A critical appraisal of paliperidone long-acting injection in the treatment of schizoaffective disorder

Prodrug approaches for the development of a long-acting drug delivery systems

Long-acting formulations are designed to reduce dosing frequency and simplify dosing schedules by providing an extended duration of action. One approach to obtain long-acting formulations is to combine long-acting prodrugs (LA-prodrug) with existing or emerging drug delivery technologies (DDS). The design criteria for long-acting prodrugs are distinct from conventional prodrug strategies that alter absorption, distribution, metabolism, and excretion (ADME) parameters. Our review focuses on long-acting prodrug delivery systems (LA-prodrug DDS), which is a subcategory of long-acting formulations where prodrug design enables DDS formulation to achieve an extended duration of action that is greater than the parent drug. Here, we define LA-prodrugs as the conjugation of an active pharmaceutical ingredient (API) to a promoiety group via a cleavable covalent linker, where both the promoiety and linker are selected to enable formulation and administration from a drug delivery system (DDS) to achieve an extended duration of action. These LA-prodrug DDS results in an extended interval where the API is within a therapeutic range without necessarily altering ADME as is typical of conventional prodrugs. The conversion of the LA-prodrug to the API is dependent on linker cleavage, which can occur before or after release from the DDS. The requirement for linker cleavage provides an additional tool to prolong release from these LA-prodrug DDS. In addition, the physicochemical properties of drugs can be tuned by promoiety selection for a particular DDS. Conjugation with promoieties that are carriers or amenable to assembly into carriers can also provide access to formulations designed for extending duration of action. LA-prodrugs have been applied to a wide variety of drug delivery strategies and are categorized in this review by promoiety size and complexity. Small molecule promoieties (typically MW < 1000 Da) have been used to improve encapsulation or partitioning as well as broaden APIs for use with traditional long-acting formulations such as solid drug dispersions. Macromolecular promoieties (typically MW > 1000 Da) have been applied to hydrogels, nanoparticles, micelles, dendrimers, and polymerized prodrug monomers. The resulting LA-prodrug DDS enable extended duration of action for active pharmaceuticals across a wide range of applications, with target release timescales spanning days to years.

Impact of initiating long-acting injectable paliperidone palmitate on relapse and hospitalization in patients with bipolar I disorder: A mirror image retrospective study

Literature assessing the use of long-acting injectable paliperidone palmitate in patients with bipolar I disorder is limited. The aim of this retrospective study was to determine the effectiveness of long-acting injectable paliperidone palmitate treatment on relapse and hospitalization in a real-world setting. Patients with bipolar I disorder aged 18-65 years, who were treated with paliperidone palmitate once-monthly (PP1M) for at least one year, were included. The rate of relapse, hospitalization, and length of hospital stay were collected. Safety outcomes included levels of prolactin, fasting blood sugar, total cholesterol, triglyceride, high density lipoprotein, and low density lipoprotein. The data of 36 patients who met the study criteria were evaluated. Number and length of hospitalizations, number of manic and mixed episodes significantly decreased after PP1M addition. When we compared the prolactin, fasting blood sugar, total cholesterol, triglyceride, high density lipoprotein, and low density lipoprotein levels as an indicator of the safety of treatment, there was no statistically significant change in these values before and after PP1M addition. Our findings suggested PP1M may be effective in reducing manic and mixed episodes. Limitations include a mirror image retrospective design and small sample size.

Recent advances in long-acting nanoformulations for delivery of antiretroviral drugs

In spite of introduction of combination antiretroviral therapy (cART) against human immunodeficiency virus (HIV) infection; inaccessibility and poor adherence to oral cART costs 10 in 100,000 death worldwide. Failure in adherence leads to viral rebound, emergence of drug resistance and anticipated HIV infection in high risk individuals. Various Long-acting antiretroviral (LA ARV) nanoformulations including nano-prodrug, solid drug nanoparticles (SDN), nanocrystals, aspherical nanoparticles, polymeric and lipidic nanoparticles have shown plasma/tissue drug concentration in the therapeutic range for several weeks during pre-clinical evaluation. LA ARV nanoformulations therefore have replaced cART as better alternative for the treatment of HIV infection. Cabenuva™ is recently approved by Health Canada containing LA cabotegravir+LA rilpivirine nanocrystals (ViiV healthcare) for once monthly administration by intramuscular route. The LA nanoformulation due to its nanosize insist on better stability, delivery to lymphatic, slow release into systemic circulation via lymphatic-circulatory system conjoint and secondary drug depot within infiltered immune cells at site of administration and systemic circulation in contrast to conventional drugs. However, the pharmacokinetic, biodistribution and efficacy of LA nanoformulations hinge onto physicochemical properties of the drugs and route of administration. Therefore, current review emphasizes on these contradistinctive factors that affects the reproducibility, safety, efficacy and toxicity of LA anti-HIV nanoformulations. Moreover, it expatiates on application of profuse nanoformulations for long-acting effect with promising preclinical discoveries and two clinical leads. To add on, utilization of physiology-based and mechanism-based pharmacokinetic modelling and in vivo animal models which could lead to enhanced safety and efficacy of LA ARV nanoformulations in humans have been included.

The modern perspective for long-acting injectables antipsychotics in the patient-centered care of schizophrenia

Schizophrenia is a chronic syndrome involving different clinical dimensions, and causes significant disability with a negative impact on the quality of life of patients and their caregivers. Current guidelines for the treatment of schizophrenia focus on maximizing a patient's adaptive functioning and quality of life in a recovery-oriented approach that encourages active collaboration among patients, caregivers, and mental health professionals to design and manage a customized and comprehensive care plan. In the present study, a panel of experts (psychiatrists, psychologists, nurse, and social worker) gathered to review and explore the need for contemporary use of second-generation antipsychotic long-acting injectables (SGA LAIs) in "recovery-oriented" and "patient-centered" care of schizophrenia. Starting from the available data and from sharing personal attitudes and experiences, the panel selected three clinical dimensions considered useful in characterizing each patient: phase of disease, adherence to treatment, and level of functioning. For each clinical dimension, perspectives of patients and caregivers with regard to needs, expectations, and personal experiences were reviewed and the role of SGA LAIs in achieving shared goals examined. The experts concluded that from today's modern perspectives, SGA-LAIs may play an important role in breaking the spiral of desocialization and functional decline in schizophrenia, thus favoring the recovery process.

Clinical improvement, relapse and treatment adherence with paliperidone palmitate 1-month formulation: 1-year treatment in a naturalistic outpatient setting

PURPOSE

To evaluate paliperidone palmitate 1-month formulation (PP1M) effectiveness in a naturalistic outpatient psychiatric setting.

MATERIALS AND METHODS

We collected data from 50 outpatients affected by schizophrenia disorders treated with PP1M for 12 months in an Italian Mental Health Department. After analyzing selected demographic, clinical and pharmacological variables, we performed mirror analysis to compare psychiatric hospitalizations and urgent consultations required by the same patient 6 and 12 months before and after PP1M implementation (primary outcome). We analyzed clinical improvement in symptom (Clinical Global Impression-severity and improvement) and functioning (Global Assessment of Functioning) scales and drop-out rate during the 12-month PP1M treatment (secondary outcome). Data were statistically analyzed.

RESULTS

The mean PP1M dose was 93.5 mg (±27.7 SD) with a mean interval between each injection of 27.1 d (±4.5 SD). Twenty-three patients (46%) reported adverse effects (sexual dysfunctions, weight gain and extrapyramidal symptoms).Fifteen patients (30%) dropped out after 137.2 d (±103.1 SD) on average: six due to the lack of therapeutic adherence, six due to inefficacy and three due to adverse events. The drop-out patients presented more severe clinical profile in CGI-S and GAF scores at T0 in comparison with others. At mirror analysis, 12-month but not 6-month PP1M treatment statistically significantly reduced psychiatric hospitalizations (t = 2.3, p < .05) and urgent consultations (t = 2.1, p < .05). Both scale scores showed statistically significant improvement at T12 in comparison to T0.

CONCLUSIONS

This naturalistic study indicates that long-term PP1M treatment was safe and effective in preventing hospitalizations and urgent consultations as well as in improving clinical course.

A 6-Month Prospective Trial of a Personalized Behavioral Intervention + Long-Acting Injectable Antipsychotic in Individuals With Schizophrenia at Risk of Treatment Nonadherence and Homelessness

PURPOSE

Long-acting injectable antipsychotics (LAI) can optimize adherence for high-risk serious mental illness (SMI). This customized adherence-enhancement approach delivered by social worker interventionists was combined with LAI (CAE-L) of paliperidone palmitate for homeless, poorly adherent individuals with SMI.

METHODS

This 6-month prospective, uncontrolled trial of CAE-L in 30 recently homeless individuals with SMI assessed adherence using the Tablets Routine Questionnaire, injection frequency, and SMI symptoms measured by the Positive and Negative Syndrome Scale, Brief Psychiatric Rating Scale, and Clinical Global Impressions. The Social and Occupational Functioning Assessment Scale measured social function. Standardized scales assessed extrapyramidal effects.

FINDINGS

Patients' mean age was 43.6 (SD, 9.53) years, and they were mainly minorities (86.7% African American) and single/never married (72.4%). Rate of substance abuse within the past year was 40.0%, and rate of incarceration within the past 6 months was 32.1%. Four participants (13.3%) terminated the study prematurely. Customized adherence enhancement + LAI was associated with good adherence to LAI (92.9%) and improved adherence with oral drug as measured by Tablets Routine Questionnaire (P = 0.02). There were significant improvements in Positive and Negative Syndrome Scale (P < 0.01), Brief Psychiatric Rating Scale (P < 0.001), Clinical Global Impressions (P = 0.003), and Social and Occupational Functioning Assessment Scale (P = 0.005). There were no significant extrapyramidal effects.

IMPLICATIONS

While findings must be tempered by the methodological limitations, CAE-L seems associated with multiple domains of improvement in homeless/recently homeless individuals with SMI. Adverse effects limit tolerability in some individuals, and not all will remain engaged. However, LAI combined with a patient-centered behavioral approach can improve outcomes for some high-risk individuals with SMI.

Mixed States in Bipolar Disorder: Etiology, Pathogenesis and Treatment

Many bipolar disorder patients exhibit mixed affective states, which portend a generally more severe illness course and treatment resistance. In the previous renditions of Diagnostic and Statistical Manual mixed states were narrowly defined in the context of bipolar I disorder, but with the advent of DSM-5 the term “mixed episode” was dropped and replaced by “mixed features” specifier which could be broadly applied to manic, hypomanic and depressive episodes in both the bipolar spectrum and major depressive disorders. This paradigm shift reflected their significance in the prognosis and overall management of mood disorders, so that the clinicians should thoroughly familiarize themselves with the contemporary notions surrounding these conditions. The purpose of this manuscript is to bring to light the current conceptualizations regarding the etiology, pathogenesis and treatment of mixed states. To achieve this goal, in June 2016 an extensive literature search was undertaken using the PubMed database. Some exploratory terms utilized included “mixed states”, “mixed episodes”, “switching”, “rapid cycling” cross referenced with “bipolar disorder”. Focusing on the most relevant and up to date studies, it was revealed that mixed states result from genetic susceptibility in the circadian and dopamine neurotransmission apparatuses and disturbance in the intricate catecholamine-acetylcholine neurotransmission balance which leads to mood fluctuations. The management of mixed states is challenging with atypical antipsychotics, newer anticonvulsants and electroconvulsive therapy emerging as the foremost treatment options. In conclusion, while progress has been made in the neurobiological understanding of mixed states, the currently available therapeutic modalities have only shown limited effectiveness.