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.

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.

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.

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.

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.

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.

Long-Term Efficacy and Safety of Paliperidone 6-Month Formulation: An Open-Label 2-Year Extension of a 1-Year Double-Blind Study in Adult Participants With Schizophrenia

BACKGROUND

Paliperidone palmitate 6-month (PP6M) demonstrated noninferiority to paliperidone palmitate 3-month in preventing relapse in patients with schizophrenia in a phase 3 double-blind (DB) study (NCT03345342). Here, we report long-term efficacy and safety results from a 2-year single-arm, open-label extension (OLE; NCT04072575) of this DB study.

METHODS

Participants who completed the DB study without relapse were enrolled and followed-up every 3 months up to 2 years. Participants received 4 PP6M gluteal injections (700/1000 mg eq.) at baseline, 6-month, 12-month, and 18-month visits. Efficacy endpoints included assessment of relapse, Positive and Negative Syndrome Scale total score, Personal and Social Performance score, and Clinical Global Impression-Severity scale change from baseline. Safety was assessed by treatment-emergent adverse events (TEAEs), physical examinations, and laboratory tests.

RESULTS

Of 178 participants enrolled, 154 (86.5%) completed the OLE (mean age: 40.4 years, men: 70.8%; mean duration of PP6M exposure during OLE: 682.1 days). Overall, 7/178 (3.9%) participants relapsed between 20 and 703 days after enrolment. Mean (SD) changes from baseline to endpoint were as follows: Positive and Negative Syndrome Scale total score, 0.7 (8.22); Clinical Global Impression-Severity, 0.0 (0.51); and Personal and Social Performance Scale, 0.5 (7.47). Overall, 111/178 participants (62.4%) reported ≥1 TEAE; most common (>5%) TEAEs were headache (13.5%) and increased blood prolactin/hyperprolactinemia (18.0%); 8/178 (4.5%) participants experienced serious TEAEs, and 6/178 (3.4%) participants withdrew due to TEAEs. No deaths were reported.

CONCLUSIONS

The relapse rate observed with PP6M during the 2-year OLE was low (3.9%). Clinical and functional improvements demonstrated in the DB study were maintained during OLE, and no new safety concerns were identified.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04072575; EudraCT number: 2018-004532-30.

Effectiveness and Safety of Switching from Oral Antipsychotics to Once-Monthly Paliperidone Palmitate (PP1M) in the Management of Schizophrenia: A Systematic Review and Meta-Analysis

BACKGROUND

Considering the improvement in adherence and convenience, once-monthly paliperidone palmitate (PP1M) has been increasingly used in the treatment of schizophrenia. However, the outcomes for patients who switch from oral antipsychotics (OAPs) to PP1M have not been reliably assessed. The objective of this systematic review and meta-analysis was to investigate the efficacy and safety of PP1M in the management of patients with schizophrenia with a prior history of OAP use.

METHODS

We conducted a systematic search in PubMed, EMBASE, and the Cochrane Library on 19 July 2022 to identify eligible studies. All studies that examined the effectiveness and safety of switching from OAPs to PP1M in patients with schizophrenia were included. The primary outcomes were relapse rate, hospitalisation rate, and the change from baseline in the Positive and Negative Syndrome Scale (PANSS) total score. The secondary outcomes included the changed number of inpatient visits, changed length of stay hospitalisation, change from baseline in the Clinical Global Impressions-Severity (CGI-S) score and the personal and social performance (PSP) total score, response rate, proportion of treatment discontinuation, and adverse events. We included randomised-controlled trials (RCTs), single-arm studies, and observational studies. Case reports, case series, and reviews were excluded. The quality assessment of included studies was performed using the Revised Cochrane risk-of-bias tool for randomised trials (RoB2), the 9-point Newcastle-Ottawa Scale (NOS) instrument for non-randomised studies and cohort studies, and the 12-item National Institutes of Health (NIH) quality assessment tool for before-after (Pre-Post) study without control group. Follow-up times were reported as short- (≤ 13 weeks), medium- (14-26 weeks), and long term (≥ 27 weeks). Data were pooled using meta-analysis.

RESULTS

Fifteen studies with a total of 4740 patients were included. The long-term relapse rates and hospitalisation rates were 12% (95% CI 0.07-0.18) and 18% (95% CI 0.15-0.20), respectively. The short-, medium-, and long-term change in PANSS total score was - 21.69 (95% CI - 30.02 to -13.36), - 14.98 (95% CI - 21.45 to - 8.51) and - 17.88 (95% CI - 31.94 to -3.82), respectively. Approximately 50% of patients reported at least a 30% reduction in the PANSS score at the short-term follow-up. Improvements in CGI-S and PSP score were observed during various periods. There was a reduction in the length of stay hospitalisation and the number of inpatient visits at the medium- and long-term follow-ups. Low discontinuation and adverse event rates were reported.

CONCLUSION

Based on our findings, this study may support the efficacy and safety of switching from OAPs to PP1M for the treatment of patients with schizophrenia. Future large-scale studies are warranted to confirm our findings.

Risperidone is not only a prodrug: psychosis induced by medication switch from risperidone to paliperidone - a case report

Once administered, risperidone is converted into its pharmacologically active form, paliperidone. Thus, their pharmacological effects are expected to be equivalent. We encountered a psychosis induced by the switch from risperidone to paliperidone.This is the case of a schizoaffective patient stabilised on risperidone long-acting injection (LAI) who consented to switch to paliperidone LAI. On day 0, he received his first dose of paliperidone. On day 86, he presented to the emergency department with an acute psychotic episode. On day 92, he committed a violent act. The patient was restarted on risperidone LAI and stabilised.Risperidone is extensively metabolised to paliperidone via CYP450 2D6. Interindividual and ethnic genetic polymorphism cause variability in CYP450 2D6 phenotypes. In this possible case of low-functioning alleles, the patient had a higher risperidone to paliperidone ratio at steady state. Although risperidone is paliperidone's prodrug, this case highlights the interindividual pharmacotherapeutic response to these two antipsychotics.

Can multisite clinical trial results change clinical practice? Use of long-acting injectable risperidone nationally in the Veterans Health Administration

BACKGROUND

Multisite practical clinical trials evaluate treatments in real-world practice. A multisite randomized Veterans Health Administration (VHA) cooperative study (CSP#555) published in 2011 compared the first long-acting injectable (LAI) second-generation antipsychotic (SGA), Risperidone Consta®, in veterans with a diagnosis of schizophrenia or schizoaffective disorder, to oral antipsychotics, with unexpected null results for effectiveness and cost-effectiveness. Whether null results of this type could change VHA practice has not been studied.

METHODS

A longitudinal observational analysis was used to evaluate the impact of the trial findings on VHA clinical practices. National administrative data compared new starts on LAI risperidone during the 4 years before the publication of CSP#555 in 2011 to new starts on LAI risperidone during the 4 years after.

RESULTS

Among 119,565 Veterans with the indicated diagnoses treated with antipsychotics from 2007 to 2015, the number and proportion of new starts on LAI risperidone declined significantly following the study publication, as did the total number of annual users and drug expenditures. However, data from 2007 to 2010 showed the decline in new starts actually preceded the publication of CSP#555. This change was likely explained by the increase in new starts, total use, and expenditures on a newer medicine, LAI paliperidone, a 4-week LAI treatment, in the 2 years prior to the publication of CSP#555.

CONCLUSIONS

The declining use of LAI risperidone likely primarily reflects the substitution of a longer-acting LAI SGA, paliperidone, that came to market 2 years before the study publication, a substitution that may have been reinforced by null CSP#555 study results for LAI risperidone.

Benefits and harms of Risperidone and Paliperidone for treatment of patients with schizophrenia or bipolar disorder: a meta-analysis involving individual participant data and clinical study reports

BACKGROUND

Schizophrenia and bipolar disorder are severe mental illnesses which are highly prevalent worldwide. Risperidone and Paliperidone are treatments for either illnesses, but their efficacy compared to other antipsychotics and growing reports of hormonal imbalances continue to raise concerns. As existing evidence on both antipsychotics are solely based on aggregate data, we aimed to assess the benefits and harms of Risperidone and Paliperidone in the treatment of patients with schizophrenia or bipolar disorder, using individual participant data (IPD), clinical study reports (CSRs) and publicly available sources (journal publications and trial registries).

METHODS

We searched MEDLINE, Central, EMBASE and PsycINFO until December 2020 for randomised placebo-controlled trials of Risperidone, Paliperidone or Paliperidone palmitate in patients with schizophrenia or bipolar disorder. We obtained IPD and CSRs from the Yale University Open Data Access project. The primary outcome Positive and Negative Syndrome Scale (PANSS) score was analysed using one-stage IPD meta-analysis. Random-effect meta-analysis of harm outcomes involved methods for coping with rare events. Effect-sizes were compared across all available data sources using the ratio of means or relative risk. We registered our review on PROSPERO, CRD42019140556.

RESULTS

Of the 35 studies, IPD meta-analysis involving 22 (63%) studies showed a significant clinical reduction in the PANSS in patients receiving Risperidone (mean difference - 5.83, 95% CI - 10.79 to - 0.87, I2 = 8.5%, n = 4 studies, 1131 participants), Paliperidone (- 6.01, 95% CI - 8.7 to - 3.32, I2 = 4.3%, n = 13, 3821) and Paliperidone palmitate (- 7.89, 95% CI - 12.1 to - 3.69, I2 = 2.9%, n = 5, 2209). CSRs reported nearly two times more adverse events (4434 vs. 2296 publication, relative difference (RD) = 1.93, 95% CI 1.86 to 2.00) and almost 8 times more serious adverse events (650 vs. 82; RD = 7.93, 95% CI 6.32 to 9.95) than the journal publications. Meta-analyses of individual harms from CSRs revealed a significant increased risk among several outcomes including extrapyramidal disorder, tardive dyskinesia and increased weight. But the ratio of relative risk between the different data sources was not significant. Three treatment-related gynecomastia events occurred, and these were considered mild to moderate in severity.

CONCLUSION

IPD meta-analysis conclude that Risperidone and Paliperidone antipsychotics had a small beneficial effect on reducing PANSS score over 9 weeks, which is more conservative than estimates from reviews based on journal publications. CSRs also contained significantly more data on harms that were unavailable in journal publications or trial registries. Sharing of IPD and CSRs are necessary when performing meta-analysis on the efficacy and safety of antipsychotics.

Hepatitis C virus and hepatitis B virus in patients with schizophrenia

This study evaluated the severe hepatic outcome (SHO) in patients with schizophrenia and viral hepatitis who received antipsychotics.Using the nationwide Taiwan National Health Insurance Research Database, patients first diagnosed with schizophrenia between 2002 and 2013 were identified. Patients diagnosed with schizophrenia who had viral hepatitis, including hepatitis B virus (HBV) or hepatitis C virus (HCV), were designated as the viral hepatitis group. A control group without viral hepatitis was matched for age, sex, and index year in a 2:1 ratio. Patients with severe hepatic outcomes before enrollment were excluded. The 2 cohorts were observed until December 31, 2013. The primary endpoint was occurrence of a SHO, including liver cancer, liver failure, liver decompensation, or transplantation.Among the 16,365 patients newly diagnosed with schizophrenia between January 2002 and December 2013, we identified 614 patients with viral hepatitis and 1228 matched patients without viral hepatitis. Of these 1842 patients, 41 (2.22%) developed SHOs, including 26 (4.23%) in the viral hepatitis group and 15 (1.22%) in the control group, during the mean follow-up period of 3.71 ± 2.49 years. Cox proportional hazard analysis indicated that the SHO risk increased by 3.58 (95% confidence interval [CI]: 1.859-6.754; P < .001) in patients with schizophrenia and viral hepatitis. Moreover, patients with schizophrenia having HCV had a higher SHO risk than those without viral hepatitis (hazard ratio: 5.07, 95% CI: 1.612-15.956; P < .0001). Patients having both schizophrenia and viral hepatitis, especially HCV, had a higher risk of SHOs.

[Rhabdomyolysis induced by paliperidone palmitate]

Rhabdomyolysis is defined by disintegration of skeletal muscle fibres. Clinical presentation varies and is mostly associated with myalgias as well as elevation of creatine kinase in the serum. Mechanical damage, toxic medicinal factors, and predisposing factors such as myopathies may trigger the condition. This report describes a case of rhabdomyolysis uncovered by chance after administration of paliperidonepalmitate as depot medication in a 45 years old schizophrenic male patient after having tolerated oral risperidone without any problems. Routine screening for clinical manifestations and serum-creatin kinase maybe essential in unravelling antipsychotic-induced rhabdomyolysis.

Signals of Adverse Drug Reactions of Paliperidone Compared to Other Atypical Antipsychotics Using the Korean Adverse Event Reporting System Database

BACKGROUND AND OBJECTIVES

Schizophrenia is a severe public health problem and one of the top ten causes of disability, affecting about 1.1% of the world's population. Paliperidone is a new atypical antipsychotic used to treat schizophrenia. Several case reports about unexpected adverse drug reactions of paliperidone have been consistently reported around the world. The purpose of this study was to detect signals of adverse events (AEs) after paliperidone treatment using the Korea Institute of Drug Safety and Risk Management-Korea Adverse Event Reporting System database (KIDS-KD).

METHODS

We applied data-mining techniques based on a disproportionality analysis to KIDS-KD consisting of spontaneously reported AE reports related to atypical antipsychotics between January 2009 and December 2018. We calculated three data-mining indices of paliperidone compared to all other atypical antipsychotics. We defined signals that satisfied all three criteria of the indices. We checked if the signals identified were included in the drug labels for South Korea, the USA, the UK, Japan, Germany, and France.

RESULTS

The total number of suspected AE reports related to all atypical antipsychotics in the KIDS-KD from January 2009 to December 2018 was 43,970. Among those, the number of AE reports related to paliperidone was 9453. Overall, 13 signals such as seborrhea, hallucination, obesity, gingivitis, and intervertebral disorder were classified into newly detected meaningful signals.

CONCLUSION

We detected new AE signals of paliperidone that were not listed on the drug labels of six countries, and many that were related to psychotic symptoms, metabolic problems, and endocrine disorders.

Accidental Pediatric Paliperidone Ingestion Resulting in Delayed Profound Tachycardia

BACKGROUND

Paliperidone is an atypical antipsychotic that is approved to treat schizophrenia in patients 12 years of age and older. There are minimal data on the clinical effects of exposure in the < 12-year-old age group.

CASE REPORT

We report the case of a 7-year-old girl who was accidentally dosed with paliperidone for 3 days. Her clinical course was notable for a dystonic reaction and profound sinus tachycardia, with a heart rate peaking at 201 beats/min. The tachycardia persisted for over 64 h after her last dose. The mechanism of tachycardia has not been elucidated and is likely multifactorial, with alpha blockade and anticholinergic effects probably contributing. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Clinicians should be aware that paliperidone ingestion in children may result in delayed, profound tachycardia and may require more prolonged observation times or admission to the hospital.

Bayesian Meta-analysis of Multiple Continuous Treatments with Individual Participant-Level Data: An Application to Antipsychotic Drugs

Modeling dose-response relationships of drugs is essential to understanding their safety effects on patients under realistic circumstances. While intention-to-treat analyses of clinical trials provide the effect of assignment to a particular drug and dose, they do not capture observed exposure after factoring in nonadherence and dropout. We develop a Bayesian method to flexibly model the dose-response relationships of binary outcomes with continuous treatment, permitting multiple evidence sources, treatment effect heterogeneity, and nonlinear dose-response curves. In an application, we examine the risk of excessive weight gain for patients with schizophrenia treated with the second-generation antipsychotics paliperidone, risperidone, or olanzapine in 14 clinical trials. We define exposure as total cumulative dose (daily dose × duration) and convert to units equivalent to 100 mg of olanzapine (OLZ doses). Averaging over the sample population of 5891 subjects, the median dose ranged from 0 (placebo randomized participants) to 6.4 OLZ doses (paliperidone randomized participants). We found paliperidone to be least likely to cause excessive weight gain across a range of doses. Compared with 0 OLZ doses, at 5.0 OLZ doses, olanzapine subjects had a 15.6% (95% credible interval: 6.7, 27.1) excess risk of weight gain; corresponding estimates for paliperidone and risperidone were 3.2% (1.5, 5.2) and 14.9% (0.0, 38.7), respectively. Moreover, compared with nonblack participants, black participants had a 6.8% (1.0, 12.4) greater risk of excessive weight gain at 10.0 OLZ doses of paliperidone. Nevertheless, our findings suggest that paliperidone is safer in terms of weight gain risk than risperidone or olanzapine for all participants at low to moderate cumulative OLZ doses.

Serum Concentration of Paliperidone Palmitate Administered Every 3 Weeks

Schizophrenia, a disabling yet relatively common mental illness, is often controlled by antipsychotic drugs. However, long-term treatments are subject to non-adherence and consequent treatment failure. Non-adherence can be reduced by administration of slow-release drugs such as intramuscularly injected (IM) paliperidone palmitate. Considerable inter- and intra-individual variation in serum drug concentration exists, whose effect on clinical efficacy remains unclear. We report two cases of off-label use resulting in serum paliperidone levels greatly exceeding the recommended therapeutic window. A 20- and 31-year-old male were treated with 150 mg IM paliperidone palmitate/21 days. After one and two years, blood drug concentrations were 240 nmol/l and 610 nmol/l, respectively. Neither patient exhibited major adverse effects. Thus paliperidone serum levels greatly in excess of recommended targets can be well tolerated, although we urge caution with off-label use of paliperidone palmitate as it is not always the most appropriate way to achieve the control of schizophrenia.

Switching to paliperidone extended release in patients with schizophrenia dissatisfied with previous olanzapine treatment: Post hoc analysis of an open-label, prospective study

OBJECTIVE

This post hoc analysis of an open-label, single-arm, multicenter study was designed to assess the efficacy, safety, and tolerability of paliperidone extended release (ER) in Chinese patients with non-acute schizophrenia, after switching from olanzapine.

METHODS

Patients with schizophrenia who were dissatisfied with prior olanzapine treatment switched to flexible paliperidone ER (3-12 mg/day) based on clinical judgment. Change from baseline to week 12 in Positive and Negative Syndrome Scale (PANSS) total scores (primary endpoint), PANSS subscale scores, response rate, Clinical Global Impression-Severity (CGI-S) score, personal and social performance (PSP) scores, patient satisfaction with treatment score, change in sleep quality, level of daytime sleepiness and safety were evaluated.

RESULTS

Out of 118 enrolled patients, 95 (81%) completed the study. Mean duration of study was 76.9 (23.85) days. The primary endpoint, mean (SD) PANSS total score changed significantly from baseline to endpoint (-19.6 [18.71], P <.0001). Secondary endpoints including PANSS subscale score, PSP, patient satisfaction and daytime drowsiness also significantly improved (P <.001). Most commonly reported (≥1%) treatment-emergent adverse events were akathisia (n = 14 [12%]) and insomnia (n = 9 [8%]).

CONCLUSIONS

Switching to flexible-dosed paliperidone ER in patients dissatisfied with prior olanzapine treatment achieved good efficacy and tolerability consistently over 12 weeks.

Paliperidone Palmitate 3-Monthly Versus 1-Monthly Injectable in Patients With Schizophrenia With or Without Prior Exposure to Oral Risperidone or Paliperidone: A Post Hoc, Subgroup Analysis

BACKGROUND AND OBJECTIVE

Paliperidone palmitate 3-monthly (PP3M) injectable formulation offers an advantage of improved medication adherence and lower relapse risk in patients with schizophrenia. This post hoc analysis compared outcomes following PP3M versus paliperidone palmitate 1-monthly (PP1M) treatment in patients with schizophrenia treated/untreated with oral risperidone/paliperidone (RIS/PALI).

METHODS

Patients were treated with PP1M (50, 75, 100, or 150 mg equivalent [eq.]) for 17 weeks during an open-label (OL) phase and randomized (1:1) to PP3M (175, 263, 350, or 525 mg eq.) or PP1M (50, 75, 100, or 150 mg eq.) during a 48-week double-blind phase. Efficacy outcomes were compared based on prior oral RIS/PALI exposure: recent (≥ 28 days of oral RIS/PALI exposure with last dose within 14 days before study entry); or no (no oral RIS/PALI exposure within 60 days before study entry).

RESULTS

A total of 452 OL patients received recent oral RIS/PALI (n = 323 [71%], randomized to PP3M = 166; PP1M = 157), and 709 OL patients were without recent oral RIS/PALI (n = 506 [71%], randomized to PP3M = 254; PP1M = 252). Improvements in Positive and Negative Syndrome Scale (PANSS) scores (OL baseline-to-endpoint) were similar in recent-RIS/PALI (mean [standard deviation]:18.3 [17.96]) and no-RIS/PALI (- 21.1 [16.40]) subgroups. Relapse-free rates were comparable between recent-RIS/PALI (relapse-free rate [95% confidence interval for difference]: 2.6 [- 4.7 to 10.0]; PP3M: 90%; PP1M: 87%) and no-RIS/PALI subgroups (0.8 [- 4.5 to 6.0]; PP3M: 92%; PP1M: 91%). Weight gain was the most common (> 5% incidence) treatment-emergent adverse event in both subgroups irrespective of the prior treatment.

CONCLUSION

Patients with schizophrenia, irrespective of prior treatment with RIS/PALI, had comparable treatment outcomes and tolerability following PP3M or PP1M treatment.

REGISTRATION

This study is registered at the EU clinical trial registry (EudraCT Number: 2011-004889-15) and ClinicalTrials.gov (identifier: NCT01515423).

[The syndrome of inappropriate diuretic hormone secretion (SIADH) ending lethal during the use of paliperidon and lamotrigine]

Hyponatremia, as a result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH), is well known with the use of nearly all antipsychotics and mood stabilizers. The first symptoms are atypical and are not always mentioned by the patient. However, not recognising the syndrome in due time can be lethal. We describe a 35-year-old woman who died due to lack of recognition of SIADH. The patient, who had a bipolar disorder and was for a long time on a paliperidone depot, developed complaints of nausea, vomiting and thirst after lamotrigine was prescribed. A few days after increasing the dose, she died; no evidence was found of suicide. The SIADH was probably triggered by the use of lamotrigine and paliperidone. Paying sufficient attention to the symptoms that may cause this syndrome, as well as their early recognition, could save lives.

Aripiprazole Lauroxil Compared with Paliperidone Palmitate in Patients with Schizophrenia: An Indirect Treatment Comparison

BACKGROUND

Aripiprazole lauroxil (AL) is a long-acting injectable atypical antipsychotic recently approved for treatment of schizophrenia on the basis of a large-scale trial of two doses of AL versus placebo. There are no direct-comparison studies with paliperidone palmitate (PP; long-acting antipsychotic used most often in acute settings) for the acute psychotic episode.

OBJECTIVES

To indirectly compare efficacy and safety of the pivotal AL study with all PP studies meeting indirect comparison criteria.

METHODS

Systematic searches of MEDLINE, Embase, Cochrane CENTRAL, PsycINFO, ClinicalTrials.gov, International Clinical Trials Registry Platform, and gray literature were performed to identify randomized controlled trials of PP with similar designs to the AL trial. Bayesian network meta-analysis compared treatments with respect to symptom response and tolerability issues including weight gain, akathisia, parkinsonism, and likelihood of treatment-emergent adverse events.

RESULTS

Three appropriate PP studies were identified for indirect comparison. Both doses of AL (441 mg and 882 mg monthly) were used and compared with two efficacious doses of PP (156 mg and 234 mg monthly). All four active-treatment conditions were associated with comparable reductions in acute symptoms (Positive and Negative Syndrome Scale) versus placebo and were of similar magnitude (range of mean difference -8.12 to -12.01, with overlapping 95% credible intervals). Between-group comparisons of active-treatment arms were associated with summary estimates of magnitude near 0. No clinically meaningful differences in selected safety or tolerability parameter incidence were found between active treatments.

CONCLUSIONS

These results suggest that both AL and PP are effective for treatment of adults experiencing acute exacerbation of schizophrenia.

Health care resource utilization and costs of California Medicaid patients with schizophrenia treated with paliperidone palmitate once monthly or atypical oral antipsychotic treatment

OBJECTIVE

To compare all-cause health care utilization and costs between patients with schizophrenia treated with once monthly paliperidone palmitate (PP1M; Invega Sustenna ¹ ) and atypical oral antipsychotic therapy (OAT).

METHODS

This was a retrospective claims-based analysis among adult California Medicaid (Medi-Cal) patients with schizophrenia having ≥2 claims for PP1M or OAT from 1 July 2009 to 31 December 2013 and continuous health plan enrollment for ≥1 year pre- and post-index date (PP1M or OAT initiation date). Baseline characteristics were reported descriptively. Propensity score matching with a 1:1 greedy match method was used to create two matched cohorts. Treatment patterns, all-cause health care utilization, and costs for the 12 month follow-up period were compared between the two matched cohorts.

RESULTS

Two well matched cohorts of 722 patients were produced with similar baseline characteristics. During the 12 month follow-up period, PP1M patients were significantly less likely to discontinue treatment (30.6% vs. 39.5%, p < .001) or switch to a new therapy (21.6% vs. 27.7%, p = .007). PP1M patients had fewer inpatient visits (5.0 vs. 7.9, p < .001), lower mean hospitalization days (15.0 vs. 27.7 days, p < .001) and inpatient costs ($5060 vs. $10,880, p < .001). While pharmacy costs were significantly higher in the PP1M cohort ($16,347 vs. $9115, p < .001), total costs were not significantly different between the matched cohorts ($25,546 vs. $25,307, p = 0.853).

CONCLUSIONS

Patients with schizophrenia treated with PP1M had significantly fewer inpatient hospitalizations and associated costs with no significant difference in the total costs between the two cohorts. This study is subject to limitations associated with claims data such as miscoding, inability to examine clinical severity, etc.

Cost Effectiveness of Paliperidone Long-Acting Injectable Versus Other Antipsychotics for the Maintenance Treatment of Schizophrenia in France

BACKGROUND

French clinical recommendations suggest prescribing long-acting injectable (LAI) antipsychotics to patients with a maintenance treatment indication in schizophrenia. Despite this, and due to their relatively high acquisition and administration costs, LAIs are still underused in clinical practice in France, thus highlighting the need for pharmacoeconomic evaluations.

OBJECTIVE

Our objective was to estimate the cost effectiveness of paliperidone LAI (or paliperidone palmitate), a once-monthly second-generation LAI antipsychotic, compared with the most common antipsychotic medications for the maintenance treatment of schizophrenia in France.

METHODS

A Markov model was developed to simulate the progression of a cohort of schizophrenic patients through four health states (stable treated, stable non-treated, relapse and death) and to consider up to three lines of treatment to account for changes in treatment management. Paliperidone LAI was compared with risperidone LAI, aripiprazole LAI, olanzapine LAI, haloperidol LAI (or haloperidol decanoate) and oral olanzapine. Costs, quality-adjusted life-years (QALYs) and number of relapses were assessed over 5 years based on 3-month cycles with a discount rate of 4% and from a French health insurance perspective. Patients were considered to be stabilised after a schizophrenic episode and would enter the model at an initiation phase, followed by a prevention of relapse phase if successful. Data (e.g. relapse or discontinuation rates) for the initiation phase came from randomised clinical trials, whereas relapse rates in the prevention phase were derived from hospitalisation risks based on real-life French data to capture adherence effects. Safety and utility data were derived from international publications. Additionally, costs were retrieved from French health insurance databases and publications. Finally, expert opinion was used for validation purposes or in case of gaps in data. The robustness of results was assessed through deterministic and probabilistic sensitivity analyses.

RESULTS

All LAI antipsychotics were found to have similar costs over 5 years: approximatively €55,000, except for paliperidone LAI which had a discounted cost of €50,880. Oral olanzapine was less costly than LAIs (i.e. €50,379 after 5 years) but was associated with fewer QALYs gained and relapses avoided. Paliperidone LAI dominated aripiprazole LAI, olanzapine LAI and haloperidol LAI in terms of costs per QALY, and it was associated with slightly fewer QALYs when compared with risperidone LAI (i.e. 3.763 vs 3.764). This resulted in a high incremental cost-effectiveness ratio (ICER) (i.e. €4,770,018 per QALY gained) for risperidone LAI compared with paliperidone LAI. Paliperidone LAI was more costly than olanzapine oral but associated with more QALYs (i.e. ICER of €2411 per QALY gained for paliperidone LAI compared with oral olanzapine). Paliperidone LAI had a probability of being the optimal strategy in more than 50% of cases for a willingness-to-pay threshold of €8000 per QALY gained.

CONCLUSION

This analysis, to the best of our knowledge, is the first of its kind to assess the cost effectiveness of antipsychotics based on French observational data. Paliperidone LAI appeared to be a cost-effective option in the treatment of schizophrenia from the French health insurance perspective.

A Case Report of Probable Paliperidone ER-Induced Serotonin Syndrome in a 17-Year-Old Taiwanese Female With New Onset Psychosis

A 17-year-old female with new-onset psychosis was treated with paliperidone. After increasing the paliperidone dose to 12 mg per day the patient developed a series of side effects; Tachycardia (140 bpm), severe drooling, restlessness, diaphoresis, whole-body tremor, inducible foot clonus, predominant lower limbs rigidity, bilateral pupil dilation, increased bowel sounds with watery diarrhea, and muscle hypertonicity. The symptoms subsided after stopping the paliperidone, and recurred after resuming paliperidone 9 mg per day. To our knowledge, this is the first case of a very clear and close relationship between the symptoms of serotonin syndrome and the use of paliperidone. We have to cautiously consider the diagnosis of serotonin syndrome in potential cases.

Efficacy and Safety of Paliperidone Palmitate 3-Month Formulation for Patients with Schizophrenia: A Randomized, Multicenter, Double-Blind, Noninferiority Study

BACKGROUND

This double-blind, parallel-group, multicenter, phase-3 study was designed to test the noninferiority of paliperidone palmitate 3-month formulation (PP3M) to the currently marketed 1-month formulation (PP1M) in patients (age 18-70 years) with schizophrenia, previously stabilized on PP1M.

METHODS

After screening (≤3 weeks) and a 17-week, flexible-dosed, open-label phase (PP1M: day 1 [150mg eq. deltoid], day 8 [100mg eq. deltoid.], weeks 5, 9, and 13 [50, 75, 100, or 150mg eq., deltoid/gluteal]), clinically stable patients were randomized (1:1) to PP3M (fixed-dose, 175, 263, 350, or 525mg eq. deltoid/gluteal) or PP1M (fixed-dose, 50, 75, 100, or 150mg eq. deltoid/gluteal) for a 48-week double-blind phase.

RESULTS

Overall, 1016/1429 open-label patients entered the double-blind phase (PP3M: n=504; PP1M: n=512) and 842 completed it (including patients with relapse). PP3M was noninferior to PP1M: relapse rates were similar in both groups (PP3M: n=37, 8%; PP1M: n=45, 9%; difference in relapse-free rate: 1.2% [95% CI:-2.7%; 5.1%]) based on Kaplan-Meier estimates (primary efficacy). Secondary endpoint results (changes from double-blind baseline in positive and negative symptom score total and subscale scores, Clinical Global Impression-Severity, and Personal and Social Performance scores) were consistent with primary endpoint results. No clinically relevant differences were observed in pharmacokinetic exposures between PP3M and PP1M. Both groups had similar tolerability profiles; increased weight was the most common treatment-emergent adverse event (double-blind phase; 21% each). No new safety signals were detected.

CONCLUSION

Taken together, PP3M with its 3-month dosing interval is a unique option for relapse prevention in schizophrenia.

Simultaneous Use of Intravenous Lipid Emulsion and Plasma Exchange Therapies in Multiple Drug Toxicity

OBJECTIVE

The aim of this study was to highlight the use of combined intravenous lipid emulsion (ILE) and plasma exchange (PE) therapies in multidrug toxicity.

CLINICAL PRESENTATION AND INTERVENTION

A 45-year-old woman who attempted suicide by ingesting large quantities of amisulpride (28 g), diazepam (250 mg), valsartan (2,240 mg), aripiprazole (45 mg) and paliperidone (21 mg) was taken to the hospital of Adnan Menderes University School of Medicine. Upon arrival, she exhibited signs of cardiotoxicity and severe depression of the central nervous and respiratory systems. She was treated successfully with ILE for 4 h and PE therapy for 36 h, consecutively. She was discharged on the fourth day of hospitalization having fully recovered.

CONCLUSION

The patient was successfully treated with the combination of ILE and PE.

Cost effectiveness of paliperidone palmitate versus oral antipsychotics in patients with schizophrenia and a history of criminal justice involvement

OBJECTIVE

Conduct a cost effectiveness analysis for the Paliperidone palmitate Research In Demonstrating Effectiveness (PRIDE) trial.

RESEARCH DESIGN AND METHODS

PRIDE was a 15 month, prospective, randomized, open-label study in which once monthly paliperidone palmitate significantly delayed the time to first treatment failure (healthcare or criminal justice system [HC/CJS] events) versus oral antipsychotics in recently incarcerated adults with schizophrenia. The present analysis used a state government perspective and HC/CJS event data that were collected on a resource use questionnaire (RUQ) every 3 months.

MAIN OUTCOME MEASURES

Since cost information was not collected in the trial, cost estimates from published literature and an analysis of multistate Medicaid data for CJS and HC events, respectively, were applied to RUQ event data. Effectiveness and costs were adjusted to 456 days (trial duration). Incremental cost effectiveness was calculated as the adjusted cost difference divided by the adjusted effectiveness difference.

RESULTS

Adjusted costs (in US dollars) in the paliperidone palmitate group (n = 198) and the oral antipsychotic group (n = 193), respectively, were: non-drug costs $22,331 and $25,027; drug costs $18,592 and $7833; and total costs $40,923 and $32,860. Adjusted effectiveness differences and corresponding incremental cost effectiveness per event avoided (in parentheses) for paliperidone palmitate versus oral antipsychotics were as follows: 0.33 fewer CJS events ($24,409), 0.13 fewer psychiatric hospitalizations ($60,484), 0.46 fewer psychiatric hospitalizations or CJS events combined ($17,391), and 0.30 fewer incarcerations ($26,754).

CONCLUSIONS

Costs for HC/CJS events avoided offset 25% of the greater drug cost for the paliperidone palmitate versus oral antipsychotic treatment group in this vulnerable population. Use of a recall-dependent RUQ for event rates and cost estimates instead of actual costs are potential limitations and may make the results conservative from a state government perspective. Indirect costs are likely to be substantial for this population, but were not considered in the analysis.

Estimated medical cost reductions for paliperidone palmitate vs placebo in a randomized, double-blind relapse-prevention trial of patients with schizoaffective disorder

OBJECTIVE

The objective of this economic model was to estimate the difference in medical costs among patients treated with paliperidone palmitate once-monthly injectable antipsychotic (PP1M) vs placebo, based on clinical event rates reported in the 15-month randomized, double-blind, placebo-controlled, parallel-group study of paliperidone palmitate evaluating time to relapse in subjects with schizoaffective disorder.

RESEARCH DESIGN AND METHODS

Rates of psychotic, depressive, and/or manic relapses and serious and non-serious treatment-emergent adverse events (TEAEs) were obtained from the long-term paliperidone palmitate vs placebo relapse prevention study. The total annual medical cost for a relapse from a US payer perspective was obtained from published literature and the costs for serious and non-serious TEAEs were based on Common Procedure Terminology codes. Total annual medical cost differences for patients treated with PP1M vs placebo were then estimated. Additionally, one-way and Monte Carlo sensitivity analyses were conducted.

RESULTS

Lower rates of relapse (-18.3%) and serious TEAEs (-3.9%) were associated with use of PP1M vs placebo as reported in the long-term paliperidone palmitate vs placebo relapse prevention study. As a result of the reduction in these clinical event rates, the total annual medical cost was reduced by $7140 per patient treated with PP1M vs placebo. One-way sensitivity analysis showed that variations in relapse rates had the greatest impact on the estimated medical cost differences (range: -$9786, -$4670). Of the 10,000 random cycles of Monte Carlo simulations, 100% showed a medical cost difference <$0 (reduction) for patients using PPIM vs placebo. The average total annual medical differences per patient were -$8321 for PP1M monotherapy and -$6031 for PPIM adjunctive therapy.

CONCLUSIONS

Use of PP1M for treatment of patients with schizoaffective disorder was associated with a significantly lower rate of relapse and a reduction in medical costs compared to placebo. Further evaluation in the real-world setting is warranted.

Incidence of tardive dyskinesia: a comparison of long-acting injectable and oral paliperidone clinical trial databases

BACKGROUND

To assess the tardive dyskinesia (TD) rate in studies of once-monthly long-acting injectable (LAI) paliperidone palmitate (PP) and once-daily oral paliperidone extended release (Pali ER).

METHODS

Completed schizophrenia and bipolar studies for PP and Pali ER (≥ 6 month duration with retrievable patient-level data) were included in this post hoc analysis. Schooler-Kane research criteria were applied using Abnormal Involuntary Movement Scale (AIMS) scores to categorise probable (qualifying AIMS scores persisting for ≥ 3 months) and persistent TD (score persisting ≥ 6 months). Spontaneously reported TD adverse events (AEs) were also summarised. Impact of exposure duration on dyskinesia (defined as AIMS total score ≥ 3) was assessed by summarising the monthly dyskinesia rate.

RESULTS

In the schizophrenia studies, TD rates for PP (four studies, N = 1689) vs. Pali ER (five studies, N = 2054), were: spontaneously reported AE, 0.18% (PP) vs. 0.10% (Pali ER); probable TD, 0.12% (PP) vs. 0.19% (Pali ER) and persistent TD, 0.12% (PP) vs. 0.05% (Pali ER). In the only bipolar study identified [Pali ER (N = 614)], TD rate was zero (spontaneously reported AE reporting, probable and persistent TD assessments). Dyskinesia rate was higher within the first month of treatment with both PP (13.1%) and Pali ER (11.7%) and steadily decreased over time (months 6-7: PP: 5.4%; Pali ER: 6.4%). Mean exposure: PP, 279.6 days; Pali ER, 187.2 days.

CONCLUSIONS

Risk of TD with paliperidone was low (< 0.2%), regardless of the formulation (oral or LAI), in this clinical trial dataset. Longer cumulative exposure does not appear to increase the risk of dyskinesias.