Inflammation and psychotropic drugs: the relationship between C-reactive protein and antipsychotic drug levels

Inflammation affects the pharmacokinetics of risperidone: Does the dose need to be adjusted during the acute-phase reaction?

BACKGROUND

Several studies have indicated that the plasma concentration of risperidone increases 3-5-fold during the acute-phase reaction (APR) of inflammation or infection. Psychiatric symptoms are present or deteriorate when the dose is lowered; thus, the complex effects of inflammation on the pharmacokinetics of risperidone need to be examined.

METHODS

We established a APR model in rabbits induced by lipopolysaccharide (LPS) and studied the effect of APR on pharmacokinetics, distribution and disposition of risperidone in vivo and in vitro.

RESULTS

Following intramuscular administration, the plasma exposures for risperidone and its active metabolite (9-hydroxyrisperidone) were increased approximately 6-fold on day 2 of inflammation. The exposure values did not change between day 2 and 5 of inflammation, nor did the metabolite-to-parent ratio before and during inflammation. Following oral administration, the increase of risperidone exposure was twice as high as that following intramuscular administration during APR. However, the concentration of risperidone and 9-hydroxyrisperidone in brain tissue was similar between the inflammatory and control groups. Moreover, the plasma protein binding (PPB) of risperidone and 9-hydroxyrisperidone associated with inflammation were all increased to >99 %. In addition, risperidone and 9-hydroxyrisperidone were not substrates of the key transporters, OATP1B3, OCT2, OAT3, MATE-1, or MATE-2 K. The expression of progesterone X receptor and P-glycoprotein was inhibited by LPS.

CONCLUSION

During APR, reduced expression of P-glycoprotein and increased PPB were responsible for increased exposure in plasma, while maintaining stable concentrations in the brain, and risperidone does not need to be dose-adjusted so as to achieve psychopharmacological outcomes.

Relationship between C-reactive protein and antipsychotics levels in schizophrenic patients infected with COVID-19

In the context of the COVID-19, inflammation emerges as a prominent characteristic. C-reactive protein (CRP) serves as a commonly employed marker for the evaluation of inflammation. This study aimed to examine the correlation between CRP levels and antipsychotic drug concentrations in patients diagnosed with SCZ during the COVID-19 pandemic. A total of 186 SCZ patients were included in this study, which utilized electronic medical records. The collected data encompassed SCZ diagnoses based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, respiratory symptoms, and treatments. Laboratory assessments involved the measurement of CRP levels and monitoring of blood drug concentrations. The most prevalent symptoms observed in the patient cohort were fever (59.14%), cough (52.15%), fatigue (45.7%), sore throat (46.24%), runny nose (28.49%), and stuffy nose (25.27%). The levels of CRP during the infection period were significantly higher compared to both the prophase and anaphase of infection (all p < 0.001). The serum levels of clozapine, olanzapine, aripiprazole, quetiapine, and risperidone were elevated during the infection period (all p < 0.001). During the anaphase of infection, patients exhibited higher serum levels of clozapine, olanzapine, and risperidone (all p < 0.001) compared to the infection period, but there was no significant change in serum levels of aripiprazole and quetiapine. Multiple regression analysis revealed a statistically significant positive correlation (P < 0.0001) between CRP and clozapine concentration. In light of the COVID-19 pandemic, it is crucial to adjust the dosage based on drug serum concentration to prevent intoxication or adverse drug reactions.

Effects of Sleeve Gastrectomy and Roux-en-Y Gastric Bypass on Escitalopram Pharmacokinetics: A Cohort Study

BACKGROUND

Changes in the gastrointestinal physiology after bariatric surgery may affect the pharmacokinetics of medications. Data on the impact of different surgical techniques on the pharmacokinetics of commonly prescribed antidepressants such as escitalopram are limited.

METHODS

This case-only prospective study investigated escitalopram-treated patients who underwent bariatric surgery at hospitals in Central Norway. Escitalopram concentrations were assessed using serial blood samples obtained during a dose interval of 24 hours preoperatively and at 1, 6, and 12 months, postoperatively. The primary outcomes were changes in the area under the time-concentration curve (AUC 0-24 ) with secondary outcomes, including full pharmacokinetic profiling. We performed repeated-measures analysis of variance for the AUC 0-24 and secondary outcomes.

RESULTS

Escitalopram-treated obese patients who underwent sleeve gastrectomy (n = 5) and Roux-en-Y gastric bypass (n = 4) were included. Compared with preoperative baseline, dose-adjusted AUC 0-24 values were within ±20% at all time points, postoperatively in the sleeve gastrectomy and oux-en-Y gastric bypass groups, with the largest changes occurring 1 month postoperatively (+14.5 and +17.2%, respectively). No statistically significant changes in any pharmacokinetic variables over time were reported; however, there was a trend toward increased maximum concentrations after surgery ( P = 0.069).

CONCLUSIONS

Our findings suggest that bariatric surgery has no systematic effect on the pharmacokinetics of escitalopram. However, because of the substantial interindividual variation, therapeutic drug monitoring can be considered to guide postoperative dose adjustments.

Association of clozapine and norclozapine levels with patient and therapy characteristics-focus on interaction with valproic acid

PURPOSE

The goal of the study was to examine clozapine (CLZ) and norclozapine (NCLZ) therapeutic drug monitoring (TDM) data and associated sources of pharmacokinetic variability, particularly the impact of valproic acid (VPA) use.

METHODS

This study included 126 patients with psychiatric disorders on mono- or co-therapy with CLZ. Patients' data during routine TDM were collected retrospectively from clinical records. The descriptive and statistical analysis was computed using IBM SPSS Statistics software (version 22, NY, USA). Multiple linear regression, based on the last observations, was used to assess correlation between demographic characteristics, life habits and co-therapy with dose-corrected serum levels (C/D) of CLZ and NCLZ, as well as CLZ/NCLZ.

RESULTS

A total of 295 CLZ concentrations were measured in 126 patients, with a mean of 275.5 ± 174.4 µg/L, while 124 NCLZ concentrations were determined in 74 patients, with a mean of 194.6 ± 149.8 µg/L. A statistically significant effect on ln-transformed CLZ C/D was confirmed for sex and smoking, whereas sex, smoking and VPA therapy were associated with ln-transformed NCLZ C/D. According to the final models, lower values of NCLZ C/D for about 45.9% can be expected in patients receiving VPA. Concomitant use of VPA was the only factor detected to contribute in CLZ/NCLZ variability.

CONCLUSION

The results of this study may help clinicians interpret TDM data and optimize CLZ dosing regimens, especially in patients concomitantly treated with VPA. Our results show that VPA primarily decreases NCLZ levels, while alteration of the parent drug is not statistically significant.

Inflammatory markers in outpatients with schizophrenia diagnosis in regular use of clozapine: a cross-sectional study

It is known that inflammation worsen the course of schizophrenia and induce high clozapine serum levels. However, no study evaluated this change in function of clozapine daily dose in schizophrenia. We assessed the correlation between inflammation and severity symptoms in patients with schizophrenia that take and do not take clozapine. We also assessed the correlation between clozapine daily dose and inflammatory markers to patients who take this drug. Patients were recruited from Schizophrenia Ambulatory and Psychosocial Care Center of Clinical Hospital of Porto Alegre and from an association of relatives of patients with schizophrenia. Exam results, and other important clinical exam were assessed in patients record or patients were asked to show their exam in the case of outpatients. We included 104 patients, 90 clozapine users and 14 non-clozapine users. We calculate the systemic inflammatory markers [neutrophil-lymphocyte ratio (NLR), systemic immune inflammation index (SII), and the psychopathology severity by the Brief Psychiatric Rating Scaled anchored (BPRS-a)]. These variables were compared between clozapine users and non-clozapine users. It was used mean/median test according to data distributing, with study factor (SII, MLR, and PLR), the clinical outcome: severity of symptomatology (BPRS score), and clozapine daily dose as adjustment factor. Clozapine users exhibited a significantly higher neutrophil count (mean ± SD: 5.03 ± 2.07) compared to non-clozapine users (mean ± SD: 3.48 ± 1.27; p = 0.031). After controlling for comorbidity, other parameters also showed significant differences. These findings are consistent with previous studies that have demonstrated an inflammatory response following the administration of clozapine.

Inflammatory markers in outpatients with schizophrenia diagnosis in regular use of clozapine: a cross-sectional study

It is known that inflammation worsen the course of schizophrenia and induce high clozapine serum levels. However, no study evaluated this change in function of clozapine daily dose in schizophrenia. We assessed the correlation between inflammation and severity symptoms in patients with schizophrenia that take and do not take clozapine. We also assessed the correlation between clozapine daily dose and inflammatory markers to patients who take this drug. Patients were recruited from Schizophrenia Ambulatory and Psychosocial Care Center of Clinical Hospital of Porto Alegre and from an association of relatives of patients with schizophrenia. Exam results, and other important clinical exam were assessed in patients record or patients were asked to show their exam in the case of outpatients. We included 104 patients, 90 clozapine users and 14 non-clozapine users. We calculate the systemic inflammatory markers [neutrophil-lymphocyte ratio (NLR), systemic immune inflammation index (SII), and the psychopathology severity by the Brief Psychiatric Rating Scaled anchored (BPRS-a)]. These variables were compared between clozapine users and non-clozapine users. It was used mean/median test according to data distributing, with study factor (SII, MLR, and PLR), the clinical outcome: severity of symptomatology (BPRS score), and clozapine daily dose as adjustment factor. Clozapine users exhibited a significantly higher neutrophil count (mean ± SD: 5.03 ± 2.07) compared to non-clozapine users (mean ± SD: 3.48 ± 1.27; p = 0.031). After controlling for comorbidity, other parameters also showed significant differences. These findings are consistent with previous studies that have demonstrated an inflammatory response following the administration of clozapine.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Is Vitamin B12 Level a Reliable Predictor of Psychosis Severity in Male Patients with Megaloblastic Anemia at a Single Tertiary Hospital?

Background

Megaloblastic anemia (MA) occurs due to ineffective erythropoiesis, which results from impaired DNA synthesis in the hematopoietic precursors and intramedullary hemolysis. MA’s most common cause is nutritional deficiencies of either cobalamin (vitamin B12) or folate (vitamin B6). This study aims to determine the association between MA caused by vitamin B12 deficiency and psychosis among psychotic male patients in Mental Health Hospital at Taif, Saudi Arabia.

Methods

Fifty psychotic male patients, aged 48.58±1.72, were recruited from the Mental Health Hospital at Taif, Saudi Arabia, in addition to 54 sex-matched healthy controls. The following tests were run: complete blood count (CBC), liver function tests (LFT), serum levels of vitamin B12, folate, and C-reactive protein (CRP).

Results

The CBC showed that RBCs count, haemoglobin, haematocrit, platelets count, mean platelets volume (MPV), and absolute lymphocyte count were significantly lower in psychotic patients versus healthy controls (P=0.007, P=0.002, P=0.001, P=0.004, P=0.0001, and P=0.005, respectively). In contrast, the eosinophil absolute count and basophil percentage were significantly higher in psychotic patients versus controls (P=0.009, P=0.0001, respectively). Vitamin B12 levels were insignificantly decreased in psychotic patients versus healthy group. There were significant negative correlations between serum levels of VitB12 and negative symptoms (r=−0.381, P=0.006) and hallucination (r=−0.297, P=0.036).

Conclusion

These findings indicate no link between MA induced by VitB12 insufficiency and psychosis among psychotic patients. However, low serum VitB12 can predict the severity of some psychosis signs, including hallucinations and negative symptoms. Therefore, monitoring VitB12 levels and its supplementation in psychotic patients is recommended to improve their symptoms.

Effect of quetiapine on inflammation and immunity: a systematic review

INTRODUCTION

Knowledge about the neurobiology of psychiatric disorders is increasing in the last decades and evidence from literature suggests a central role for immuno-inflammatory mechanisms in these illnesses. The antipsychotic quetiapine acts on dopamine and serotonin signalling and well-established evidence demonstrates that these neurotransmitters can modulate immune functions in healthy and diseased conditions. Starting from this perspective, in the last few decades, a number of studies attempted to identify quetiapine effects on immune functions in order to highlight a possible additional effect of this drug in psychotic diseases, although no conclusive results were obtained.

METHODS

We critically reviewed preclinical and clinical studies evaluating quetiapine effects on immune systems, suggesting strategies for future work in this field.

RESULTS

Computerised search, in PubMed and Embase databases, was performed in March 2020: 120 studies were identified but only 29 relevant papers were selected for detailed review.

CONCLUSION

Despite some interesting preliminary findings about anti-inflammatory effects of quetiapine, mainly supported by preclinical studies, it is possible to conclude further studies are needed to investigate the immunomodulatory effects of this drug and achieve a better understanding of its relevance on clinical outcomes to finally identify new therapeutic approaches in psychiatric treatment.KeypointsMounting evidence points to a role for immuno-inflammatory mechanisms in psychiatric disorders.Quetiapine (QUE) acts on catecholamine (dopamine and norepinephrine) and serotonin signalling.The immunomodulatory effects of catecholamines are well established.Treatment with QUE in psychiatric disorders could leverage immunomodulatory effects.QUE unclear role in immune function modulation suggests future work.

Roles of C-reactive protein polymorphisms and life event changes on cognitive function in bipolar patients receiving valproate

Introduction

Patients with bipolar disorder (BD) exhibit an inflamed condition that is associated with metabolic disturbance and cognitive impairment. Whether inflammation, represented by C-reactive protein (CRP), is causally associated with BD and influences treatment outcome has not been established.

Methods

We examined whether CRP is a causal factor for the risk of BD in drug-naïve, depressed BD patients and investigated whether polymorphisms in CRP and life event changes influence cognitive function in BD patients receiving valproate (VPA) treatment.

Results

Our results showed that BD patients had significantly higher CRP levels and worse cognitive function than the controls, while the frequencies of CRP single nucleotide polymorphisms in BD patients and in controls were not different. In addition, the life event scale score was higher for BD patients than for controls. Furthermore, the genotypes of CRP polymorphisms and the interactions between polymorphisms of CRP and life event scale score had a significant influence on cognitive performance in BD patients after 12 weeks of VPA treatment.

Conclusion

Our study demonstrated the clinical utility of the application of functional genetics in clarifying the interactions among CRP, life event stress, and BD and suggested the important roles of CRP gene–environment interactions in developing treatment strategies for BD.

The Cytokine Release Syndrome and/or the Proinflammatory Cytokines as Underlying Mechanisms of Downregulation of Drug Metabolism and Drug Transport: A Systematic Review of the Clinical Pharmacokinetics of Victim Drugs of this Drug-Disease Interaction Under Different Clinical Conditions

BACKGROUND AND OBJECTIVE

An ever-growing body of evidence supports the impact of cytokine modulation on the patient's phenotypic drug response. The aim of this systematic review was to analyze the clinical studies that assessed the pharmacokinetics of victim drugs of this drug-disease interaction in the presence of different scenarios of cytokine modulation in comparison with baseline conditions.

METHODS

We conducted a systematic review by searching the PubMed-MEDLINE database from inception until February 2022 to retrieve prospective and/or retrospective observational studies, population pharmacokinetic studies, phase I studies, and/or case series/reports that investigated the impact of cytokine modulation on the pharmacokinetic behavior of victim drugs. Only studies providing quantitative pharmacokinetic data of victim drugs by comparing normal status versus clinical conditions with documented cytokine modulation or by assessing the influence of anti-inflammatory biological agents on metabolism and/or transport of victim drugs were included.

RESULTS

Overall, 26 studies were included. Rheumatoid arthritis (6/26; 23.1%) and sepsis (5/26; 19.2%) were the two most frequently investigated pro-inflammatory clinical scenarios. The victim drug most frequently assessed was midazolam (14/26; 53.8%; as a probe for cytochrome P450 [CYP] 3A4). Cytokine modulation showed a moderate inhibitory effect on CYP3A4-mediated metabolism (area under the concentration-time curve increase and/or clearance decrease between 1.98-fold and 2.59-fold) and a weak-to-moderate inhibitory effect on CYP1A2, CYP2C9, and CYP2C19-mediated metabolism (in the area under the concentration-time curve increase or clearance decrease between 1.29-fold and 1.97-fold). Anti-interleukin-6 agents showed remarkable activity in counteracting downregulation of CYP3A4-mediated activity (increase in the area under the concentration-time curve between 1.75-fold and 2.56-fold).

CONCLUSIONS

Cytokine modulation may cause moderate or weak-to-moderate downregulation of metabolism/transport of victim drugs, and this may theoretically have relevant clinical consequences.

Influence of Inflammation on Cytochromes P450 Activity in Adults: A Systematic Review of the Literature

Background: Available in-vitro and animal studies indicate that inflammation impacts cytochromes P450 (CYP) activity via multiple and complex transcriptional and post-transcriptional mechanisms, depending on the specific CYP isoforms and the nature of inflammation mediators. It is essential to review the current published data on the impact of inflammation on CYP activities in adults to support drug individualization based on comorbidities and diseases in clinical practice. Methods: This systematic review was conducted in PubMed through 7th January 2021 looking for articles that investigated the consequences of inflammation on CYP activities in adults. Information on the source of inflammation, victim drugs (and CYPs involved), effect of disease-drug interaction, number of subjects, and study design were extracted. Results: The search strategy identified 218 studies and case reports that met our inclusion criteria. These articles were divided into fourteen different sources of inflammation (such as infection, autoimmune diseases, cancer, therapies with immunomodulator…). The impact of inflammation on CYP activities appeared to be isoform-specific and dependent on the nature and severity of the underlying disease causing the inflammation. Some of these drug-disease interactions had a significant influence on drug pharmacokinetic parameters and on clinical management. For example, clozapine levels doubled with signs of toxicity during infections and the concentration ratio between clopidogrel's active metabolite and clopidogrel is 48-fold lower in critically ill patients. Infection and CYP3A were the most cited perpetrator of inflammation and the most studied CYP, respectively. Moreover, some data suggest that resolution of inflammation results in a return to baseline CYP activities. Conclusion: Convincing evidence shows that inflammation is a major factor to be taken into account in drug development and in clinical practice to avoid any efficacy or safety issues because inflammation modulates CYP activities and thus drug pharmacokinetics. The impact is different depending on the CYP isoform and the inflammatory disease considered. Moreover, resolution of inflammation appears to result in a normalization of CYP activity. However, some results are still equivocal and further investigations are thus needed.

Elevated C-reactive protein levels across diagnoses: The first comparison among inpatients with major depressive disorder, bipolar disorder, or obsessive-compulsive disorder

OBJECTIVE

We addressed elevated C-reactive protein level (eCRP) specificity comparing, for the first time, eCRP (i.e., serum CRP > 3 and ≤10 mg/L) in patients with major depressive disorder (MDD), bipolar disorder (BD), or obsessive-compulsive disorder (OCD). We also assessed to what extent multiple variables that can potentially increase inflammation may have influenced eCRP in our sample.

METHODS

We performed a retrospective, observational, cross-sectional study using information documented in the electronic medical records (EMRs) of patients hospitalized for a 4-week psychiatric rehabilitation program. We collected all information according to the standardized procedures of the hospital's clinical practice and applied a logistic regression model (α = 0.05).

RESULTS

We included 388 inpatients, that is, 156 (40.2%) with MDD, 135 (34.8%) with BD, and 97 (25.0%) with OCD, and found considerable eCRP rates among them (36.5%, 47.4%, and 29.9% in MDD, BD, and OCD, respectively) but without significant differences across groups. In the whole sample, eCRP variations were only partially attributable (approximately for one-third) to potential confounders. All groups presented considerable rates of cardiovascular risk factors, and we classified most patients as having medium or high CRP-based cardiovascular risk.

CONCLUSION

This first study comparing eCRP in MDD, BD, and OCD suggests that eCRP may be a transdiagnostic feature of different psychiatric disorders, and other mechanisms beyond the effects of multiple confounders may explain the presence of eCRP in a substantial portion of psychiatric patients. Therefore, we encourage the routine measurement of CRP in psychiatric clinical practice.

Clozapine-induced myocarditis and patient outcomes after drug rechallenge following myocarditis: A systematic case review

Clozapine is underutilized due, in part, to concerns about rare but severe adverse drug reactions, including cardiac inflammation and injury (myocarditis). Risk factors for clozapine-induced myocarditis are limited and predictors for the successful rechallenge of clozapine after an episode of myocarditis are even more poorly understood. We conducted a systematic review, in accordance with the PRISMA recommendation, of published case reports to describe demographic and clinical characteristics of patients with clozapine-induced myocarditis and identify potential markers of clozapine rechallenge success. A total of 180 cases from 88 articles were evaluated. Male cases of clozapine-associated myocarditis were more frequently reported than female cases by a ratio of 6:1. Less than half of patients reported the presence of chest pain (35%) or flu-like symptoms (43%) but increases in troponin or C-reactive protein were present in 87% of cases. Clozapine rechallenge was carried out in 34 (2 female) cases, with successful reintroduction in 22 (2 female) cases (64.7%) and one fatality (2.9%). No demographic or clinical markers were significantly associated with rechallenge success after correction for multiple testing. Standardized reporting of clozapine-induced myocarditis cases is needed to facilitate the identification of factors associated with successful rechallenge.

Elevated acute phase proteins affect pharmacokinetics in COVID-19 trials: Lessons from the CounterCOVID - imatinib study

This study aimed to determine whether published pharmacokinetic (PK) models can adequately predict the PK profile of imatinib in a new indication, such as coronavirus disease 2019 (COVID‐19). Total (bound + unbound) and unbound imatinib plasma concentrations obtained from 134 patients with COVID‐19 participating in the CounterCovid study and from an historical dataset of 20 patients with gastrointestinal stromal tumor (GIST) and 85 patients with chronic myeloid leukemia (CML) were compared. Total imatinib area under the concentration time curve (AUC), maximum concentration (C_max) and trough concentration (C_trough) were 2.32‐fold (95% confidence interval [CI] 1.34–3.29), 2.31‐fold (95% CI 1.33–3.29), and 2.32‐fold (95% CI 1.11–3.53) lower, respectively, for patients with CML/GIST compared with patients with COVID‐19, whereas unbound concentrations were comparable among groups. Inclusion of alpha1‐acid glycoprotein (AAG) concentrations measured in patients with COVID‐19 into a previously published model developed to predict free imatinib concentrations in patients with GIST using total imatinib and plasma AAG concentration measurements (AAG‐PK‐Model) gave an estimated mean (SD) prediction error (PE) of −20% (31%) for total and −7.0% (56%) for unbound concentrations. Further covariate modeling with this combined dataset showed that in addition to AAG; age, bodyweight, albumin, CRP, and intensive care unit admission were predictive of total imatinib oral clearance. In conclusion, high total and unaltered unbound concentrations of imatinib in COVID‐19 compared to CML/GIST were a result of variability in acute phase proteins. This is a textbook example of how failure to take into account differences in plasma protein binding and the unbound fraction when interpreting PK of highly protein bound drugs, such as imatinib, could lead to selection of a dose with suboptimal efficacy in patients with COVID‐19.

E-Cigarette Use, Systemic Inflammation, and Depression

BACKGROUND

E-cigarette use (vaping) is an emerging public health problem. Depression has been found to be associated with e-cigarette use, and vaping and depression are each associated with elevated systemic inflammation. To date, the role of inflammation in the relationship between vaping and depression has not been explored.

OBJECTIVE

To assess the independent associations between e-cigarette use, depression, and inflammation, and to investigate whether the likelihood of depression among current e-cigarette users is associated with systemic inflammation.

METHODS

Nationally representative NHANES data from 2015-2018 were used (n = 4961). Systemic inflammation was defined as serum C-reactive protein (CRP) ≥ 8.0 mg/L. Depressed individuals were characterized by a score ≥ 10 on the Patient Health Questionnaire-9 (PHQ-9). Current e-cigarette users were defined as individuals who vaped at least once in the past 30 days and these individuals were stratified by use: exclusive users (reported smoking less than 100 combustible cigarettes in their lifetime), dual users (reported current use of electronic and combustible cigarettes), and e-cigarette users who were previous smokers. Bivariate analyses were used to assess independent associations between vaping, depression, and inflammation; and weighted logistic regression analyses adjusting for BMI, sex, and economic status were used to determine the odds ratios (ORs) for depression by e-cigarette category stratified by differential CRP levels.

RESULTS

Depression occurred in 16.7% of all e-cigarette users vs. 5.0% of those who never used e-cigarettes (p < 0.001). In adjusted analyses, the following elevated ORs were found: all current e-cigarette users with CRP <8 = 3.37 (95% CI: 2.06, 5.51) vs. CRP ≥8 = 6.70 (2.48, 18.11); exclusive e-cigarette users with CRP <8 = 1.91 (0.78, 4.69) vs. those with CRP ≥8 = 5.09 (1.44, 18.02); and dual users with CRP <8 = 4.31 (2.35, 7.89) vs. those with CRP ≥8 = 7.37 (1.85, 29.41). These ORs indicate that depression is associated with each category of e-cigarette use; however, we found this association did not vary by systemic inflammation level (interaction p-values > 0.05).

CONCLUSION

While a pattern of greater ORs for depression among e-cigarette users with elevated CRP provides provocative findings that might suggest a potential role of inflammation in the association between vaping and depression, we failed to find evidence that inflammation clearly moderates this association. While it is possible that depression among e-cigarette users may be influenced by systemic inflammation, a reproduction of the current study is necessary among a larger cohort to elucidate the effect of inflammation on depression among e-cigarette users.

Inflammation Suppresses Patients' Ability to Metabolize Cytochrome P450 Substrate Drugs

OBJECTIVE

To assess the impact of inflammation on cytochrome P450 (CYP) drug metabolism in human subjects.

DATA SOURCES

A PubMed search was done from 1980 to July 2021 limited to human subjects and English language using a search strategy of (((phase I metabolism) OR (CYP) OR (cytochrome P450)) AND (inflammatory OR inflammation)).

STUDY SELECTION AND DATA EXTRACTION

Narrative review of human studies assessing the impact of inflammation or inflammatory suppression with biologic drugs on CYP drug metabolism were used.

DATA SYNTHESIS

Patients with inflammatory conditions ranging from fungal, viral, or bacterial infections to noninfectious causes (critical illness, surgical procedure, cancer, or transplantation of stem cells or organs) have suppressed drug metabolism. Markers of inflammation such as C-reactive protein or α-1-acid glycoprotein are correlated with reduced clearance through CYP3A4, CYP1A2, and CYP2C19. Elevated interleukin-6 concentrations are also associated or correlated with reduced clearance for CYP3A4 and CYP2C-19 isoenzymes. There was insufficient information to properly assess CYP2D6.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Health professionals should appreciate that patients with acute or chronic inflammation from infectious or noninfectious causes could have suppressed drug metabolism through CYP3A4, CYP1A2, and CYP2C19. For narrow therapeutic index drugs, such as many of the drugs assessed in this review, that means more judicious drug monitoring to prevent adverse events.

CONCLUSIONS

Like other types of drug-drug or drug-disease interactions, inflammation can alter the steady-state concentration of CYP metabolized drugs.

Inflammation Induces Changes in the Functional Expression of P-gp, BCRP, and MRP2: An Overview of Different Models and Consequences for Drug Disposition

The ATP-binding cassette (ABC) transporters play a key role in drug pharmacokinetics. These membrane transporters expressed within physiological barriers can be a source of pharmacokinetic variability. Changes in ABC transporter expression and functionality may consequently affect the disposition of substrate drugs, resulting in different drug exposure. Inflammation, present in several acute and chronic diseases, has been identified as a source of modulation in drug transporter expression leading to variability in drug response. Its regulation may be particularly dangerous for drugs with a narrow therapeutic index. In this context, numerous in vitro and in vivo models have shown up- or downregulation in the expression and functionality of ABC transporters under inflammatory conditions. Nevertheless, the existence of contradictory data and the lack of standardization for the models used have led to a less conclusive interpretation of these data.

Infection is associated with elevated serum concentrations of antipsychotic drugs

We aimed to investigate the effects of infection on serum concentrations of different antipsychotics in inpatients with respiratory tract infections treated with psychiatric drugs, including risperidone, clozapine, quetiapine, and aripiprazole. All patients underwent therapeutic drug monitoring (TDM) and routine blood tests during infection and noninfection periods. The Wilcoxon signed-rank test was used to analyze intra-individual differences in dose-corrected serum concentrations (C/D) levels in infection and noninfection periods. To study the effects of infection intensity on drug concentrations, white blood cells (WBCs) parameters and C/D levels were analyzed by Spearman's correlation analysis using all samples. The median C/D levels of risperidone (risperidone + 9-OH, n = 36) and clozapine (n = 42) were significantly higher (P < 0.001), whereas the median C/D levels of quetiapine (n = 21) and aripiprazole (n = 13) were slightly significantly higher (P < 0.01) in infection than in noninfection period. A significant positive association between C/D levels and WBC parameters was observed for risperidone, clozapine, and quetiapine. These results indicated reduced clearance of all drugs evaluated, especially clozapine and risperidone, due to infection. Therefore, during infection in patients receiving risperidone, clozapine, quetiapine, or aripiprazole, TDM should be performed to minimize the possible adverse effects associated with elevated drug concentrations.

Selective Serotonin Reuptake Inhibitors and Clozapine: Clinically Relevant Interactions and Considerations

The monoamine hypothesis of depression attributes the symptoms of major depressive disorders to imbalances of serotonin, noradrenaline, and dopamine in the limbic areas of the brain. The preferential targeting of serotonin receptor (SERT) by selective serotonin reuptake inhibitors (SSRIs) has offered an opportunity to reduce the range of these side effects and improve patient adherence to pharmacotherapy. Clozapine remains an effective drug against treatment-resistant schizophrenia, defined as failing treatment with at least two different antipsychotic medications. Patients with schizophrenia who display a constellation of negative symptoms respond poorly to antipsychotic monotherapy. Negative symptoms include the diminution of motivation, interest, or expression. Conversely to the depressive symptomology of interest presently, supplementation of antipsychotics with SSRIs in schizophrenic patients with negative symptoms lead to synergistic improvements in the function of these patients. Fluvoxamine is one of the most potent inhibitors of CYP1A2 and can lead to an increase in clozapine levels. Similar increases in serum clozapine were detected in two patients taking sertraline. However, studies have been contradictory as well, showing no such increases, which are worrying. Clinicians should be aware that clozapine levels should be monitored with any coadministration with SSRIs.

Therapeutic Drug Monitoring of Second- and Third-Generation Antipsychotic Drugs-Influence of Smoking Behavior and Inflammation on Pharmacokinetics

Both inflammation and smoking can influence a drug’s pharmacokinetic properties, i.e., its liberation, absorption, distribution, metabolism, and elimination. Depending on, e.g., pharmacogenetics, these changes may alter treatment response or cause serious adverse drug reactions and are thus of clinical relevance. Antipsychotic drugs, used in the treatment of psychosis and schizophrenia, should be closely monitored due to multiple factors (e.g., the narrow therapeutic window of certain psychotropic drugs, the chronicity of most mental illnesses, and the common occurrence of polypharmacotherapy in psychiatry). Therapeutic drug monitoring (TDM) aids with drug titration by enabling the quantification of patients’ drug levels. Recommendations on the use of TDM during treatment with psychotropic drugs are presented in the Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology; however, data on antipsychotic drug levels during inflammation or after changes in smoking behavior—both clinically relevant in psychiatry—that can aid clinical decision making are sparse. The following narrative review provides an overview of relevant literature regarding TDM in psychiatry, particularly in the context of second- and third-generation antipsychotic drugs, inflammation, and smoking behavior. It aims to spread awareness regarding TDM (most pronouncedly of clozapine and olanzapine) as a tool to optimize drug safety and provide patient-tailored treatment.

Therapeutic Drug Monitoring of Second- and Third-Generation Antipsychotic Drugs—Influence of Smoking Behavior and Inflammation on Pharmacokinetics

Both inflammation and smoking can influence a drug’s pharmacokinetic properties, i.e., its liberation, absorption, distribution, metabolism, and elimination. Depending on, e.g., pharmacogenetics, these changes may alter treatment response or cause serious adverse drug reactions and are thus of clinical relevance. Antipsychotic drugs, used in the treatment of psychosis and schizophrenia, should be closely monitored due to multiple factors (e.g., the narrow therapeutic window of certain psychotropic drugs, the chronicity of most mental illnesses, and the common occurrence of polypharmacotherapy in psychiatry). Therapeutic drug monitoring (TDM) aids with drug titration by enabling the quantification of patients’ drug levels. Recommendations on the use of TDM during treatment with psychotropic drugs are presented in the Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology; however, data on antipsychotic drug levels during inflammation or after changes in smoking behavior—both clinically relevant in psychiatry—that can aid clinical decision making are sparse. The following narrative review provides an overview of relevant literature regarding TDM in psychiatry, particularly in the context of second- and third-generation antipsychotic drugs, inflammation, and smoking behavior. It aims to spread awareness regarding TDM (most pronouncedly of clozapine and olanzapine) as a tool to optimize drug safety and provide patient-tailored treatment.

Therapeutic Drug Monitoring of Second- and Third-Generation Antipsychotic Drugs-Influence of Smoking Behavior and Inflammation on Pharmacokinetics

Both inflammation and smoking can influence a drug's pharmacokinetic properties, i.e., its liberation, absorption, distribution, metabolism, and elimination. Depending on, e.g., pharmacogenetics, these changes may alter treatment response or cause serious adverse drug reactions and are thus of clinical relevance. Antipsychotic drugs, used in the treatment of psychosis and schizophrenia, should be closely monitored due to multiple factors (e.g., the narrow therapeutic window of certain psychotropic drugs, the chronicity of most mental illnesses, and the common occurrence of polypharmacotherapy in psychiatry). Therapeutic drug monitoring (TDM) aids with drug titration by enabling the quantification of patients' drug levels. Recommendations on the use of TDM during treatment with psychotropic drugs are presented in the Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology; however, data on antipsychotic drug levels during inflammation or after changes in smoking behavior-both clinically relevant in psychiatry-that can aid clinical decision making are sparse. The following narrative review provides an overview of relevant literature regarding TDM in psychiatry, particularly in the context of second- and third-generation antipsychotic drugs, inflammation, and smoking behavior. It aims to spread awareness regarding TDM (most pronouncedly of clozapine and olanzapine) as a tool to optimize drug safety and provide patient-tailored treatment.

A high-fat diet, but not haloperidol or olanzapine administration, increases activated microglial expression in the rat brain

This study examined the effects of chronic treatment of the antipsychotic drugs, haloperidol and olanzapine, on microglial activation in the brain. In addition, we explored the interaction of these antipsychotic drugs with normal and high-fat diet. In order to measure activated microglial expression, we used [³H] PK11195 in vitro autoradiography. Male Sprague Dawley rats were given a diet of either regular chow diet or a high-fat diet, and assigned either water, haloperidol drinking solution (1.5 mg/kg), or olanzapine drinking solution (10 mg/kg) for four weeks. Following treatment, rats were euthanized and brains extracted for [³H] PK11195 autoradiography. Rats on 4 weeks of a high-fat diet showed increased [³H] PK11195 binding compared to rats on a normal diet in the temporal association cortex (19 %), ectorhinal cortex (17 %), entorhinal cortex (18 %), and perirhinal cortex (18 %), irrespective of drug treatment. These are regions associated with memory, sensory, and visual processing. Rats treated with either haloperidol or olanzapine showed no differences in [³H] PK11195 binding compared to the control group. However, there were differences between the 2 different antipsychotic medications themselves. Haloperidol increased [³H] PK11195 binding in the amygdala (23 %), ectorhinal cortex (24 %), and perihinal cortex (29 %), compared to olanzapine. These results corroborate a known role of a high-fat diet and central inflammatory changes but suggest no role of these antipsychotic drugs in promoting neuroinflammation across 4 weeks compared to normal control rats.

The Influence of Pharmacogenetics on the Clinical Relevance of Pharmacokinetic Drug-Drug Interactions: Drug-Gene, Drug-Gene-Gene and Drug-Drug-Gene Interactions

Drug interactions are a well-known cause of adverse drug events, and drug interaction databases can help the clinician to recognize and avoid such interactions and their adverse events. However, not every interaction leads to an adverse drug event. This is because the clinical relevance of drug-drug interactions also depends on the genetic profile of the patient. If inhibitors or inducers of drug metabolising enzymes (e.g., CYP and UGT) are added to the drug therapy, phenoconcversion can occur. This leads to a genetic phenotype that mismatches the observable phenotype. Drug-drug-gene and drug-gene-gene interactions influence the toxicity and/or ineffectivness of the drug therapy. To date, there have been limited published studies on the impact of genetic variations on drug-drug interactions. This review discusses the current evidence of drug-drug-gene interactions, as well as drug-gene-gene interactions. Phenoconversion is explained, the and methods to calculate the phenotypes are described. Clinical recommendations are given regarding the integratation of the PGx results in the assessment of the relevance of drug interactions in the future.

Clozapine intoxication with severe adverse effects induced by an inflammatory and infectious process: a case report

Background

Clozapine intoxication can be life-threatening. Outside of the common drug–drug interactions, tobacco smoking, and caffeine consumption, infectious and inflammatory processes are important contributors to clozapine intoxication. Although this relationship has been reported previously, the literature is scant of proper research articles describing the presentation and management of this unpredictable interaction. Therefore, clinicians need to rely heavily on case reports describing clozapine intoxication caused by inflammation and/or infection.

Case presentation

A 64-year-old Caucasian woman known for schizophrenia was brought to the emergency department (ED) with severe signs and symptoms of clozapine intoxication (general deterioration, drowsiness, neutropenia, and ileus). She was on clozapine 700 mg daily amongst other medications. The clozapine dose was stable for over 3 years, and there were no recent changes in her medications. The initial culprit was determined to be an infectious/inflammatory process of gastrointestinal origin with contribution from dehydration and constipation. Clozapine and norclozapine serum concentrations confirmed the intoxication: 1315 ng/mL and 653 ng/mL, respectively. She drastically improved with clozapine dose reduction and antibiotic therapy. She remained stable for years with clozapine 600 mg daily with stable clozapine serum levels.

Conclusion

This case report illustrates the possibility of severe toxicity associated with an acute infectious and/or inflammatory process in patients on clozapine therapy. Clinicians must maintain a high level of suspicion in patients taking clozapine who develop and an infectious and/or inflammatory process. Constipation secondary to clozapine intoxication can exacerbate the initial intoxication process.

Effects of Broad Spectrum Antibiotics on Measurement of Immunosuppressant Drugs

BACKGROUND

Antibiotics used parenterally can affect blood drug level measurements, as measured in diagnostic tests.

OBJECTIVE

To investigate the effect of six different antibiotics commonly used in intensive care units on tacrolimus, sirolimus, everolimus and cyclosporin A levels measured by mass spectrometry.

METHODS

Ampicillin + sulbactam (AB1, IV, 1 g), imipenem + cilastatin sodium (AB2, IV, 500 mg), piperacillin + tazobactam (AB3, 4.5 g, IV), ertapenem (AB4, IV, 1 g), meropenem trihydrate (AB5, 500 mg, IV) and ceftriaxone (AB6, 1 g, IV) antibiotics were used for the interference assay. Measurements were performed on the Shimadzu 8045 (Japan) LC-MS/MS instrument. Bias values were calculated.

RESULTS

The least affected immunosuppressant was cyclosporine A (between -6.88% and 3.40%). The most affected were everolimus and sirolimus. Ertapenem caused negative interference on the level of everolimus at the rate of -27.34% and sirolimus at the rate of -26.79%. Piperacillin + tazobactam and imipenem + cilastatin sodium caused positive interferences on sirolimus at the rate of 24.24% and 22.73%, respectively. Ampicillin + sulbactam, meropenem trihydrate and ceftriaxone affected the sirolimus levels at lower rates (-4.49%, 5.93% and 9.86%). Everolimus levels deviated at the rate of -11.21% to -16.99% due to imipenem + cilastatin sodium, meropenem trihydrate and ceftriaxone.

CONCLUSION

This study demonstrated the potential of antibiotic use affecting immunosuppressant levels. Antibiotic interference, especially in transplant patients, may cause erroneous immunosuppression, increasing the likelihood of rejection.

Relationship Between Curative Effect and Serum Inflammatory Factors Level in Male Patients With First-Episode Schizophrenia Treated With Olanzapine

Background: A growing body of evidence shows that immune system disorders are one of the important etiological factors of schizophrenia. Inflammatory cytokines play a very critical role in the pathogenesis and treatment of schizophrenia. However, in the actual clinical practice, there is still a lack of confirmed biological indicators that can be used to evaluate the therapeutic effect of antipsychotics. Methods: In this study, 82 male patients with first-episode schizophrenia and 30 healthy controls were included. The Positive and Negative Syndrome Scale (PANSS) scores were evaluated, and the serum levels of high-sensitivity C-reactive protein (hs-CRP), interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 17 (IL-17), and transforming growth factor β1 (TGF-β1) were detected, both at baseline and 4 weeks later. The patients were divided into two groups, the effective group and the ineffective group, according to the reduction rate of PANSS. Results: In the case group, the levels of hs-CRP were significantly elevated (p = 0.00), whereas IL-1β, IL-6, and IL-17 were significantly reduced as compared to the baseline (p = 0.01, 0.02, and 0.00, respectively). Importantly, the baseline levels of the five inflammatory factors were significantly higher in the case group as compared to the control group (p = 0.00, 0.00, 0.00, 0.00, and 0.00, respectively). Post-treatment, the serum levels for IL-1β, IL-6, and IL-17 were significantly higher in the effective group than in the ineffective group (p = 0.00, 0.00, and 0.01, respectively). For every increase in the amount of IL-1β, the risk of ineffectiveness increased by 7% (OR = 0.93 [0.86-1.00]; p = 0.04), whereas for every increase in the amount of IL-17, the risk of ineffectiveness increased by 5% (OR = 0.95 [0.90-0.99]; p = 0.03). Conclusion: The results of the study showed that the levels of inflammatory factors in patients with different therapeutic effects were different, and the changes in the amounts of IL-1β and IL-17 acted as predictors of poor efficacy.

Clinically Relevant Interactions between Atypical Antipsychotics and Anti-Infective Agents

This is a comprehensive review of the literature on drug interactions (DIs) between atypical antipsychotics and anti-infective agents that focuses on those DIs with the potential to be clinically relevant and classifies them as pharmacokinetic (PK) or pharmacodynamic (PD) DIs. PubMed searches were conducted for each of the atypical antipsychotics and most commonly used anti-infective agents (13 atypical antipsychotics by 61 anti-infective agents/classes leading to 793 individual searches). Additional relevant articles were obtained from citations and from prior review articles written by the authors. Based on prior DI articles and our current understanding of PK and PD mechanism, we developed tables with practical recommendations for clinicians for: antibiotic DIs, antitubercular DIs, antifungal DIs, antiviral DIs, and other anti-infective DIs. Another table reflects that in clinical practice, DIs between atypical antipsychotics and anti-infective agents occur in patients also suffering an infection that may also influence the PK and PD mechanisms of both drugs (the atypical antipsychotic and the anti-infective agent(s)). These tables reflect the currently available literature and our current knowledge of the field and will need to be updated as new DI information becomes available.

[Pharmacokinetic changes related to acute infection. Examples from the SARS-CoV-2 pandemic]

The knowledge of factors of pharmacokinetic variability is important in order to personalize pharmacological treatment, particularly for drugs with a narrow therapeutic range for which pharmacological therapeutic monitoring is recommended. Inflammation is a protective response against acute infections and injuries that contributes to intra- and inter-individual variability in drug exposure by modulating the activity of enzymes involved in drug metabolism, and by altering the binding of drugs to plasma proteins. The understanding of the impact of inflammation on drug metabolism and the related clinical consequences allow to better take into consideration the effect of inflammation on the variability of drug exposure. We first summarized the molecular mechanisms by which inflammation contributes to the inhibition of drug metabolism enzymes. We then presented an updated overview of the consequences of the outcome of acute infectious event on pharmacokinetic exposure of drugs with a narrow therapeutic range and that are substrates of cytochrome P450, and the related clinical consequences. Finally, in the context of the COVID-19 pandemic, we reported examples of drug overexposures in COVID- 19 infected patients.

Unmetabolized quetiapine exerts an in vitro effect on innate immune cells by modulating inflammatory response and neutrophil extracellular trap formation

Quetiapine is an antipsychotic drug that is used to treat psychiatric and neurological disorders. Despite its efficiency and low-toxicity, quetiapine administration has been associated with undesirable side effects such as the development of low-grade inflammatory disorders and neutropenia states. As the liver rapidly metabolizes quetiapine to metabolites, the non-metabolized part of this molecule might play a role in immune alterations. In an in vitro study, this hypothesis was tested by exposing activated and inactivated RAW-264.7 macrophages and human neutrophils to unmetabolized quetiapine (u-QUE). Based on our findings, u-QUE was not cytotoxic to these cells. u-QUE differentially modulates macrophages according to their activation states. In inactivated macrophages, u-QUE induced a proinflammatory state as observed by an increase in cellular proliferation; increased levels of oxidative molecules (nitric oxide and superoxide), protein levels, and gene overexpression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α); and decreased levels of IL-10, an anti-inflammatory cytokine. Conversely, on phytohemagglutinin (PHA)-activated macrophages, u-QUE exerted an anti-inflammatory effect. u-QUE induced neutrophil extracellular trap (NET) formation and increased the sensitivity of the neutrophils previously activated by exposure to dead yeast cells for NET formation. These results confirm the effect of quetiapine on macrophage and neutrophil function, which may be associated with the side effects of this psychopharmaceutical agent.

Effect of Systemic Inflammatory Response to SARS-CoV-2 on Lopinavir and Hydroxychloroquine Plasma Concentrations

Coronavirus disease 2019 (COVID-19) leads to inflammatory cytokine release, which can downregulate the expression of metabolizing enzymes. This cascade affects drug concentrations in the plasma. We investigated the association between lopinavir (LPV) and hydroxychloroquine (HCQ) plasma concentrations and the levels of the acute-phase inflammation marker C-reactive protein (CRP). LPV plasma concentrations in 92 patients hospitalized at our institution were prospectively collected. Lopinavir-ritonavir was administered every 12 hours, 800/200 mg on day 1 and 400/100 mg on day 2 until day 5 or 7. HCQ was given at 800 mg, followed by 400 mg after 6, 24, and 48 h. Hematological, liver, kidney, and inflammation laboratory values were analyzed on the day of drug level determination. The median age of study participants was 59 (range, 24 to 85) years, and 71% were male. The median durations from symptom onset to hospitalization and treatment initiation were 7 days (interquartile range [IQR], 4 to 10) and 8 days (IQR, 5 to 10), respectively. The median LPV trough concentration on day 3 of treatment was 26.5 μg/ml (IQR, 18.9 to 31.5). LPV plasma concentrations positively correlated with CRP values (r = 0.37, P < 0.001) and were significantly lower when tocilizumab was preadministered. No correlation was found between HCQ concentrations and CRP values. High LPV plasma concentrations were observed in COVID-19 patients. The ratio of calculated unbound drug fraction to published SARS-CoV-2 50% effective concentrations (EC₅₀) indicated insufficient LPV concentrations in the lung. CRP values significantly correlated with LPV but not HCQ plasma concentrations, implying inhibition of cytochrome P450 3A4 (CYP3A4) metabolism by inflammation.

Antipsychotic medications and the progression of upper respiratory infection to pneumonia in patients with schizophrenia

Aim Research regarding the effect of antipsychotic medications on the risk of upper respiratory infection (URI) progression to pneumonia in patients with schizophrenia is rare. This study investigated the effect of antipsychotic use on the risk of URI progression to pneumonia in patients with schizophrenia.

METHODS

This cohort study used the Taiwan's Nationwide Psychiatric Inpatient Medical Claims Database. From January 1, 1996 to December 31, 2012, 22,771 patients with schizophrenia were diagnosed as having the first URI episode after their first psychiatric admission and 135 of them developed pneumonia within 30 days. The duration and dosage of antipsychotics were assessed before and after URI. Cox regression with time-dependent model was used to assess the risk of antipsychotic use on the progression of URI to pneumonia.

RESULTS

Among first- and second-generation antipsychotics, clozapine was the only medication associated with an increased risk of developing pneumonia before URI (adjusted hazard ratio [aHR] = 2.05, P = .024). Clozapine was also the only drug significantly associated with an increased risk after URI (aHR = 1.92, P = .027). Regarding medication use after URI, the dosage of clozapine was significantly associated with an increased risk based on Cox regression with a time-dependent model (aHR = 1.95, P = .003).

CONCLUSIONS

The use of clozapine was associated with URI progression to pneumonia in patients with schizophrenia. The dosage of clozapine used in the post-URI period was also associated with an increased risk. Clinicians should consider lowering clozapine dosage in patients with URI to prevent them developing pneumonia.

Inflammation is a major regulator of drug metabolizing enzymes and transporters: Consequences for the personalization of drug treatment

Inflammation is an evolutionary process that allows survival against acute infection or injury. Inflammation is also a pathophysiological condition shared by numerous chronic diseases. In addition, inflammation modulates important drug-metabolizing enzymes and transporters (DMETs), thus contributing to intra- and interindividual variability of drug exposure. A better knowledge of the impact of inflammation on drug metabolism and its related clinical consequences would help to personalize drug treatment. Here, we summarize the kinetics of inflammatory mediators and the underlying transcriptional and post-transcriptional mechanisms by which they contribute to the inhibition of important DMETs. We also present an updated overview of the effect of inflammation on the pharmacokinetic parameters of most of the drugs that are DMET substrates, for which therapeutic drug monitoring is recommended. Furthermore, we provide opinions on how to integrate the inflammatory status into pharmacogenetics, therapeutic drug monitoring, and population pharmacokinetic strategies to improve the personalization of drug treatment for each patient.

[Psychopharmacotherapy during the COVID-19 pandemic]

Im Rahmen der aktuellen coronavirus disease 2019(COVID-19)-Pandemie müssen sich viele Bereiche der Medizin umstrukturieren. Dies betrifft auch die Versorgung von Patienten mit psychischen Erkrankungen. Die Therapie psychischer Erkrankungen umfasst psychotherapeutische und psychopharmakologische Interventionen. Letztere können mit einer Vielzahl an unerwünschten Arzneimittelwirkungen (UAW) assoziiert sein, stellen aber in der aktuellen Situation mit Kontakt- und Ausgangsbeschränkungen die präferierte Therapieoption dar. Da der direkte Patientenkontakt zugunsten des Telefonats oder der Videokonferenz reduziert ist, müssen angepasste diagnostische und therapeutische Optionen gefunden werden, um eine ausreichende Patientensicherheit zu gewährleisten. Bedeutend sind hierbei die ausführliche Aufklärung der Patienten sowie eine aktive Abfrage von Symptomen zur rechtzeitigen Erkennung von UAW. Unter der Behandlung mit Psychopharmaka sind UAW zu befürchten, die besonders ungünstig sind, wenn sie im Rahmen einer akuten Infektion auftreten oder ein erhöhtes Infektionsrisiko begünstigen. Hierzu gehören Atemdepression, Agranulozytose, Intoxikation durch Hemmung des Arzneistoffmetabolismus und venöse Thromboembolien, die jeweils mit potenziell lebensbedrohlichen Folgen einhergehen. Gleichzeitig sollte auf eine ausreichende Wirksamkeit der Medikation geachtet werden, da die gegenwärtige Krise zu einer Exazerbation vorbestehender psychischer Erkrankungen führen bzw. deren Erstmanifestation begünstigen kann.

Understanding variability in the pharmacokinetics of atypical antipsychotics - focus on clozapine, olanzapine and aripiprazole population models

Antipsychotic medicines are widely used for the management of psychotic symptoms regardless of the underlying diagnosis. Most atypical antipsychotics undergo extensive metabolism prior to excretion. Various factors may influence their pharmacokinetics, particularly elimination, leading to highly variable drug concentrations between individual patients following the same dosing regimen. Population pharmacokinetic approach, based on nonlinear mixed effects modeling, is a useful tool to identify covariates explaining pharmacokinetic variability, as well as to characterize and distinguish unexplained residual and between-subject (interindividual) variability. In addition, this approach allows the use of both sparsely and intensively sampled data. In this paper, we reviewed the pharmacokinetic characteristics of clozapine, olanzapine and aripiprazole, focusing on a population modeling approach. In particular, models based on a nonlinear mixed effects approach performed by NONMEM^® software in order to identify and quantify sources of pharmacokinetic variability are presented. Population models were identified through systematic searches of PubMed and sixteen studies were selected. Some of the factors identified that significantly contribute to variability in elimination among clozapine, olanzapine, and aripiprazole are demographic characteristics, body weight, genetic polymorphism, smoking and in some cases drug interactions. Scientific research based on pharmacometric modeling is useful to further characterize sources of variability and their combined effect.

Immunoendocrine Peripheral Effects Induced by Atypical Antipsychotics

Atypical antipsychotics (AAP) or second-generation antipsychotics are the clinical option for schizophrenia treatment during acute psychoses, but they are also indicated for maintenance during lifetime, even though they are being used for other psychiatric conditions in clinical practice such as affective disorders and autism spectrum disorder, among others. These drugs are differentiated from typical antipsychotics based on their clinical profile and are a better choice because they cause fewer side effects regarding extrapyramidal symptoms (EPS). Even though they provide clear therapeutic benefits, AAP induce peripheral effects that trigger phenotypic, functional, and systemic changes outside the Central Nervous System (CNS). Metabolic disease is frequently associated with AAP and significantly impacts the patient's quality of life. However, other peripheral changes of clinical relevance are present during AAP treatment, such as alterations in the immune and endocrine systems as well as the intestinal microbiome. These less studied alterations also have a significant impact in the patient's health status. This manuscript aims to revise the peripheral immunological, endocrine, and intestinal microbiome changes induced by AAP consumption recommended in the clinical guidelines for schizophrenia and other psychiatric disorders.

Changes in inflammation with treatment for bipolar II depression: Pilot trial data on differential effects of psychotherapy and medication

OBJECTIVES

Limited prospective data, mostly focused on bipolar I disorder, suggests that pro-inflammatory cytokines are elevated in abnormal mood states. We evaluated whether treatment normalizes peripheral markers of inflammation in bipolar II disorder.

METHODS

Using data from a randomized clinical trial of Interpersonal and Social Rhythm Therapy (IPSRT) + quetiapine vs. IPSRT + placebo for bipolar II depression, we examined whether these treatments for bipolar II depression impact inflammatory cytokines and whether observed changes in cytokines are associated with changes in depressive symptomatology as measured by the Hamilton Rating Scale for Depression (HRSD-17).

RESULTS

Cytokine values were available for 33 participants who completed baseline and 20-week followup visits. After excluding those with CRP values >=10 mg/L, there were 27 patients available for analysis (IPSRT+quetiapine N=10, IPSRT+placebo N=17). Baseline measure of inflammation did not appear to moderate treatment response, nor was change in HRSD-17 score correlated with changes in cytokines. Those who received IPSRT+quetiapine had significantly greater increases in IL-6 (p=0.02) and TNF-α (p=0.04), even after adjusting for changes in body mass index, than the IPSRT alone group. Descriptively, the quetiapine group showed increases in pro-inflammatory and decreases in anti-inflammatory cytokines and the psychotherapy group showed reduced pro-inflammatory cytokines.

CONCLUSIONS

Despite both groups showing depression improvement, this small study suggests a more pro-inflammatory cytokine profile over time with quetiapine plus psychotherapy compared to psychotherapy alone. Elevated risk of cardiovascular morbidity and mortality among those with bipolar II disorder underscores the importance of delivering treatments that do not exacerbate these risk factors.

Personalizing dosing of risperidone, paliperidone and clozapine using therapeutic drug monitoring and pharmacogenetics

By combining knowledge of pharmacogenetics, therapeutic drug monitoring (TDM) and drug-drug interactions (DDIs) the author developed a model for personalizing antipsychotic dosing, which is applied to risperidone, 9-hydroxyrisperidone or paliperidone, and clozapine. Drugs are approved using an average dose for an ideal average patient, but pharmacologists have described outliers: genetic poor metabolizers (PMs) and ultrarapid metabolizers (UMs). Environmental and personal variables can also make patients behave as PMs or UMs. Drug clearance is represented by the concentration-to-dose (C/D) ratio under steady-state and trough conditions. A very low C/D ratio indicates a UM, while a very high C/D ratio indicates a PM. Total risperidone C/D ratio for the oral formulation is around 7 ng/ml per mg/day and can be influenced by CYP2D6 polymorphism, DDIs with inducers and inhibitors, and renal function. Oral paliperidone has low availability; its C/D ratio is around 4.1 ng/ml per mg/d and can be influenced by inducers and renal impairment. Once-a-month long-acting paliperidone provides a C/D ratio around 7.7 ng/ml per mg/day at steady state, which is expected to be in the 8th month (before the 9th injection). TDM is particularly important for long-acting paliperidone formulations that may accumulate once steady state is reached (after years for the 3- and 6-month formulations). In the US, clozapine C/D ratios typically range from 0.6 (male smokers) to 1.2 (female non-smokers) ng/ml per mg/day. East Asians' clozapine C/D ratios appear to be twice as high. Inhibitors (including fluvoxamine and oral contraceptives) and inflammation can also increase clozapine C/D ratios. This article is part of the issue entitled 'Special Issue on Antipsychotics'.

Unbound Fraction of Clozapine Significantly Decreases with Elevated Plasma Concentrations of the Inflammatory Acute-Phase Protein Alpha-1-Acid Glycoprotein

Background

During inflammation, elevated total (unbound plus protein-bound) clozapine plasma concentrations have been observed. Elevated alpha-1-acid glycoprotein concentrations during inflammation are suggested to cause increased plasma clozapine-alpha-1-acid glycoprotein binding, resulting in elevated total clozapine plasma concentrations without significant changes in unbound concentrations. Here, we investigated the association between alpha-1-acid glycoprotein plasma concentrations and clozapine unbound fraction.

Methods

First, 25 and 60 µL of alpha-1-acid glycoprotein solution (20 mg/mL) were added to plasma samples (n = 3) of clozapine users (spiking experiment). Second, the association between alpha-1-acid glycoprotein plasma concentration and clozapine unbound fraction was assessed in patient samples (patient study). Samples were determined by liquid chromatography-tandem mass spectrometry. Data were analyzed with a paired t test (spiking experiment) and an unpaired t test (patient study).

Results

The spiking experiment showed significantly lower mean unbound fractions following 25- and 60-µL alpha-1-acid glycoprotein spikes (relative reductions of 28.3%, p = 0.032 and 43.4%, p = 0.048). In the patient study, total clozapine plasma concentrations were 10% higher in elevated (n = 6) compared with normal alpha-1-acid glycoprotein (n = 20) samples [525 µg/L vs. 479 µg/L, mean difference = 47 µg/L (95% confidence interval −217 to 310), p = 0.72]. Elevated alpha-1-acid glycoprotein samples had a 26% lower mean unbound fraction compared with normal samples [1.22% vs. 1.65%, mean difference = −0.43% (95% confidence interval −0.816 to −0.0443), p = 0.03].

Conclusions

Both the spiking experiment and patient study showed a significant association between elevated alpha-1-acid glycoprotein plasma concentrations and a lower clozapine unbound fraction. Future studies should include clinical data to examine whether this association is clinically relevant, suggesting any clozapine dose adjustments.

A comprehensive review of swallowing difficulties and dysphagia associated with antipsychotics in adults

INTRODUCTION

This is a comprehensive review of antipsychotic (AP)-induced dysphagia and its complications: choking and pneumonia. Areas covered: Four PubMed searches were completed in 2018. The limited literature includes: 1) 45 case reports of AP-induced dysphagia with pharmacological mechanisms, 2) a systematic review of APs as a risk factor for dysphagia, 3) reviews suggesting adult patients with intellectual disability (ID) and dementia are prone to dysphagia (APs are a risk factor among multiple others), 4) studies of the increased risk of choking in patients with mental illness (APs are a contributing factor), 5) naturalistic pneumonia studies suggesting that pneumonia may contribute to AP-increased death in dementia, and 6) naturalistic studies suggesting that pneumonia may be a major cause of morbidity and mortality in clozapine patients. Expert commentary: The 2005 Food and Drug Administration requirement that package inserts warn of AP-induced dysphagia jumpstarted this area, but current studies are limited by: 1) its naturalistic nature, 2) the lack of dysphagia studies of patients with IDs and dementia on APs, and 3) the assumed indirect association between dysphagia with choking and pneumonia. Future clozapine studies on pneumonia, if they lead to a package insert warning, may have high potential to save lives.

Physiologically Based Modeling Approach to Predict Dopamine D2 Receptor Occupancy of Antipsychotics in Brain: Translation From Rat to Human

Receptor occupancy (RO) is a translational biomarker for assessing drug efficacy and safety. We aimed to apply a physiologically based pharmacokinetic (PBPK) modeling approach to predict the brain dopamine D2 RO time profiles of antipsychotics. Clozapine and risperidone were modeled together with their active metabolites, norclozapine and paliperidone, First, in PK‐Sim a rat PBPK model was developed and optimized using literature plasma PK data. Then, blood‐brain barrier parameters including the expression and efflux transport kinetics of P‐glycoprotein were optimized using literature microdialysis data on brain extracellular fluid (brainECF), which were further adapted when translating the rat PBPK model into the human PBPK model. Based on the simulated drug and metabolite concentrations in brainECF, drug‐D2 receptor binding kinetics (association and dissociation rates) were incorporated in MoBi to predict RO. From an extensive literature search, 32 plasma PK data sets (16 from rat and 16 from human studies) and 23 striatum RO data sets (13 from rat and 10 from human studies) were prepared and compared with the model predictions. The rat PBPK‐RO model adequately predicted the plasma concentrations of the parent drugs and metabolites and the RO levels. The human PBPK‐RO model also captured the plasma PK and RO levels despite the large interindividual and interstudy variability, although it tended to underestimate the plasma concentrations and RO measured at late time points after risperidone dosing. The developed human PBPK‐RO model was successfully applied to predict the plasma PK and RO changes observed after risperidone dose reduction in a clinical trial in schizophrenic patients.

Clozapine-Associated Pulmonary Embolism: A High-Mortality, Dose-Independent and Early-Onset Adverse Effect

BACKGROUND

Recent epidemiological studies have identified an excess of pulmonary embolism (PE) cases in patients treated with antipsychotic drugs. The findings are particularly relevant for patients treated with clozapine, which has many potentially life-threatening adverse drug effects. Among these adverse drug effects are myocarditis and agranulocytosis that have early onset and are dose independent, but also seizures and myocardial repolarization delay, which are dose dependent and may occur at any time. Together with death rates, these variables have important implications for clinical practice.

AREAS OF UNCERTAINTY

Study Question: What are the time of onset, dose relationship, and mortality of clozapine-associated PE?

DATA SOURCES

The published case reports of clozapine-associated PE were identified in a MEDLINE search. Cases occurring within 6 months of starting clozapine were considered to have early onset. Dosages of clozapine at the time of PE were defined as low (200 mg/d or less) or high (300 mg/d or greater). Patient outcome was divided into survival of the PE event and death.

RESULTS

The search identified 23 cases of clozapine-associated PE. The PE had early onset (6.4 ± 7.0 weeks) in 20 patients (87%, 95% confidence interval 67.9%-95.5%). PE occurred in 9 patients treated with low doses (152.8 ± 50.7 mg/d) and in 11 patients on high doses (372.7 ± 127.2 mg/d) of clozapine. Six patients (26.1%, 95% confidence interval 12.6%-46.5%) died.

CONCLUSIONS

A systematic review of the published case reports of clozapine-associated PE indicates that this adverse effect is highly lethal, has early onset and is dose independent. The findings should prompt careful monitoring and consideration of prophylactic treatment for venous thromboembolism for 6 months after starting treatment with clozapine.

Two cases of high serum clozapine concentrations occurring during inflammation in Chinese patients

Objective Serious infections or inflammations have been associated with serum clozapine concentration increases and sometimes with clozapine toxicity. Method These two cases describe Chinese patients (Case 1: a 57-year-old female nonsmoker with severe dermatitis and Case 2: a 47-year-old male nonsmoker with influenza and secondary infection). Results In both cases, the Drug Interaction Probability Scale established the presence of a probable drug-drug interaction. In both cases, the clozapine and the total clozapine concentration-to-dose ratios followed a temporal pattern (normal-high-normal), consistent with an inhibition of clozapine metabolism during peak inflammation. In the first case, the total clozapine concentration-to-dose ratio (8 with no/low inflammation: median of 3.10 and 2 at peak inflammation: median of 3.90) provided a significant difference (P = 0.044). In the second patient, because of the smaller sample size and reduced statistical power (4 with no infection: a median of 1.59 and 2 at peak infection: 3.46), the increase did not reach significance (P = 0.13). In the first case, the median baseline clozapine concentration-to-dose ratio increased by a factor of 1.45 from 2.00 to a peak of 2.89. To compensate for the inhibition of clozapine metabolism, the dose correction factor was 0.69 (1/1.45) or a decrease in dose of approximately one-third. In the second case, the median baseline clozapine concentration-to-dose ratio increased by a factor of 2.56 from 1.15 to a peak of 2.94. Conclusion This provided a dose correction factor of 0.40 (1/2.56) or approximately half the dose, similar to published cases in Caucasians with serious respiratory infections.