Pharmacokinetics and efficacy of a direct switch from conventional depot to risperidone long-acting injection in Chinese patients with schizophrenic and schizoaffective disorders

Therapeutic Drug Monitoring of Paliperidone in Patients With Schizophrenia in Taiwan

BACKGROUND

The blood level of antipsychotics affects clinical responses to the drug; it can be influenced by race and several individual factors. This study analyzed the therapeutic plasma concentrations (Cps) of paliperidone for both oral and long-acting injectable (LAI) formulations in clinical samples from Taiwanese patients.

METHODS

Patients diagnosed with schizophrenia and treated with either oral paliperidone for at least 4 weeks or LAI paliperidone for at least 6 months were enrolled. Blood samples were taken before the morning dose of oral paliperidone or the injection of LAI paliperidone to obtain the trough Cps.

RESULTS

Among the patients in this study, 51 were taking oral paliperidone, and 26 were receiving LAI paliperidone. In the oral group, the mean Cps were 40.2 ± 19.8 ng/mL in patients taking 9 mg/d and 44.2 ± 15.9 ng/mL in those taking 12 mg/d. In the LAI group, the mean Cps were 32.9 ± 12.7 ng/mL in patients receiving 100 mg per 28 days and 49.9 ± 25.9 ng/mL in those receiving 150 mg per 28 days. The mean Cps per daily dose (Cps/DD) were 4.11 ± 1.99 ng/mL/mg in the oral group and 9.24 ± 3.78 ng/mL/mg in the LAI group.

CONCLUSIONS

Under the suggested DD for oral and LAI paliperidone treatment, most Taiwanese patients with schizophrenia can reach the suggested therapeutic Cps range. Wide interindividual differences were observed in the Cps/DD for both the oral (7-fold) and LAI paliperidone (4-fold) groups. Compared with Western reports, no difference was observed in the body weight-adjusted Cps/DD.

The Relation between the Plasma Concentrations of Long-Acting Atypical Antipsychotics and Clinical Effectiveness in Patients Affected by Schizophrenia or Schizoaffective Disorder: A Comprehensive Overview

Atypical antipsychotic depot medications are currently recommended for patients with schizophrenia (SCZ) to prevent relapse and ameliorate the long-term prognosis of these patients. This review critically summarizes the available data about the association between the plasma concentrations of long-acting Second- Generation Antipsychotics (SGAs) and the clinical effectiveness of these compounds in patients affected by SCZ or schizoaffective disorder. Our question is if the measurement of these concentrations can be helpful for clinicians in predicting treatment response and clinical stabilization of patients. Bibliographic research on the main databases was performed, and 13 studies were finally included in this review. Contrasting results were found between plasma concentrations of long-acting injectable (LAI) risperidone and clinical amelioration according to rating scale scores. Data are too scanty to draw conclusions for olanzapine and paliperidone. In contrast, despite small sample sizes, data are quite concordant in showing a relation between long-acting SGA plasma concentrations and D2 receptor occupancy. Despite the preliminary encouraging results, particularly for D2 receptor occupancy, future research with larger samples will have to confirm the clinical usefulness of measuring LAI SGA plasma concentrations to predict the clinical response of patients affected by severe mental conditions such as SCZ.

Does Switching Antipsychotics Ameliorate Weight Gain in Patients With Severe Mental Illness? A Systematic Review and Meta-analysis

OBJECTIVE

Obesity and adverse metabolic outcomes in patients with severe mental illness are clinically significant but potentially preventable. Importantly, the evidence for switching to antipsychotics to reduce cardiometabolic burden is unclear.

METHOD

PubMED, Embase, PsycINFO, and Cochrane were searched from inception to March 8, 2020. Articles reporting weight and metabolic changes after antipsychotic switching vs staying on the previous antipsychotic were meta-analyzed both across and within group.

RESULTS

Of 61 identified studies, 59 were meta-analyzed (40% rated high quality). In the switch-vs-stay pairwise meta-analyses, only aripiprazole significantly reduced weight (-5.52 kg, 95% CI -10.63, -0.42, P = .03), while olanzapine significantly increased weight (2.46 kg, 95% CI 0.34, 4.57, P = .02). Switching to aripiprazole also significantly improved fasting glucose (-3.99 mg/dl, 95% CI -7.34, -0.64, P = .02) and triglycerides (-31.03 mg/dl, 95% CI -48.73, -13.34, P = .0001). Dropout and psychosis ratings did not differ between switch and stay groups for aripiprazole and olanzapine. In before-to-after switch meta-analyses, aripiprazole (-1.96 kg, 95% CI -3.07, -0.85, P < .001) and ziprasidone (-2.22 kg, 95% CI -3.84, -0.60, P = .007) were associated with weight loss, whereas olanzapine (2.71 kg, 95% CI 1.87, 3.55, P < .001), and clozapine (2.80 kg, 95% CI 0.26, 5.34, P = .03) were associated with weight gain. No significant weight or other cardiometabolic changes were observed when switching to amisulpride, paliperidone/risperidone, quetiapine, or lurasidone.

CONCLUSIONS

Switching antipsychotics to agents with lower weight gain potential, notably to aripiprazole and ziprasidone, can improve weight profile and other cardiometabolic outcomes. When choosing switch agents, both the weight gain potential of the pre- and post-switch antipsychotic must be considered. Antipsychotic switching in psychiatrically stable patients must be weighed against the risk of psychiatric worsening.

Therapeutic Drug Monitoring of Long-Acting Injectable Antipsychotic Drugs

BACKGROUND

The use of therapeutic drug monitoring (TDM) to guide treatment with long-acting injectable (LAI) antipsychotics, which are increasingly prescribed, remains a matter of debate. The aim of this review was to provide a practical framework for the integration of TDM when switching from an oral formulation to the LAI counterpart, and in maintenance treatment.

METHODS

The authors critically reviewed 3 types of data: (1) positron emission tomography data evaluating dopamine (D2/D3) receptor occupancy related to antipsychotic concentrations in serum or plasma; D2/D3 receptors are embraced as target sites in the brain for antipsychotic efficacy and tolerability, (2) pharmacokinetic studies evaluating the switch from oral to LAI antipsychotics, and (3) pharmacokinetic data for LAI formulations. Based on these data, indications for TDM and therapeutic reference ranges were considered for LAI antipsychotics.

RESULTS

Antipsychotic concentrations in blood exhibited interindividual variability not only under oral but also under LAI formulations because these concentrations are affected by demographic characteristics such as age and sex, genetic peculiarities, and clinical variables, including comedications and comorbidities. Reported data combined with positron emission tomography evidence indicated a trend toward lower concentrations under LAI administration than under oral medications. However, the available evidence is insufficient to recommend LAI-specific therapeutic reference ranges.

CONCLUSIONS

Although TDM evidence for newer LAI formulations is limited, this review suggests the use of TDM when switching an antipsychotic from oral to its LAI formulation. The application of TDM practice is more accurate for dose selection than the use of dose equivalents as it accounts more precisely for individual characteristics.

Cross-sectional comparison of first-generation antipsychotic long-acting injections vs risperidone long-acting injection: patient-rated attitudes, satisfaction and tolerability

OBJECTIVES

The objective of this study was to compare patients' attitudes and satisfaction with medication and patient-rated tolerability between those prescribed a first-generation antipsychotic long-acting injection (FGA-LAI) and those prescribed risperidone long-acting injection (RLAI).

METHOD

A cross-sectional study of a representative sample of outpatients prescribed an FGA-LAI or RLAI for a minimum of 6 months and attending a depot clinic. Attitudes to medication were assessed by the Drug Attitude Inventory (DAI-30), tolerability was measured by the Liverpool University Neuroleptic Side Effect Rating Scale (LUNSERS) and satisfaction with antipsychotic medication was assessed by the Satisfaction with Antipsychotic Medication (SWAM) scale.

RESULTS

The RLAI (n = 28) and FGA-LAI (n = 39) groups did not differ in terms of mean age, sex, diagnosis and ethnicity. All individual LAIs were prescribed within British National Formulary limits. The most commonly prescribed FGA-LAI was flupentixol decanoate (n = 22). There was no significant difference between the RLAI and FGA-LAI groups in terms of mean total scores on the DAI-30, LUNSERS and SWAM or the tolerability subscales of the LUNSERS or the two subscales (treatment acceptability and medication insight) of the SWAM. In both LAI groups there was a low level of side effects (LUNSERS) and a generally positive attitude (DAI-30) and reasonable satisfaction (SWAM) with medication.

CONCLUSIONS

Patients treated with FGA-LAI and RLAI for at least 6 months did not differ in terms of patient-rated tolerability, attitudes and satisfaction with medication. The current design cannot determine whether differences would have been evident earlier on during treatment. These results should be regarded as preliminary and are subject to prescribing bias. Randomized studies avoid prescribing bias and are a superior way to compare specific LAIs. Ideally randomized studies should include patient-rated outcome measures including medication tolerability; assessment of side effects, efficacy and quality of life made by blinded raters; and additional objective side-effect data including changes in weight and key blood parameters.

The role of long-acting injectable antipsychotics in schizophrenia: a critical appraisal

Despite their widespread use, long-acting injectable (LAI) antipsychotics (APs) are often regarded with some negativity because of the assumption of punishment, control and insufficient evolution towards psychosocial development of patients. However, LAI APs have proved effective in schizophrenia and other severe psychotic disorders because they assure stable blood levels, leading to a reduction of the risk of relapse. Therapeutic opportunities have also arisen after introduction of newer, second-generation LAI APs in recent years. Newer LAI APs are more readily dosed optimally, may be better tolerated and are better suited to integrated rehabilitation programmes. This review outlines the older and newer LAI APs available for the treatment of schizophrenia, with considerations of past and present pharmacological and therapeutic issues. Traditional, evidence-based approaches to systematic reviews and randomized clinical trials are of limited utility in this area so this paper's blending of experimental trials with observational research is particularly appropriate and effective.

The prevalence of metabolic syndrome in Korean patients with schizophrenia receiving a monotherapy with aripiprazole, olanzapine or risperidone

Second-generation antipsychotics (SGAs) increase the risk of metabolic syndrome (MetS). Although ethnicity also contributes to MetS risk, the majority of the studies on the relationship of SGAs to this syndrome come from Western countries, whereas few reports have come from Asian countries, especially regarding patients taking a single SGA. We reviewed the electronic medical records of patients with schizophrenia who received aripiprazole, olanzapine or risperidone monotherapies for at least three months. We evaluated the prevalence of MetS in our sample as well as the indirect standardized prevalence ratio (ISPR) using data from the 4th Korean National Health and Nutrition Examination Survey (KNHNES, 2007). The prevalence of MetS in our sample (n=145) was 31.7%, and the ISPR was 2.09. Male patients had a higher prevalence of MetS than female patients (odds ratio [OR]=4.18, 95% CI=1.93-9.03). The ISPR of male patients was 2.67 and statistically significant, whereas the ISPR of female patients was not significant. In our sample, the frequency of abnormal MetS subcomponents occurred in descending order: increased waist circumference, increased triglyceride levels, decreased HDL-cholesterol levels, elevated blood pressure and elevated fasting blood glucose levels. Patients who received aripiprazole were significantly less likely to have MetS. However, a logistic regression showed that age and sex, but not the type of antipsychotic, its dose or the use of antidepressants, were significantly related to the presence of MetS. There were no statistically significant differences among SGAs in terms of MetS subcomponent abnormalities of after adjusting for age and sex. In conclusion, only male Korean patients with schizophrenia who received a monotherapy of aripiprazole, olanzapine or risperidone for more than three months were more likely to have MetS than the general population.