Pharmacokinetic drug evaluation of paliperidone in the treatment of schizoaffective disorder

In vivo deposition of poorly soluble drugs

Administered drug molecules, whether dissolved or solubilized, have the potential to precipitate and accumulate as solid forms in tissues and cells within the body. This phase transition can significantly impact the pharmacokinetics of treatment. It is thus crucial to gain an understanding of how drug solubility/permeability, drug formulations and routes of administration affect in vivo behaviors of drug deposition. This review examines literature reports on the drug deposition in tissues and cells of poorly water-soluble drugs, as well as underlying physical mechanisms that lead to precipitation. Our work particularly highlights drug deposition in macrophages and the subcellular fate of precipitated drugs. We also propose a tissue permeability-based classification framework to evaluate precipitation potentials of poorly soluble drugs in major organs and tissues. The impact on pharmacokinetics is further discussed and needs to be considered in developing drug delivery systems. Finally, bioimaging techniques that are used to examine aggregated states and the intracellular trafficking of absorbed drugs are summarized.

Analysis of the status of drug treatment in 746 inpatients with early-onset schizophrenia in China: a retrospective study

BACKGROUND

There is limited evidence on the use of antipsychotics in patients with early-onset schizophrenia, which lags significantly behind the studies on adult patients' medication and has a large disparity from actual clinical needs. Hence, this study aims to analyse the status of the drug use and its changes for patients with early-onset schizophrenia in our ward and to provide references on clinical medications for children and adolescents with schizophrenia.

METHODS

The distribution of antipsychotics on the day of discharge and their changes over time were retrospectively analysed in our inpatient department from March 2012 to July 2019. Descriptive statistical methods and χ2 tests were carried out.

RESULTS

A total of 746 inpatients with early-onset schizophrenia were included. Among them, 99.3% of patients were prescribed atypical antipsychotic drugs, with 5.5% of patients prescribed typical antipsychotic drugs. The top five most commonly used antipsychotics were aripiprazole, olanzapine, risperidone, paliperidone and clozapine. Olanzapine and risperidone were used more frequently in men (P < 0.01), whereas aripiprazole was used less frequently (P < 0.01). Olanzapine and paliperidone were used more frequently in patients with adolescent-onset schizophrenia (AOS) (P < 0.05), and risperidone was used more frequently in patients with child-onset schizophrenia (COS) (P < 0.01). Multiple antipsychotics during hospitalization were prescribed in 23.1% of patients. The combination of aripiprazole and olanzapine was the most common in the AOS group, and the combination of risperidone and clozapine was the most common in the COS group. Before and after approval by the competent Chinese authorities, the use of paliperidone and aripiprazole tended to be stable.

CONCLUSION

Atypical antipsychotics have been increasingly valued and used clinically. The consideration of medications for patients with early-onset schizophrenia needs to include factors such as age, sex, and severity of illness, metabolism and cognitive function at baseline.

Dose-Corrected Serum Concentrations and Metabolite to Parent Compound Ratios of Venlafaxine and Risperidone from Childhood to Old Age

OBJECTIVE

Comparative pharmacokinetic data about the antidepressant venlafaxine (VEN) and the antipsychotic drug risperidone (RIS) over the lifespan and especially in children and adolescents is lacking. This is the first cross-sectional study that aimed to investigate differences in dose-corrected serum concentrations (CDs) and metabolite to parent compound ratios (MPRs) of VEN and RIS across the lifespan.

METHODS

Patients treated with VEN and RIS at the University Hospital of Würzburg, Germany were included in the study. Serum level determinations were performed during clinical routine care. Patients with CYP2D6 influencing co-medication were excluded from analyses.

RESULTS

In 953 patients (12-93 years) treated with VEN and 552 patients (7-92 years) treated with RIS, children/adolescents (<18 years) showed 11% and 19%, and 44% and 42% lower CDs of the active moieties (CDs_AM) of VEN and RIS than adults and elderly (≥60 years) (Kruskal-Wallis tests; p ≤ 0.001). However, when CDs were normalized to body weight, a different pattern emerged. Gender differences, with higher CDs_AM in females were present in adults and elderlies but not in children/adolescents. No gender- or age-dependent difference in MPRs was found; however, 80% of MPRs of RIS in children/adolescents were below the range of "normal" CYP2D6 function for adults.

CONCLUSIONS

We suggest a higher clearance as a reason for lower CDs_AM of VEN and RIS in children/adolescents compared to adults/elderlies. Metabolism of VEN or RIS by CYP2D6, characterized by MPRs, was not associated with age. However, MPRs of RIS were lower in children/adolescents, possibly due to a higher renal clearance of 9-OH-risperidone.

Evaluation of paliperidone on social function in patients with chronic schizophrenia

BACKGROUND

The impairment of social function is widespread in the patients with chronic schizophrenia, which seriously affects family, life and work conditions.

AIMS

The main purpose of this study was to investigate the efficacy of paliperidone in the treatment of social function in chronic schizophrenia.

METHODS

A total of 81 patients who met the standard criteria for schizophrenia and long-term hospitalised inpatients were randomly divided into the treatment group and normal control group following a 1- year prospective follow-up study. The reatment group (41 cases) used paliperidone extended-release tablets for reducing dosage, as appropriate, based on the original treatment strategy; and the control group (40 cases) used the former drugs. All patients were assessed using the Positive and Negative Symptom Scales (PANSS), and the Treatment Emergent Symptom Scale (TESS) was used to assess adverse drug reactions. The Hospitalised Psychiatric Patients' Social Functions Rating Scale (SSPI) was used to assess social function of participants before and after 8  weeks, 6  months and 1 year of treatment.

RESULTS

At baseline there were no significant differences between the two groups in age, duration of illness, educational background and dosage of antipsychotic drugs (converted into chlorpromazine equivalency). There was statistically significant difference in PANSS positive symptoms by interaction effect (F_group×time=18.24, df=3237, p<0.001) and time effect (F_time=21.66, df=3, p<0.01) and the difference in PANSS positive symptoms by grouping effect (F_group=0.68, df=1, p=0.41) was not statistically significant. The difference of grouping effect of PANSS negative symptoms (F_group=9.93, df=1, p=0.002), time effect (F_time=279.15, df=3, p<0.001) and interaction effect (F_{group × time}=279.15, df=3237, p<0.001) were statistically significant. There were statistically significant differences in the grouping effect (F_{gr oup}=6.59, df=1, p=0.012), time effect (F_time=152.97, df=3, p<0.001) and interaction effect (F_{group × time}=148.82, df=3237, p<0.001) of PANSS general pathological symptoms, the same as the total score of the PANSS, which showed large differences in grouping effect (F_{g roup}=7.04, df=1, p=0.001), time effect (F_time=210.78, df=3, p<0.001) and interaction effect (F_{group × time}=205.20, df=3237, p<0.01). We found in the total SSPI score, grouping effect (F_group=31.70, df=1, p<0.001), time effect (F_time=161.84, df=3, p<0.001) and interaction effect (F_{group × time}=132.74, df=3237, p<0.001) were demonstrated to be significantly different. Even though adverse reactions occurred 7 times in the treatment group and 44 times in the control group based on the Treatment Emergent Symptom Scale (TESS), incidence rate was significantly lower than that of the control group (χ²=18.854, p<0.001).

CONCLUSION

Paliperidone can safely and effectively improve negative symptoms and social function in patients with chronic schizophrenia.