Impact of age and gender on paliperidone exposure in patients after administration of long-acting injectable formulations-an observational study using blood samples from 1223 patients

The European psychiatric association (EPA) - early career psychiatrists committee survey on trainees' and early-career psychiatrists' attitudes towards therapeutic drug monitoring (TDM) use and utility during antipsychotic treatment

OBJECTIVES

This survey assessed psychiatry residents'/early-career psychiatrists' attitudes towards the utility of therapeutic drug monitoring (TDM) of antipsychotics.

METHODS

A previously developed questionnaire on attitudes on TDM utility during antipsychotic treatment was cross-sectionally disseminated by national coordinators between 01/01/2022-31/12/2023. The frequency of using TDM for antipsychotics other than clozapine was the main outcome in a linear regression analysis, including sex, clinical setting, caseload, and factors generated by an exploratory factor analysis. Comparisons between residents and early-career psychiatrists, respondents working in in- and outpatient settings, and low-/middle- and high-income countries were performed.

RESULTS

Altogether, 1,237 respondents completed the survey, with 37.9% having never used TDM for antipsychotics. Seven factors explained 41% of response variance; six of them were associated with frequency of TDM use (p < 0.05). Items with highest loadings for factors included clinical benefits of TDM (factors A and E: 0.7), negative expectations for beliefs of patients towards TDM (factor B: 0.6-0.7), weak TDM scientific evidence (factor C: 0.8), and TDM availability (factor D: -0.8). Respondents from low-/middle-income countries were less likely to frequently/almost always use TDM compared to high-income countries (9.4% vs. 21.5%, p < 0.001).

DISCUSSION

TDM use for antipsychotics was poor and associated with limited knowledge and insufficient availability.

Evidence-Based Recommendations for the Pharmacological Treatment of Women with Schizophrenia Spectrum Disorders

PURPOSE OF REVIEW

Despite clear evidence that sex differences largely impact the efficacy and tolerability of antipsychotic medication, current treatment guidelines for schizophrenia spectrum disorders (SSD) do not differentiate between men and women. This review summarizes the available evidence on strategies that may improve pharmacotherapy for women and provides evidence-based recommendations to optimize treatment for women with schizophrenia.

RECENT FINDINGS

We systematically searched PubMed and Embase for peer-reviewed studies on three topics: (1) sex differences in dose-adjusted antipsychotic serum concentrations, (2) hormonal augmentation therapy with estrogen and estrogen-like compounds to improve symptom severity, and (3) strategies to reduce antipsychotic-induced hyperprolactinemia. Based on three database studies and one RCT, we found higher dose-adjusted concentrations in women compared to men for most antipsychotics. For quetiapine, higher concentrations were specifically found in older women. Based on two recent meta-analyses, both estrogen and raloxifene improved overall symptomatology. Most consistent findings were found for raloxifene augmentation in postmenopausal women. No studies evaluated the effects of estrogenic contraceptives on symptoms. Based on two meta-analyses and one RCT, adjunctive aripiprazole was the best-studied and safest strategy for lowering antipsychotic-induced hyperprolactinemia. Evidence-based recommendations for female-specific pharmacotherapy for SSD consist of (1) female-specific dosing for antipsychotics (guided by therapeutic drug monitoring), (2) hormonal replacement with raloxifene in postmenopausal women, and (3) aripiprazole addition as best evidenced option in case of antipsychotic-induced hyperprolactinemia. Combining these strategies could reduce side effects and improve outcome of women with SSD, which should be confirmed in future longitudinal RCTs.

Age, Sex, and Comedication Effects on the Steady-State Plasma Concentrations of Amisulpride in Chinese Patients with Schizophrenia

BACKGROUND

Amisulpride, a second-generation atypical antipsychotic drug, was first marketed in Europe in the 1990s. This study aimed to provide a reference for the clinical application of amisulpride. The effects of age, sex, or specific comedications on amisulpride concentrations in Chinese patients with schizophrenia in the real world were investigated.

METHODS

A retrospective study was conducted of data on amisulpride based on the therapeutic drug monitoring service database at the Zigong Affiliated Hospital of Southwest Medical University.

RESULTS

Based on the inclusion criteria, 195 plasma samples from 173 patients (67.05% female and 32.95% male patients) were included for in-depth analysis. The median daily dose of amisulpride was 400 mg/d, median plasma concentration was 457.50 ng/mL, and median concentration/dose (C/D) ratio was 1.04 ng/mL/mg/d. The daily dose of amisulpride positively correlated with measured steady-state plasma concentrations. A significant difference was observed in the subgroup analysis of the combination with valproic acid, zopiclone, or aripiprazole on plasma concentrations. Combining amisulpride with these drugs increased the C/D ratios by 0.56-, 2.31-, and 0.77-fold, respectively. After adjusting for age, the median C/D ratio was found to be significantly different between female and male patients. However, no significant differences in daily dose, plasma concentration, and C/D ratio were noted with respect to sex and age of the patients.

CONCLUSIONS

Sex differences were inferred for the first time in this study, with differential effects on daily dose, steady-state plasma concentration, and C/D ratio associated with the population. In the included study samples, blood concentrations were distributed in the range of 223.25-823.55 ng/mL, which perhaps needs to be evaluated in line with the reference range of ammonia-sulfur ratios in the Chinese population.

Current Status of Therapeutic Drug Monitoring in Mental Health Treatment: A Review

Therapeutic drug monitoring (TDM) receives growing interest in different psychiatric clinical settings (emergency, inpatient, and outpatient services). Despite its usefulness, TDM remains underemployed in mental health. This is partly due to the need for evidence about the relationship between drug serum concentration and efficacy and tolerability, both in the general population and even more in subpopulations with atypical pharmacokinetics. This work aims at reviewing the scientific literature published after 2017, when the most recent guidelines about the use of TDM in mental health were written. We found 164 pertinent records that we included in the review. Some promising studies highlighted the possibility of correlating early drug serum concentration and clinical efficacy and safety, especially for antipsychotics, potentially enabling clinicians to make decisions on early laboratory findings and not proceeding by trial and error. About populations with pharmacokinetic peculiarities, the latest studies confirmed very common alterations in drug blood levels in pregnant women, generally with a progressive decrease over pregnancy and a very relevant dose-adjusted concentration increase in the elderly. For adolescents also, several drugs result in having different dose-related concentration values compared to adults. These findings stress the recommendation to use TDM in these populations to ensure a safe and effective treatment. Moreover, the integration of TDM with pharmacogenetic analyses may allow clinicians to adopt precise treatments, addressing therapy on an individual pharmacometabolic basis. Mini-invasive TDM procedures that may be easily performed at home or in a point-of-care are very promising and may represent a turning point toward an extensive real-world TDM application. Although the highlighted recent evidence, research efforts have to be carried on: further studies, especially prospective and fixed-dose, are needed to replicate present findings and provide clearer knowledge on relationships between dose, serum concentration, and efficacy/safety.

Comparative Safety Signal Assessment of Hospitalization Associated With the Use of Atypical Antipsychotics

Background

Persons with symptoms of psychosis receiving treatment with atypical antipsychotics (AAPs) can experience serious adverse events (AEs) requiring admission to the hospital. The comparative likelihood of AE-related hospitalization following the use of all AAPs has not been fully characterized. Therefore, we evaluated the safety signals of hospitalizations associated with the use of AAPs.

Methods

We conducted a cross-sectional analysis using the FDA Adverse Event Reporting System (FAERS) database (from January 1, 2004, to December 31, 2021) to examine disproportionality in reporting hospitalizations suspected to be associated with 12 AAPs (aripiprazole, asenapine, brexpiprazole, clozapine, iloperidone, lurasidone, olanzapine, paliperidone, and pimavanserin, quetiapine, risperidone, and ziprasidone). Hospitalization in the FAERs database is an outcome that is recorded as a result of an AE occurring at any drug dose. We estimated reporting odds ratios (RORs) by comparing the odds of hospitalization occurring with a particular AAP to the odds of its occurrence with other drugs. In addition, we considered the presence of a significant safety signal when the lower limit of the 95% confidence interval (CI) of the ROR is >1.

Results

A total of 204,287 cases of hospitalizations were reported to the FDA for individuals treated with AAPs. There were significant safety signals of hospitalization associated with using clozapine (ROR, 2.88; 95% CI, 2.84-2.92), olanzapine (ROR, 2.61; 95% CI, 2.57-2.64), quetiapine (ROR, 1.87; 95% CI, 1.85-1.89), risperidone (ROR, 1.41; 95% CI, 1.39-1.43), aripiprazole (ROR, 1.34; 95% CI, 1.32-1.35), and ziprasidone (ROR, 1.14; 95% CI, 1.10-1.18). However, no hospitalization-related safety signals were observed with the use of paliperidone, pimavanserin, iloperidone, asenapine, lurasidone, and brexpiprazole. The ROR estimates were numerically higher among older adults than younger adults.

Conclusions

This cross-sectional assessment of data from FAERs (2004-2021) suggested that users of clozapine, olanzapine, quetiapine, risperidone, aripiprazole, and ziprasidone were more likely to report being hospitalized than users of other AAPs. Given that the FAERs database only contains spontaneous reports of AEs experienced by persons exposed to a drug but without information on exposed persons who did not have an event, a cohort study comparing hospitalizations among new users of individual AAPs against each other is needed to delineate these safety signals further.

Effects of body weight, smoking status, and sex on plasma concentrations of once-monthly paliperidone palmitate

OBJECTIVES

Knowledge about the impact of body composition features on pharmacokinetics of newer long-acting injectable antipsychotics is limited.

METHODS

We analyzed steady-state plasma concentrations of paliperidone in different body mass index (BMI), age, sex, and smoking status patient subgroups treated with once-monthly paliperidone palmitate (PP1M). Paliperidone plasma concentrations and dose-adjusted-plasma concentrations (C/D) from a therapeutic drug monitoring (TDM) database of PP1M-treated patients were compared among normal BMI, overweight, and obese patients as well as between females vs. males, elderly vs. non-elderly, and smokers vs. non-smokers using non-parametric tests.

RESULTS

In a total of 183 PP1M-treated patients, we found highly variable paliperidone plasma concentrations between individuals but no significant effect of PP1M dose or dosing intervals (p> 0.05). C/D ratios were similar in 54 obese, 82 overweight, and 47 normal BMI patients (p> 0.05). Females had 13.7% higher C/D ratios compared to males, yet this difference was not significant (p> 0.05). No differences were found between elderly vs. non-elderly patients or for smokers vs. non-smokers (p> 0.05).

CONCLUSION

Our findings suggest that age, sex, smoking, or body weight may not substantially affect pharmacokinetic indices of PP1M. The high interindividual variation of plasma concentrations implies that TDM may be helpful to enhance PP1M efficacy and tolerability.