Switching from risperidone long-acting injectable to paliperidone long-acting injectable or oral antipsychotics: analysis of a Medicaid claims database

Comparing the pharmacology and pharmacokinetics of antipsychotics: Choosing an antipsychotic and dosing a long-acting injectable

In this paper, we will discuss the pharmacologic properties of antipsychotics, including those that are the same in structure and those that differentiate one from another. We will bring to you how differential pharmacologic properties can explain differential efficacy and differential tolerability. We will review how to use plasma drug levels and long-acting injectables to enhance compliance early in the illness, and to manage both forms of treatment resistance (pharmacokinetic and pharmacodynamic failures). Through inadequate pharmacokinetic processes (poor absorption, rapid metabolism, enzymatic polymorphisms, etc.), antipsychotic plasma levels do not reach sufficient concentration. Pharmacodynamic treatment failure (receptor binding and sensitivity, post-receptor effects, etc.) is the inability to provide a significant effect on psychotic symptoms despite therapeutic plasma levels. Long-Acting Injectable (LAI) antipsychotics employ technology that can provide a useful treatment tool in the armamentarium of a modern psychopharmacologist. The pharmacologic properties of antipsychotics differentiate one from another and can help explain differences in efficacy and tolerability. Utilizing plasma drug levels can enhance understanding of treatment failures and lead to specific patient management strategies for best outcomes. This kind of personalized approach to antipsychotic dosage would mean a big shift in the treatment of psychiatric patients.

Smart design of patient centric long-acting products: from preclinical to marketed pipeline trends and opportunities

INTRODUCTION

We see a development in the field of long-acting products to serve patients with chronic diseases by providing benefits in adherence, efficacy and safety of the treatment. This review investigates features of long-acting products on the market/pipeline to understand which drug substance (DS) and drug product (DP) characteristics likely enable a successful patient-centric, low-dosing frequency product.

AREAS COVERED

This review evaluates marketed/pipeline long-acting products with greater than one week release of small molecules and peptides by oral and injectable route of administration (RoA), with particular focus on patient centricity, adherence impact, health outcomes, market trends, and the match of DS/DP technologies which lead to market success.

EXPERT OPINION

Emerging trends are expected to change the field of long-acting products in the upcoming years by increasing capability in engineered molecules (low solubility, long half-life, high potency, etc.), directly developing DP as long-acting oral/injectable, increasing the proportion of products for local drug delivery, and a direction towards more subcutaneous, self-administered products. Among long-acting injectable products, nanosuspensions show a superiority in dose per administration and dosing interval, overwhelming the field of infectious diseases with the recently marketed products.

Impact of schizophrenia relapse definition on the comparative effectiveness of oral versus injectable antipsychotics: A systematic review and meta-analysis of observational studies

Although relapse is an important outcome to measure the effectiveness of schizophrenia treatment, no standard definition exists. This review aimed at identifying definitions and measurements of schizophrenia relapse in observational studies of long‐acting injectables (LAIs) versus oral antipsychotics (OAPs) and at determining their impact on heterogeneity of comparative effectiveness estimates. A systematic review was conducted using MEDLINE and Embase (01 January 2010–11 November 2019 [date last searched]). Pragmatic searches of gray literature and snowballing were also conducted. Search outputs were screened independently by two assessors at first stage, and full‐text of potentially eligible sources at second stage. For each retained source, definition and measurement of relapse, study methods, and comparative effectiveness estimates were extracted. Heterogeneity of estimates was assessed using I² statistic with a threshold of 50% for substantial heterogeneity. Literature search yielded 543 sources and pragmatic searches, 21, of which 35 were eligible. Twelve definitions of relapse were found based on hospitalization/emergency department (ED) data (28 studies) or clinical assessment (5 studies). No definition was provided in five studies. According to quantitative analyses, in studies defining relapse as schizophrenia‐related hospitalization and/or ED visits over 1‐year follow‐up, LAIs were significantly more effective than OAPs. For studies measuring relapse based on all‐cause hospitalization, heterogeneity was too high for pooling; yet this definition is the most frequently found in pooled estimates published in the literature. Schizophrenia relapse definitions led to substantial heterogeneity of comparative effectiveness estimates of LAIs versus OAPs. Creating study subgroups based on relapse definition effectively reduces statistical heterogeneity.

Long-acting injectable versus oral antipsychotics for the maintenance treatment of schizophrenia: a systematic review and comparative meta-analysis of randomised, cohort, and pre-post studies

BACKGROUND

Evidence of comparative benefits of long-acting injectable antipsychotics (LAIs) versus oral antipsychotics for schizophrenia has been inconsistent across study designs. The aim of this study was to evaluate the comparative benefits of LAIs versus oral antipsychotics in three study designs to inform clinical decision making.

METHODS

We did a comprehensive systematic review and meta-analysis comparing LAIs versus oral antipsychotics for schizophrenia covering three study designs: randomised controlled trials (RCTs), cohort studies, and pre-post studies. Our literature search was without language restrictions, in MEDLINE and PubMed, the Cochrane Library, Scopus, and Embase, for studies published from database inception up to a last search on March 13, 2020. We also searched for unpublished studies and ClinicalTrials.gov. We included studies lasting at least 6 months that targeted adults with schizophrenia and related disorders (>80% of participants). Studies on penfluridol (neither an LAI or daily oral antipsychotic), case reports, and case series with fewer than 20 patients were excluded. Two investigators independently extracted study-level data and resolved disagreement by consensus, or via a third investigator. Study authors were contacted to obtain additional information as needed. For our primary outcome we meta-analysed the risk ratio (RR) for hospitalisation or relapse with LAIs versus oral antipsychotics by a random-effects model, with hospitalisation used preferentially over relapse. As secondary analyses, we reversed the preferential order to relapse over hospitalisation, and assessed hospitalisation risk and relapse risk individually. Other secondary outcomes included all meta-analysable data, classed by relevance to effectiveness, efficacy, safety, quality of life, cognitive function, and other outcomes, and analysed by study design. Dichotomous outcomes were expressed as pooled RR and continuous outcomes as standardised mean difference (SMD). The protocol is registered with PROSPERO (CRD42019142094).

FINDINGS

We identified 14 687 records, of which 137 studies (397 319 patients) met the inclusion criteria (32 RCTs [23·4%; 8577 patients], 65 cohort studies [47·4%; 377 447 patients], and 40 pre-post studies [29·2%; 11 295 patients]) and were analysed. The quality of studies in terms of risk of bias varied across study designs and within each study design from low to high. LAIs were associated with a lower risk of hospitalisation or relapse than oral antipsychotics in each of the three study designs (RCTs: 29 studies, 7833 patients, RR 0·88 [95% CI 0·79-0·99], p=0·033; cohort studies: 44 studies, 106 136 patients, RR 0·92 [0·88-0·98], p=0·0044; pre-post studies: 28 studies, 17 876 patients, RR 0·44 [0·39-0·51], p<0·0001). This association was maintained across the study designs when we reversed the preferential order to risk of relapse over hospitalisation, and in individual analysis of hospitalisation risk. The association was maintained only in pre-post studies for relapse risk alone. In all other outcomes related to effectiveness, efficacy, safety, quality of life, cognitive function, and other outcomes, LAIs were more beneficial than oral antipsychotics in 60 (18·3%) of 328 comparisons, not different in 252 (76·8%) comparisons, and less beneficial in 16 (4·9%) comparisons when analysed by study design. Significant heterogeneity was observed across all three study designs. Publication biases were apparent in cohort and pre-post studies, but effect sizes were similar after trim-and-fill analyses.

INTERPRETATION

Although study designs have strengths and weaknesses, including potential low quality of observational studies, we consistently identified significant benefit with LAIs versus oral antipsychotics in preventing hospitalisation or relapse, in settings ranging from restricted research (RCTs) to real-word application (cohort and pre-post studies). Our findings suggest that increased clinical use of LAIs could improve outcomes in schizophrenia.

FUNDING

None.

TRANSLATIONS

For the Chinese, French, German, Italian, Japanese, Portugese and Spanish translations of the abstract see Supplementary Materials section.

Epidemiology of schizophrenia and its management over 8-years period using real-world data in Spain

BACKGROUND

Real-World Data (RWD) studies provide important insights in disease epidemiology, in real clinical populations, with long follow-up periods. The aim of the present study was to describe the epidemiology of schizophrenia spectrum disorders (SD) during an 8-year period in Spain.

METHODS

A retrospective cohort of subjects aged 15 to 64 years was followed-up using electronic healthcare databases of the Valencia region (2008-2015). SD cases included outpatient and inpatient settings (ICD 9 codes 295.XX). Prevalence of SD was assessed. Incidence rate (IR) in the subpopulation aged between 15 and 34 years was also provided. Healthcare utilization (HCU) rates, including outpatient, specialists, hospitalizations and antipsychotic dispensations were estimated.

RESULTS

The cohort included 3,976,071 subjects; 24,749 of them had a prevalent diagnosis of SD. The overall prevalence for SD was 6.2 per 1000 persons. SD were 76% more prevalent in men than women. IR in the subpopulation aged between 15 and 34 years was 50.25 per 100,000 persons years and was more than 2 times higher for men than for women. 83.4% of the overall outpatient visits from the cohort of patients were related to SD. The 21,095 overall hospitalizations with the SD code resulted in 286,139 days of hospitalization, with a median of 4 days (IQR: 1.6-9.2) per person-year. 93.2% of subjects diagnosed with SD were ever treated with some antipsychotic drug during the study period, and 70% of the patients were ever treated with antipsychotic polypharmacy.

CONCLUSIONS

This large population-based study using RWD provides novel and recent information SD in a southern European country. The prevalence and IR of SD showed is greater than previously published and higher in men than in women. The fact of having used a large arsenal of electronic data (including outpatient and inpatient) for 8 years may have influenced. SD represents high burden and healthcare utilization. Contrary to guidelines recommendations the majority of patients were ever treated with antipsychotic polypharmacy.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.

Is paliperidone palmitate more effective than other long-acting injectable antipsychotics?

BACKGROUND

Paliperidone palmitate is one of the most widely prescribed long-acting injectable (LAI) antipsychotics in the UK. However, it is relatively expensive and there are few data comparing its effectiveness to that of other LAI antipsychotics. We sought to address this issue by analyzing a large anonymized electronic health record (EHR) dataset from patients treated with LAI antipsychotics.

METHODS

EHR data were obtained from 1281 patients in the South London and Maudsley NHS Foundation Trust (SLaM) who started treatment with a LAI antipsychotic between 1 April 2011 and 31 January 2015. The number of days spent as a psychiatric inpatient and the number of admissions to a psychiatric hospital were analyzed in each of the 3 years before and after LAI prescription.

RESULTS

Patients treated with paliperidone palmitate (n = 430; 33.6%) had a greater number of inpatient days and a greater number of admissions in the year prior to treatment than those treated with other LAI antipsychotics. Nevertheless, in the 3 years after initiation there were no significant differences between paliperidone and the other LAI antipsychotics in the number of days as an inpatient (B coefficient 5.4 days, 95% confidence interval (CI) -57.3 to 68.2, p = 0.86) or number of hospital admissions (Incidence rate ratio 1.07, 95% CI 0.62 to 1.83, p = 0.82).

CONCLUSION

Paliperidone palmitate was more likely to be prescribed in patients with more frequent and lengthy hospital admissions prior to initiation. However, the absence of differences in outcomes after initiation indicates that paliperidone palmitate was not more effective than other cheaper LAI antipsychotics.

What is the risk-benefit ratio of long-term antipsychotic treatment in people with schizophrenia?

The long-term benefit-to-risk ratio of sustained antipsychotic treatment for schizophrenia has recently been questioned. In this paper, we critically examine the literature on the long-term efficacy and effectiveness of this treatment. We also review the evidence on the undesired effects, the impact on physical morbidity and mortality, as well as the neurobiological correlates of chronic exposure to antipsychotics. Finally, we summarize factors that affect the risk-benefit ratio. There is consistent evidence supporting the efficacy of antipsychotics in the short term and mid term following stabilization of acute psychotic symptoms. There is insufficient evidence supporting the notion that this effect changes in the long term. Most, but not all, of the long-term cohort studies find a decrease in efficacy during chronic treatment with antipsychotics. However, these results are inconclusive, given the extensive risk of bias, including increasing non-adherence. On the other hand, long-term studies based on national registries, which have lower risk of bias, find an advantage in terms of effectiveness during sustained antipsychotic treatment. Sustained antipsychotic treatment has been also consistently associated with lower mortality in people with schizophrenia compared to no antipsychotic treatment. Nevertheless, chronic antipsychotic use is associated with metabolic disturbance and tardive dyskinesia. The latter is the clearest undesired clinical consequence of brain functioning as a potential result of chronic antipsychotic exposure, likely from dopaminergic hypersensitivity, without otherwise clear evidence of other irreversible neurobiological changes. Adjunctive psychosocial interventions seem critical for achieving recovery. However, overall, the current literature does not support the safe reduction of antipsychotic dosages by 50% or more in stabilized individuals receiving adjunctive psychosocial interventions. In conclusion, the critical appraisal of the literature indicates that, although chronic antipsychotic use can be associated with undesirable neurologic and metabolic side effects, the evidence supporting its long-term efficacy and effectiveness, including impact on life expectancy, outweighs the evidence against this practice, overall indicating a favorable benefit-to-risk ratio. However, the finding that a minority of individuals diagnosed initially with schizophrenia appear to be relapse free for long periods, despite absence of sustained antipsychotic treatment, calls for further research on patient-level predictors of positive outcomes in people with an initial psychotic presentation.

Studies on drug switchability showed heterogeneity in methodological approaches: a scoping review

BACKGROUND AND OBJECTIVE

Several drugs share the same therapeutic indication, including those undergoing patent expiration. Concerns on the interchangeability are frequent in clinical practice, challenging the evaluation of switchability through observational research. The objective of this study was to conduct a scoping review of observational studies on drug switchability to identify methodological strategies adopted to deal with bias and confounding.

METHODS

We searched PubMed, EMBASE, and Web of Science (updated January 31, 2017) to identify studies evaluating switchability in terms of effectiveness/safety outcomes or compliance. Three reviewers independently screened studies extracting all characteristics. Strategies to address confounding, particularly previous drug use and switching reasons, were considered. All findings were summarized in descriptive analyses.

RESULTS

Thirty-two studies, published in the last 10 years, met the inclusion criteria. Epilepsy, cardiovascular, and rheumatology were the most frequently represented clinical areas. Seventy-five percent of the studies reported data on effectiveness/safety outcomes. The most frequent study design was cohort (65.6%) followed by case-control (21.9%) and self-controlled (12.5%). Case-control and case-crossover studies showed homogeneous methodological strategies to deal with bias and confounding. Among cohort studies, the confounding associated with previous drug use was addressed introducing variables in multivariate model (47.3%) or selecting only adherent patients (14.3%). Around 30% of cohort studies did not report reasons for switching. In the remaining 70%, clinical parameters or previous occurrence of outcomes was measured to identify switching connected with lack of effectiveness or adverse events.

CONCLUSION

This study represents a starting point for researchers and administrators who are approaching the investigation and assessment of issues related to interchangeability of drugs.

Effectiveness of Long-Acting Injectable vs Oral Antipsychotics in Patients With Schizophrenia: A Meta-analysis of Prospective and Retrospective Cohort Studies

Compared with oral antipsychotics (OAPs), long-acting injectable antipsychotics (LAIs) should improve medication adherence and reduce relapses in schizophrenia. However, meta-analyses of randomized trials and mirror-image studies yielded inconsistent results. Nonrandomized cohort studies with parallel comparisons of LAIs and OAPs offer a third design to examine this issue. We meta-analyzed cohort studies with ≥24 weeks duration and hospitalization data. Primary outcome was hospitalization rate, ie, number of hospitalizations per person-year. Secondary outcomes included hospitalization risk, ie, proportion of patients experiencing ≥1 hospitalizations, all-cause discontinuation, and total hospitalization days. Patient severity and/or chronicity at baseline was also meta-analyzed and explored as a potential effect size moderator. Altogether, 42 studies (n = 101 624; follow-up = 18.6 ± 10.0 mo) were meta-analyzed. LAIs were superior to OAPs regarding hospitalization rate (studies = 15, person-years = 68 009, rate ratio = 0.85, 95% CI = 0.78-0.93, P < .001) and all-cause discontinuations (studies = 10, n = 37 293, risk ratio = 0.78, 95% CI = 0.67-0.91, P = .001), but not regarding hospitalization risk (studies = 33, n = 51 733, risk ratio = 0.92, 95% CI = 0.84-1.00, P = .06), and hospitalization days (studies = 11, n = 21 328, Hedges' g = -0.05, 95% CI = -0.16 to 0.06, P = .39). Illness severity/chronicity was significantly greater in patients prescribed LAIs vs OAPs when all available information was pooled together (studies = 23, n = 61 806, Hedges' g = 0.15, 95% CI = 0.03-0.26, P = .01), but not when examined separately. In summary, this meta-analysis of cohort studies, which included patients that are broadly representative of clinical practice, indicates that LAIs are superior to OAPs. The lack of significant superiority of LAIs for hospitalization risk and hospital days needs to be interpreted in the context of naturalistic treatment selection with subsequently greater illness severity/chronicity in LAI-treated patients.

Real-world data on paliperidone palmitate for the treatment of schizophrenia and other psychotic disorders: a systematic review of randomized and nonrandomized studies

The aim of this study was to perform a systematic review of the effects of 1-month paliperidone palmitate (PP1M) for the treatment of schizophrenia and related psychotic disorders in terms of outcomes reported in real-world evidence studies. A systematic review of real-world randomized and nonrandomized studies with PP1M was performed and is reported according to PRISMA guidelines. Comparative effectiveness data with oral antipsychotics indicate that PP1M has a lower likelihood of relapse-related events, including rehospitalization, and these differences are clinically relevant. A randomized, double-blind study showed that PP1M has no advantage over haloperidol decanoate in the time to treatment failure. Although there was a marked variability across studies, PP1M was not superior to other antipsychotics in terms of study completion rates. Pharmacoeconomic data show that, during a follow-up period of 12 months, the mean total healthcare cost was not significantly different in patients treated with PP1M compared with those receiving oral antipsychotics. The mean maximum prolactin levels were significantly higher with PP1M than with haloperidol decanoate; however, neither drug differs in the frequency of prolactin-related adverse events. Results on prolactin-related adverse events were inconsistent in two randomized comparisons with oral antipsychotics and were not reported in a randomized comparison with aripiprazole. There were no significant differences between haloperidol decanoate and PP1M in the severity of abnormal involuntary movements and parkinsonism, or in the incidence of tardive dyskinesia; however, patients treated with haloperidol decanoate showed greater worsening of akathisia and required treatment for parkinsonism and akathisia significantly more frequently than patients who received PP1M. In conclusion, real-world data that originate from both pragmatic randomized clinical trials and observational studies indicate that PP1M is superior to oral antipsychotics in delaying the time to relapse or treatment failure. Furthermore, the pharmacoeconomic data reviewed for this article suggest that the advantages of PP1M compared with oral antipsychotics are not associated with an increased total cost for healthcare providers.

Efficacy and safety profile of paliperidone palmitate injections in the management of patients with schizophrenia: an evidence-based review

The course of schizophrenia is characterized by multiple relapses, incomplete remission of symptoms, enduring cognitive deficits, and social and occupational functional impairments. Nonadherence to antipsychotic medication is a major determinant of this poor outcome. Long-acting injectable antipsychotics were developed specifically to address the nonadherence problem and are increasingly considered as an early treatment option, in an attempt to prevent accruing morbidity. This review focuses on paliperidone palmitate, the long-acting injectable (LAI) formulation of paliperidone. After considering the pharmacology of paliperidone palmitate, we review the randomized controlled trials, as well as pertinent observational, pragmatic studies for paliperidone once-monthly injections in schizophrenia. Finally, we review the recently introduced 3-monthly formulation of paliperidone palmitate. Taken together, the studies indicate that paliperidone palmitate (PP) has good efficacy compared with placebo and comparable with other antipsychotics including risperidone. The tolerability profile of PP is similar to that of risperidone, with the most important side effects being prolactin elevation, weight gain, and extrapyramidal symptoms. Advantages of PP include the extensive research database and clinical experience with paliperidone and its parent compound risperidone, the availability of different LAI formulations (once-monthly, 3-monthly, and perhaps even longer acting formulations in future), and the novel dose initiation procedure that provides rapid onset of action without the need for oral antipsychotic supplementation.

Effects of Discontinuation of Paliperidone Long-Acting Injectable After Switching from Risperidone Long-Acting Injectable Switching

BACKGROUND

Risperidone long-acting injection (RLAI) is increasingly being switched to paliperidone palmitate (PP) because of several benefits. However, this switching is not always successful.

METHODS

We examined patient profiles following discontinuation of PP after switching from RLAI. We collected the electronic records of 24 patients with schizophrenia who had switched from RLAI to PP treatment at our hospital between November 2013 and March 2014. Twelve patients continued PP injection for over 1 year (PP-continuers), the other 12 patients discontinued within 1 year (PP-discontinuers), and both groups were followed up until December 31, 2014.

RESULTS

PP-discontinuers had significantly shorter RLAI-administration period (mean 73.1 ± 59.0 weeks versus 148.5 ± 75.0 weeks), and lower chlorpromazine (CP) equivalent mean doses (mean 553.5 ± 251.0 mg versus 1002.5 ± 529.3 mg) compared with PP-continuers. The CP equivalent mean dose of PP-discontinuers had increased at the time of discontinuation and their social status became significantly worse. Six PP-discontinuers (50%) re-switched to RLAI, and their social status was not significantly worse at the end of the observation period.

CONCLUSIONS

On switching from RLAI to PP, we need to consider that some patients have had a shorter RLAI-administration period and may require lower amounts of antipsychotics.