Paliperidone 3-Month Injection for Treatment of Schizophrenia: A Narrative Review

Cumulative Clinical Experience of the Use of Paliperidone Palmitate 3-Monthly Long-Acting Injection in the Treatment of Schizophrenia: A Critical Appraisal

Paliperidone palmitate 3-monthly (PP3M), an approved maintenance treatment for patients with schizophrenia, was the first long-acting antipsychotic injectable (LAI) to require only four administrations per year. Here, we aimed to review the available evidence about its use in the management of schizophrenia to date and highlight key study findings in order to provide a balanced overview of current experience in clinical practice. For that purpose, an extensive search of available literature from PubMed, Embase, and Web of Science was conducted in March 2023. Emerging data from real-world studies appear to signal that the benefits of the use of PP3M may well extent beyond the obvious convenience for patients and resource efficiency for services and may be actually associated with improved effectiveness and patient satisfaction. Large naturalistic studies from Australia, Europe and the US comparing treatment continuation between newer LAIs and/or oral antipsychotics showed that patients treated with PP3M had higher compliance rates and a longer period of continuous use. The risk of relapse, re-hospitalization and number of bed days was also lower with PP3M compared to PP1M and other LAIs as demonstrated by several cohort studies. Furthermore, patients treated with PP3M were using lower doses of benzodiazepines and concomitant oral antipsychotics compared with other LAIs. What is more, PP3M appears to positively impact patients' satisfaction and quality of life, facilitating long-term goals. In fact, recent studies recorded better quality-adjusted life years and decreased stigma, with improved social acceptability and promotion of rehabilitation for patients transitioning to PP3M. The rates of general satisfaction rates with PP3M were also higher among psychiatrists and caregivers who reported overall less concerns. In conclusion, clinical exposure and a growing body of evidence thus far, reinforce the use of PP3M in an effort to enhance patient outcomes alongside individual experience and treatment persistence.

Rebound Catatonia Associated With Injectable Paliperidone

Paliperidone is an atypical antipsychotic medication commonly used to treat schizophrenia, schizoaffective disorder, and bipolar disorder. It is a metabolite of risperidone and has a similar mechanism of action, primarily blocking dopamine 2 receptors (D2 receptors) in the brain. Paliperidone has various adverse effects, including extrapyramidal symptoms, weight gain, and metabolic disturbances. Catatonia is rare but severe side effects can occur in the context of an underlying psychiatric, neurologic, or general medical condition. Paradoxically, antipsychotics for treating schizophrenia or bipolar spectrum disorders can precipitate or worsen catatonic symptoms. The report suggests that 17-19% of all cases diagnosed as catatonia due to other medical conditions are medication-induced. Catatonia is a neuropsychiatric syndrome that presents as a cluster of psychomotor signs and symptoms resulting in movement and behavior aberrations. Various symptoms, including mutism, stupor, rigidity, and abnormal movements, characterize catatonia. Catatonia is a potentially life-threatening condition requiring prompt recognition and management. Here, we present a case of a patient with catatonia associated with long-acting injectable paliperidone intramuscular therapy in a patient with schizophrenia.

Comparing Relapse Rates in Real-World Patients with Schizophrenia Who Were Adequately versus Not Adequately Treated with Paliperidone Palmitate Once-Monthly Injections Before Transitioning to Once-Every-3-Months Injections

Purpose

This retrospective cohort study evaluated real-world data on relapses in adult patients with schizophrenia who transitioned to long-acting injectable paliperidone palmitate once-every-3-months (PP3M) following treatment with once-monthly paliperidone palmitate (PP1M).

Patients and Methods

Data derived from the IBM® MarketScan® Multi-State Medicaid Database were analyzed. Adults aged ≥18 years with ≥1 schizophrenia diagnosis claim and ≥12 months of continuous medical and prescription enrollment before and/or at index date of PP3M were eligible for inclusion. Patients were matched on propensity score to 2 PP3M cohorts: (1) adequately treated (AT), defined as patients treated with PP1M for ≥4 months, with the last 2 doses the same and a PP3M initiation dose meeting the corresponding PP1M-to-PP3M dose conversion, or (2) not adequately treated (NAT), defined as patients who received ≤2 or no PP1M doses. Relapse rates and time to relapse distributions based on the first occurrence of a qualifying event during the 2-year follow-up period were compared between PP3M cohorts using Kaplan-Meier survival curves and log rank test statistics. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. Two sensitivity analyses using different matched populations were performed to assess the robustness of the primary findings.

Results

Propensity score matching yielded a sample of 1314 patients (657 per group). Most patients were male (68.9%) and aged 25-64 years (90.1%). The relapse rate was significantly lower in the AT (18.4%) versus NAT cohort (26.8%), P = 0.0002. Risk of relapse decreased by 35% for AT versus NAT (HR: 0.65 [95% CI: 0.51-0.81]). Relapse reductions favored the AT cohort in both sensitivity analyses (HR: 0.67 [95% CI: 0.54-0.83] and HR: 0.74 [95% CI: 0.56-0.97]).

Conclusion

In this analysis of Medicaid claims data, patients adequately treated with PP1M before transitioning to PP3M demonstrated significantly lower relapse rates and delayed time to relapse.

A 10-year mirror-image study of effectiveness and cost of long-acting paliperidone palmitate injectable in patients with schizophrenia or schizoaffective disorder

Acute episodes of Schizophrenia and Schizoaffective Disorder often require hospitalizations and/or psychiatry emergency room (PER) visits, with significant economic burden. Long-acting injectables (LAI), such as the once-monthly Palmitate Paliperidone LAI (1MPP) are effective in suppressing symptoms and raise treatment adherence. This study is the first aimed at evaluating long-term efficacy of initiation of 1MPP. This was a mirror-image study with a total 10 year observational length. Sample was divided into five different groups according to time span of observation: 2,4,6,8, and 10 years. Number of participants per group was 162, 129, 95, 77 and 35, respectively. Main outcomes were number and length of hospitalizations and number of PER visit. Significant reductions in these outcomes after initiation of 1MPP were found in all groups. Subgroups consisting only of patients with full adherence were evaluated, and these had better outcomes. A cost evaluation was also performed, which demonstrated decreases every year, for all main outcomes. Sensitivity analysis in the 2-year group showed results in this time-frame are independent of gender, diagnosis, previous LAI or 1MPP initiation setting. Initiation of 1MPP reduces number and length of hospitalizations up to 5 years, decreasing associated costs. This study increases evidence supporting use of 1MPP in patients with Schizophrenia or Schizoaffective disorder.