition from Once-Monthly Paliperidone Palmitate to Three-Monthly Paliperidone Palmitate: A Post Hoc Analysis Examined Clinical Characteristics in Chinese Patients with Schizophrenia.

BACKGROUND AND OBJECTIVES: Identifying key factors for a successful transition from once-monthly paliperidone palmitate (PP1M) to three-monthly paliperidone palmitate (PP3M) is crucial for improving treatment outcomes, enhancing patient adherence, and reducing relapse risk in patients with schizophrenia. Providing region-specific insights for evidence-based clinical decisions can aid clinicians in optimizing transition strategies for Chinese patients with schizophrenia. Therefore, the objective of this post hoc analysis of a double-blind parallel-group multicenter phase 3 study (NCT01515423) was to identify factors related to the disease stabilization that may allow for a successful transition from PP1M to PP3M in the treatment of Chinese patients with schizophrenia. METHODS: Adults (18-70 years) diagnosed with schizophrenia using the Diagnostic and Statistical Manual of Mental Disorders, fourth edition text revision, for over 1 year and with a baseline Positive and Negative Syndrome Scale (PANSS) total score between 70 and 120 were entered into an open-label (OL) phase receiving PP1M for 17 weeks. After the 17-week OL phase, patients who met the criteria necessary for stabilization were randomized (1:1) to PP1M (fixed-dose, 50, 75, 100, or 150 mg eq.) or PP3M (fixed-dose, 175, 263, 350, or 525 mg eq.) in a 48-week double-blind phase. Stabilization was defined as a PANSS total score < 70, PANSS item (P1, P2, P3, P6, P7, G8, G14) scores ≤ 4, and a reduction in Clinical Global Impression Severity (CGI-S) score of ≥ 1 from OL baseline. This post hoc analysis evaluated changes and trends in symptom severity using PANSS, changes in mental states using CGI-S, and changes in personal and social functioning using Personal and Social Performance (PSP) scores from baseline to the endpoint of the OL phase in patients who either met or did not meet the stabilization criteria (stabilized versus non-stabilized group). Comparison of changes and trends in the clinical scores between the stabilized group and non-stabilized group were conducted using linear mixed model and Mann-Kendall trend analysis, respectively. Univariate and multivariate logistic regression analyses were conducted to explore factors associated with stabilization status for transition. RESULTS: Of 296 patients enrolled, 210 achieved disease stabilization (106 patients and 104 patients were randomized to PP1M and PP3M, respectively). Significant downward trends in the PANSS and CGI-S scores were detected in the stabilized patients (n = 210, ZPANSS = -2.21, p = 0.028; ZCGI-S = -2.21, p = 0.028) but not in the non-stabilized patients (n = 86). No significant trends in the PSP scores were observed in either group. The factors significantly associated with disease stabilization were the CGI-S score at baseline [odds ratio (OR) = 0.22, 95% confidence interval (CI): 0.09, 0.5), reduction of the PANSS score at week 13 (OR = 1.11, 95% CI: 1.06, 1.17), and reduction of CGI-S score at week 13 (OR = 2.27, 95% CI: 1.03, 5.02). CONCLUSION: A lower CGI-S total score at baseline and greater reductions in PANSS and CGI-S scores at week 13 were associated with patients achieving disease stabilization, that may allow for a successful transition. Evidence from this study indicates that better disease condition at baseline, early functional improvement and symptomatic relief were the key factors associated with disease stabilization. The findings may guide clinicians to identify suitable patients for transition from PP1M to PP3M and further optimize the use of PP3M in China. CLINICAL TRIALS REGISTRATION: EudraCT number: 2011-004889-15 and ClinicalTrials.gov (identifier: NCT01515423) for the original double-blind randomized study.

Mortality and Lithium-Protective Effects after First-Episode Mania Diagnosis in Bipolar Disorder: A Nationwide Retrospective Cohort Study in Taiwan.

INTRODUCTION: This study aimed to estimate all-cause mortality in patients after a first-episode mania (FEM) and examine whether six guideline-recommended medications can reduce mortality. METHODS: The cohort included population-based FEM samples and matched controls from Taiwan, spanning 2007 to 2018. The primary outcomes assessed were all-cause/suicide-related mortality, while the secondary outcome focused on mortality associated with pharmacological treatments. We compared mortality in post-FEM patients and age-/sex-matched controls without any diagnosed bipolar disorders and patients with and without psychopharmacological treatment using Cox regression analysis, respectively. Statistics were presented with time-to-event adjusted hazard ratios (AHRs) and 95% confidence intervals (CIs). RESULTS: The study included 54,092 post-FEM patients and 270,460 controls, totaling 2,467,417 person-years of follow-up. Post-FEM patients had higher risks of all-cause mortality (AHR 2.38, 95% CI: 2.31-2.45) and suicide death (10.80, 5.88-19.84) than controls. Lithium (0.62, 0.55-0.70), divalproex (0.89, 0.83-0.95), and aripiprazole (0.81, 0.66-1.00) were associated with reduced all-cause mortality compared to non-users. There were no significant all-cause mortality differences for quetiapine (0.95, 0.89-1.01), risperidone (0.92, 0.82-1.02), and paliperidone (1.24, 0.88-1.76) users. When accounting for drug action onset times in sensitivity analyses, only lithium significantly reduced all-cause mortality (AHR range 0.65-0.72). There were 35 and 16 suicide deaths in post-FEM patients and controls, respectively. No drug had a significant effect on suicide deaths (lithium: 6; divalproex: 7; aripiprazole: 0; quetiapine: 10; risperidone: 4; paliperidone: 1). CONCLUSION: Post-FEM patients had a higher risk of all-cause/suicide-related mortality, and lithium treatment might reduce all-cause mortality.

A randomized, prospective, active-controlled study comparing intramuscular long-acting paliperidone palmitate versus oral antipsychotics in patients with schizophrenia at risk of violent behavior.

OBJECTIVE: Paliperidone palmitate (PP) is an effective long-acting antipsychotic injection, but its impact on the behavior of schizophrenia patients with dangerous tendencies requires further investigation. This study aims to explore the effects of long-term antipsychotic treatment on this population in the community. METHODS: This 49-week, randomized controlled trial was conducted across 21 communities in Wuhan and enrolled 134 schizophrenia patients at risk for violent behavior. With a fixed block size of 10, participants were randomly assigned to receive either intramuscular PP 1-month formulation (PP1M) or oral antipsychotic medication (OAP) at a 1:1 ratio. Changes in patients' risk for violent/aggressive behavior, family burden, social, and cognitive functioning were measured using VRAPP, MOAS, PANSS, FBS, PSP, and RBANS scales from baseline to endpoint. Longitudinal data from multiple repeated measures were analyzed using linear mixed-effects models. RESULTS: The study protocol was completed by 77.6% of the patients overall. Significant improvements were observed in the risk assessment scores, MOAS total score, PANSS total score, PSP total score, and FBS total score of patients in the PP1M group from baseline to the end of treatment (all P < 0.05). Importantly, compared to patients in the OAP group, the improvements in these measures were also significantly greater in the PP1M group. Commonly observed AEs, such as hyperprolactinemia (70.3% vs. 62.65%) and muscle tension (45.3% vs. 57.8%), were considered to be the PP-related AEs. Nonetheless, the differences between the two groups did not reach statistical significance, and no new safety concerns emerged. CONCLUSIONS: Our study suggests that PP long-acting injection (LAI) is a safe and effective treatment option for community-dwelling schizophrenia patients with impulsive violence and risky behaviors.

Factors influencing concentrations of risperidone and 9-hydroxyrisperidone in psychiatric outpatients taking immediate-release formulations of risperidone.

OBJECTIVES: To analyze the factors affecting the concentrations of the active moiety of risperidone (RIS) and its active metabolite 9-hydroxyrisperidone (9-OH-RIS) in psychiatric outpatients taking immediate-release formulations. METHODS: This is a retrospective study on the therapeutic drug monitoring (TDM) data regarding RIS and 9-OH-RIS in adult psychiatric outpatients. TDM data with simultaneous RIS and 9-OH-RIS monitoring from March 2018 to February 2020 and relevant medical records (including dosage, dosage form, sex, age, diagnosis, combined medication, and comorbid disease) from 399 adult psychiatric outpatients (223 males and 176 females) were included in this study. RESULTS: The daily dose of RIS was 5.56 ± 2.05 mg, the concentration of total active moiety was 42.35 ± 25.46 ng/mL, and the dose-adjusted plasma concentration (C/D) of active moiety was 7.83 ± 3.87 (ng/ml)/(mg/day). Dose, sex, and age were identified as important factors influencing concentrations of RIS and 9-OH-RIS in adult psychiatric outpatients. CONCLUSIONS: Individualized medication adjustments should be made according to the specific conditions of psychiatric outpatients. The findings strongly support the use of TDM to guide dosing decisions in psychiatric outpatients taking RIS.

Evidence for solanidine as a dietary CYP2D6 biomarker: Significant correlation with risperidone metabolism.

AIMS: The extensive variability in cytochrome P450 2D6 (CYP2D6) metabolism is mainly caused by genetic polymorphisms. However, there is large, unexplained variability in CYP2D6 metabolism within CYP2D6 genotype subgroups. Solanidine, a dietary compound found in potatoes, is a promising phenotype biomarker predicting individual CYP2D6 metabolism. The aim of this study was to investigate the correlation between solanidine metabolism and the CYP2D6-mediated metabolism of risperidone in patients with known CYP2D6 genotypes. METHODS: The study included therapeutic drug monitoring (TDM) data from CYP2D6-genotyped patients treated with risperidone. Risperidone and 9-hydroxyrisperidone levels were determined during TDM, and reprocessing of the respective TDM full-scan high-resolution mass spectrometry files was applied for semi-quantitative measurements of solanidine and five metabolites (M402, M414, M416, M440 and M444). Spearman's tests determined the correlations between solanidine metabolic ratios (MRs) and the 9-hydroxyrisperidone-to-risperidone ratio. RESULTS: A total of 229 patients were included. Highly significant, positive correlationswere observed between all solanidine MRs and the 9-hydroxyrisperidone-to-risperidone ratio (ρ > 0.6, P < .0001). The strongest correlation was observed for the M444-to-solanidine MR in patients with functional CYP2D6 metabolism, i.e., genotype activity scores of 1 and 1.5 (ρ 0.72-0.77, P < .0001). CONCLUSION: The present study shows strong, positive correlations between solanidine metabolism and CYP2D6-mediated risperidone metabolism. The strong correlation within patients carrying CYP2D6 genotypes encoding functional CYP2D6 metabolism suggests that solanidine metabolism may predict individual CYP2D6 metabolism, and hence potentially improve personalized dosing of drugs metabolized by CYP2D6.

Long-Acting Injectable Second-Generation Antipsychotics vs Placebo and Their Oral Formulations in Acute Schizophrenia: A Systematic Review and Meta-Analysis of Randomized-Controlled-Trials.

BACKGROUND AND HYPOTHESIS: Long-acting injectable antipsychotic drugs (LAIs) are mainly used for relapse prevention but could also be advantageous for acutely ill patients with schizophrenia. STUDY DESIGN: We conducted a systematic review and meta-analysis of randomized-controlled-trials (RCTs) comparing the second-generation long-acting injectable antipsychotics (SGA-LAIs) olanzapine, risperidone, paliperidone, and aripiprazole with placebo or their oral counterparts in acutely ill patients with schizophrenia. We analyzed 23 efficacy and tolerability outcomes, with the primary outcome being overall symptoms of schizophrenia. The results were obtained through random effects, pairwise meta-analyses, and subgroup tests. The study quality was assessed using the Cochrane-Risk-of-Bias-Tool version-1. STUDY RESULTS: Sixty-six studies with 16 457 participants were included in the analysis. Eleven studies compared second-generation long-acting injectable antipsychotics (SGA-LAIs) with a placebo, 54 compared second-generation oral antipsychotics (SGA-orals) with a placebo, and one compared an SGA-LAI (aripiprazole) with its oral formulation. All 4 SGA-LAIs reduced overall symptoms more than placebo, with mean standardized differences of -0.66 (95% CI: -0.90; -0.43) for olanzapine, -0.64 (-0.80; -0.48) for aripiprazole, -0.62 (-0.76; -0.48) for risperidone and -0.42 (-0.53; -0.31) for paliperidone. The side-effect profiles of the LAIs corresponded to the patterns known from the oral formulations. In subgroup tests compared to placebo, some side effects were less pronounced under LAIs than under their oral formulations. CONCLUSIONS: SGA-LAIs effectively treat acute schizophrenia. Some side effects may be less frequent than under oral drugs, but due to the indirect nature of the comparisons, this finding must be confirmed by RCTs comparing LAIs and orals head-to-head.

An association between PPARα-L162V polymorphism and increased plasma LDL cholesterol levels after risperidone treatment.

Peroxisome proliferator-activated receptor alpha (PPARα) and antipsychotic medications both influence polyunsaturated fatty acids (PUFA) homeostasis, and thus PPARα polymorphism may be linked to antipsychotic treatment response. Here we investigated whether the functional leucine 162 valine (L162V) polymorphism in PPARα influenced antipsychotic treatment in a group of psychosis patients (N = 186), as well as in a patient subgroup with risperidone, paliperidone, or combination treatment (N = 65). Antipsychotic-naïve first-episode patients and nonadherent chronic individuals were genotyped by polymerase chain reaction analysis. At baseline, and after 8 weeks of treatment with various antipsychotic medications, we assessed the patients' Positive and Negative Syndrome Scale (PANSS) scores; PANSS factors; and metabolic syndrome-related parameters, including fasting plasma lipid and glucose levels, and body mass index. In the total patient group, PPARα polymorphism did not affect PANSS psychopathology or metabolic parameters. However, in the subgroup of patients with risperidone, paliperidone, or combination treatment, PPARα polymorphism influenced changes in plasma LDL cholesterol. Specifically, compared to PPARα-L162L homozygous patients, PPARα-L162V heterozygous individuals exhibited significantly higher increases of LDL cholesterol levels after antipsychotic treatment. The PPARα polymorphism had a strong effect size, but a relatively weak contribution to LDL cholesterol level variations (∼12.8 %).

The role of alkyl chain length in the melt and solution crystallization of paliperidone aliphatic prodrugs.

Fatty acid-derivative prodrugs have been utilized extensively to improve the physicochemical, biopharmaceutical and pharmacokinetic properties of active pharmaceutical ingredients. However, to our knowledge, the crystallization behavior of prodrugs modified with different fatty acids has not been explored. In the present work, a series of paliperidone aliphatic prodrugs with alkyl chain lengths ranging from C4 to C16 was investigated with respect to crystal structure, crystal morphology and crystallization kinetics. The paliperidone derivatives exhibited isostructural crystal packing, despite the different alkyl chain lengths, and crystallized with the dominant (100) face in both melt and solution. The rate of crystallization for paliperidone derivatives in the melt increases with alkyl chain length owing to greater molecular mobility. In contrast, the longer chains prolong the nucleation induction time and reduce the crystal growth kinetics in solution. The results show a correlation between difficulty of nucleation in solution and the interfacial energy. This work provides insight into the crystallization behavior of paliperidone aliphatic prodrugs and reveals that the role of alkyl chain length in the crystallization behavior has a strong dependence on the crystallization method.

Inflammation affects the pharmacokinetics of risperidone: Does the dose need to be adjusted during the acute-phase reaction?

BACKGROUND: Several studies have indicated that the plasma concentration of risperidone increases 3-5-fold during the acute-phase reaction (APR) of inflammation or infection. Psychiatric symptoms are present or deteriorate when the dose is lowered; thus, the complex effects of inflammation on the pharmacokinetics of risperidone need to be examined. METHODS: We established a APR model in rabbits induced by lipopolysaccharide (LPS) and studied the effect of APR on pharmacokinetics, distribution and disposition of risperidone in vivo and in vitro. RESULTS: Following intramuscular administration, the plasma exposures for risperidone and its active metabolite (9-hydroxyrisperidone) were increased approximately 6-fold on day 2 of inflammation. The exposure values did not change between day 2 and 5 of inflammation, nor did the metabolite-to-parent ratio before and during inflammation. Following oral administration, the increase of risperidone exposure was twice as high as that following intramuscular administration during APR. However, the concentration of risperidone and 9-hydroxyrisperidone in brain tissue was similar between the inflammatory and control groups. Moreover, the plasma protein binding (PPB) of risperidone and 9-hydroxyrisperidone associated with inflammation were all increased to >99 %. In addition, risperidone and 9-hydroxyrisperidone were not substrates of the key transporters, OATP1B3, OCT2, OAT3, MATE-1, or MATE-2 K. The expression of progesterone X receptor and P-glycoprotein was inhibited by LPS. CONCLUSION: During APR, reduced expression of P-glycoprotein and increased PPB were responsible for increased exposure in plasma, while maintaining stable concentrations in the brain, and risperidone does not need to be dose-adjusted so as to achieve psychopharmacological outcomes.

Clozapine augmentation with long-acting antipsychotic injections: A case series and systematic review.

BACKGROUND: Up to 30% of patients with a diagnosis of treatment-resistant psychosis remain symptomatic despite an optimal trial with the gold standard treatment, clozapine. Emerging evidence suggests the clinical utility of long-acting injections (LAI) in such clinical scenarios. In this study, we aimed to describe clozapine augmentation with LAIs in an inner London hospital and explore the literature on the clinical effectiveness of this treatment modality. METHODS: Patients prescribed clozapine, who were commenced on a LAI between 2007 and 2023 by the United Kingdom's largest mental health trust, were identified from electronic patient records. First, routine clinical data were used to describe the use, effectiveness, and safety of this augmentation strategy. Second, we conducted a literature search up to 1st June 2023 to identify published studies describing clinical outcomes after clozapine augmentation with a LAI. Clinical outcomes were collated and presented in a table, including hospitalisation rates and quantitative clinical assessments using validated scales. RESULTS: Of the 1248 patients prescribed clozapine in SLaM, three patients (0.2%) received augmentation with the following LAIs: olanzapine embonate, paliperidone palmitate and pipotiazine palmitate. This treatment strategy was clinically effective and generally well tolerated in all three cases. Twelve published studies between 2010 and 2022 were included in the review. Eight distinct LAIs were reported (4 first and 4 second generation antipsychotics), with risperidone and paliperidone most widely studied. All the identified studies were observational including mirror-image studies, case series and case reports. Duration of follow up varied from 3 months to 3 years. There was evidence that the use of LAIs with clozapine can significantly reduce clinical symptoms, hospitalisation rates and bed days. No serious adverse effects were reported. CONCLUSION: This preliminary evidence suggests clinical utility of LAIs in alleviating residual symptoms and subsequently reducing hospitalisation rates in patients optimised on clozapine treatment. The current study warrants further investigations including a randomised controlled study to establish the clinical efficacy, tolerability, and place in therapy of this treatment modality.