Neuropsychiatric Effects of Antimicrobial Agents

Fluoroquinolones-related psychiatric adverse events: a real‑world retrospective and pharmacovigilance database analysis

OBJECTIVE

The purpose of this study was to evaluate the pharmacovigilance and clinical characteristics of psychiatric adverse events(AEs) related to Fluoroquinolones(FQs), and to determine the risk factors for timely management.

METHODS

Data about AE reporting comes from the FDA Adverse Event Reporting System (FAERS) database, which was used for pharmacovigilance assessments. In addition, we also analyzed the cases of psychiatric AEs related to FQs retrospectively.

RESULTS

Both of the FAERS database analysis and literature reports show that the proportion of FQs-related psychiatric AEs reported in females were higher (51.11% VS 33.44% and 53.23% VS 46.77%). Both of them show that the proportion of psychiatric AEs caused by FQs was higher in the age groups of 19-44 (28.08% and 40.32%) and 45-64 (28.17% and 25.81%). Most psychiatric AEs occurred within 10 days after FQs administration. Literature shows that 67.74% of the psychiatric AEs disappeared within 3 days after drug withdrawal (some cases were accompanied by other drug).

CONCLUSION

Psychiatric AEs caused by FQs are serious, and there are many important safety signals that have not been mentioned in the label or previous studies. It is very important to identify and manage psychiatric AEs in time for the safe use of FQs.

Antibiotic-induced neuropsychiatric toxicity: epidemiology, mechanisms and management strategies - a narrative literature review

Antibiotics are amongst the most prescribed medications globally in both inpatient and outpatient settings. Antibiotic-induced neuropsychiatric toxicity is relatively uncommon; yet, when it occurs, it can lead to severe morbidity ranging from dizziness and confusion to seizure and psychosis. However, the actual incidence rate of these adverse events may be higher due to underdiagnosis or misdiagnosis as they are commonly confused with clinical manifestations of different neuropsychiatric conditions. The incidence and mechanism of antibiotic-induced neuropsychiatric toxicity vary between different antibiotic classes and clinical presentation (i.e. neurotoxicity versus psychiatric toxicity). However, the exact mechanism by which antibiotics can cause neuropsychiatric toxicity remains unclear. This article reviews the epidemiology of antibiotic-induced neuropsychiatric toxicity, explores potential mechanisms of this adverse event, investigates variations in frequency and clinical presentations between different antibiotic classes causing neuropsychiatric toxicity, and discusses management strategies.

Redesigning the kinetics of lysozyme amyloid aggregation by cephalosporin molecules

In lysozyme amyloidosis, fibrillar aggregates of lysozyme are associated with severe renal, hepatic, and gastrointestinal manifestations, with no definite therapy. Current drugs are now being tested in amyloidosis clinical trials as aggregation inhibitors to mitigate disease progression. The tetracycline group among antimicrobials in use is in phase II of clinical trials, whereas some macrolides and cephalosporins have shown neuroprotection. In the present study, two cephalosporins, ceftazidime (CZD) and cefotaxime (CXM), and a glycopeptide, vancomycin (VNC), are evaluated for inhibition of amyloid aggregation of hen egg white lysozyme (HEWL) under two conditions (i) 4 M guanidine hydrochloride (GuHCl) at pH 6.5 and 37° C, (ii) At pH 1.5 and 65 °C. Fluorescence quench titration and molecular docking methods report that CZD, CXM, and VNC interact more strongly with the partially folded intermediates (PFI) in comparison to the protein's natural state (N). However, only CZD and CXM proficiently inhibit the aggregation. Transmission electron microscopy, tinctorial assessments, and aggregation kinetics all support oligomer-level inhibition. Transition structures in CZD-HEWL and CXM-HEWL aggregation are shown by circular dichroism (CD). On the other hand, kinetic variables and soluble fraction assays point to a localized association of monomers. Intrinsic fluorescence (IF),1-Anilino 8-naphthalene sulphonic acid, and CD demonstrate structural and conformational modifications redesigning the PFI. GuHCl-induced unfolding and differential scanning fluorimetry suggested that the PFI monomers bound to CZD and CXM exhibited partial stability. Our results present two mechanisms that function in both solution conditions, creating a novel avenue for the screening of putative inhibitors for drug repurposing. We extend our proposed mechanisms in the designing of physical inhibitors of amyloid aggregation considering shorter time frames and foolproof methods.Communicated by Ramaswamy H. Sarma.

Antibiotic exposure is associated with decreased risk of psychiatric disorders

Objective: This study sought to investigate the relationship between antibiotic exposure and subsequent risk of psychiatric disorders. Methods: This retrospective cohort study used a national database of 69 million patients from 54 large healthcare organizations. We identified a cohort of 20,214 (42.5% male; 57.9 ± 15.1 years old [mean ± SD]) adults without prior neuropsychiatric diagnoses who received antibiotics during hospitalization. Matched controls included 41,555 (39.6% male; 57.3 ± 15.5 years old) hospitalized adults without antibiotic exposure. The two cohorts were balanced for potential confounders, including demographics and variables with potential to affect: the microbiome, mental health, medical comorbidity, and overall health status. Data were stratified by age and by sex, and outcome measures were assessed starting 6 months after hospital discharge. Results: Antibiotic exposure was consistently associated with a significant decrease in the risk of novel mood disorders and anxiety and stressor-related disorders in: men (mood (OR 0.84, 95% CI 0.77, 0.91), anxiety (OR 0.88, 95% CI 0.82, 0.95), women (mood (OR 0.94, 95% CI 0.89,1.00), anxiety (OR 0.93, 95% CI 0.88, 0.98), those who are 26-49 years old (mood (OR 0.87, 95% CI 0.80, 0.94), anxiety (OR 0.90, 95% CI 0.84, 0.97)), and in those ≥50 years old (mood (OR 0.91, 95% CI 0.86, 0.97), anxiety (OR 0.92, 95% CI 0.87, 0.97). Risk of intentional harm and suicidality was decreased in men (OR 0.73, 95% CI 0.55, 0.98) and in those ≥50 years old (OR 0.67, 95% CI 0.49, 0.92). Risk of psychotic disorders was also decreased in subjects ≥50 years old (OR 0.83, 95 CI: 0.69, 0.99). Conclusion: Use of antibiotics in the inpatient setting is associated with protective effects against multiple psychiatric outcomes in an age- and sex-dependent manner.

Cefaclor causes vagus nerve-mediated depression-like symptoms with gut dysbiosis in mice

Antibiotics are increasingly recognized as causing neuropsychiatric side effects including depression and anxiety. Alterations in central serotonin and 5-HT receptor expression are implicated in the pathogenesis of anxiety and depression, which are highly comorbid with gastrointestinal disorders. Nevertheless, it is still unclear how antibiotics can cause anxiety and depression. In this study, oral administration of cefaclor, a second-generation cephalosporin antibiotic, induced anxiety- and depression-like behaviors and colitis with gut microbiota alteration in mice. Cefaclor reduced serotonin levels and fluctuated 5-HT receptor mRNA expressions such as Htr1a, Htr1b, and Htr6 in the hippocampus. Vagotomy attenuated the cefaclor-induced anxiety- and depression-like symptoms, while the cefaclor-induced changes in gut bacteria alteration and colitis were not affected. Fluoxetine attenuated cefaclor-induced anxiety- and depression-like behaviors. Furthermore, fluoxetine decreased cefaclor-resistant Enterobacteriaceae and Enterococcaceae. Taken together, our findings suggest that the use of antibiotics, particularly, cefaclor may cause gut dysbiosis-dependent anxiety and depression through the microbiota-gut-blood-brain and microbiota-gut-vagus nerve-brain pathway. Targeting antibiotics-resistant pathogenic bacteria may be a promising therapeutic strategy for the treatment of anxiety and depression.

Depressive and Other Adverse CNS Effects of Fluoroquinolones

Fluoroquinolones (FQs) are widely used drugs around the world. This is a result of their broad spectrum of antibacterial activity, high bioavailability, and known efficacy. Since they appeared on the market, their prescribing frequency has gradually increased. In 2011, FQs became the third most prescribed class of antibiotics in the US. Widespread use of these drugs resulted in an increasing number of reported side effects. In 2016, the FDA warned about significant side effects, including mental disorders in the form of anxiety, psychotic symptoms, insomnia, and depression. Psychiatric adverse reactions to FQs occur with a frequency of 1 to 4.4% and the mechanism of their formation is not entirely clear. It is believed that the antagonistic effect of FQs on the GABA receptor or interaction with the main receptor for the glutamatergic system-NMDA-is responsible for this. The paper is a structured review of 68 selected publications and the latest summary of CNS adverse effects that occur during FQ use. Prescribers should be aware of the risk factors for FQ toxicity, including elderly patients with underlying medical conditions or receiving concomitant medication; however, these adverse events may also occur in other groups of patients.

Protocol for a feasibility randomized controlled trial to evaluate the efficacy, safety and tolerability of N-acetylcysteine in reducing adverse drug reactions among adults treated for multidrug-resistant tuberculosis in Tanzania

BACKGROUND

Adverse drug reactions (ADRs) frequently occur in patients using second-line anti-tuberculosis medicine for treatment of multidrug resistant tuberculosis (MDR-TB). ADRs contribute to treatment interruptions which can compromise treatment response and risk acquired drug resistance to critical newer drugs such as bedaquiline, while severe ADRs carry considerable morbidity and mortality. N-acetylcysteine (NAC) has shown promise in reducing ADRs for medications related to TB in case series or randomized controlled trials in other medical conditions, yet evidence is lacking in MDR-TB patients. TB endemic settings have limited capacity to conduct clinical trials. We designed a proof-of-concept clinical trial primarily to explore the preliminary evidence on the protective effect of NAC among people treated for MDR-TB with second-line anti-TB medications.

METHODS

This is a proof-of-concept randomized open label clinical trial with 3 treatment arms including a control arm, an interventional arm of NAC 900 mg daily, and an interventional arm of NAC 900 mg twice-daily administered during the intensive phase of MDR-TB treatment. Patients initiating MDR-TB treatment will be enrolled at Kibong'oto National Center of Excellence for MDR-TB in the Kilimanjaro region of Tanzania. The minimum anticipated sample size is 66; with 22 participants in each arm. ADR monitoring will be performed at baseline and daily follow-up over 24 weeks including blood and urine specimen collection for hepatic and renal function and electrolyte abnormalities, and electrocardiogram. Sputum will be collected at baseline and monthly thereafter and cultured for mycobacteria as well as assayed for other molecular targets of Mycobacterium tuberculosis. Adverse drug events will be analysed over time using mixed effect models. Mean differences between arms in change of the ADRs from baseline (with 95% confidence intervals) will be derived from the fitted model.

DISCUSSION

Given that NAC promotes synthesis of glutathione, an intracellular antioxidant that combats the impact of oxidative stress, it may protect against medication induced oxidative damage in organs such as liver, pancreas, kidney, and cells of the immune system. This randomized controlled trial will determine if NAC leads to fewer ADRs, and if this protection is dose dependent. Fewer ADRs among patients treated with MDR-TB may significantly improve treatment outcomes for multidrug regimens that necessitate prolonged treatment durations. Conduct of this trial will set the needed infrastructure for clinical trials.

TRIAL REGISTRATION

PACTR202007736854169 Registered 03 July 2020.

Safety and Tolerability of Antimicrobial Agents in the Older Patient

Older patients are at high risk of infections, which often present atypically and are associated with high morbidity and mortality. Antimicrobial treatment in older individuals with infectious diseases represents a clinical challenge, causing an increasing burden on worldwide healthcare systems; immunosenescence and the coexistence of multiple comorbidities determine complex polypharmacy regimens with an increase in drug-drug interactions and spread of multidrug-resistance infections. Aging-induced pharmacokinetic and pharmacodynamic changes can additionally increase the risk of inappropriate drug dosing, with underexposure that is associated with antimicrobial resistance and overexposure that may lead to adverse effects and poor adherence because of low tolerability. These issues need to be considered when starting antimicrobial prescriptions. National and international efforts have been made towards the implementation of antimicrobial stewardship (AMS) interventions to help clinicians improve the appropriateness and safety of antimicrobial prescriptions in both acute and long-term care settings. AMS programs were shown to decrease consumption of antimicrobials and to improve safety in hospitalized patients and older nursing home residents. With the abundance of antimicrobial prescriptions and the recent emergence of multidrug resistant pathogens, an in-depth review of antimicrobial prescriptions in geriatric clinical practice is needed. This review will discuss the special considerations for older individuals needing antimicrobials, including risk factors that shape risk profiles in geriatric populations as well as an evidence-based description of antimicrobial-induced adverse events in this patient population. It will highlight agents of concern for this age group and discuss interventions to mitigate the effects of inappropriate antimicrobial prescribing.

Antibiotics and mental health: The good, the bad and the ugly

Antibiotics are recognised as, on occasion, producing psychiatric side effects, most notably depression and anxiety. Apart from antimicrobial activity, antibiotics have multiple off-target effects. The brain-gut-microbiota axis has multiple sites for off-target activity, which may produce either positive or negative antibiotic effects. Here we review how antibiotics impact mental health by acting through the brain-gut-microbiota axis. Microbes in the gut influence brain function by acting through the vagus nerve or by altering the production of short-chain fatty acids or the amino acid tryptophan, the building block of serotonin. Not all antimicrobial actions of antibiotics have a negative impact. The first antidepressant discovered was actually an antibiotic: isoniazid is an antibacterial drug developed for treating tuberculosis. Minocycline, which enters the brain and mediates its effects through microglia, shows antidepressant activity. Some antibiotics bring about a significant decrease in gut microbial diversity, and this is viewed as a risk factor for depression. Other risk factors induced by antibiotics include altered gut barrier function, activation of the hypothalamic-pituitary-adrenal axis, reducing levels of brain-derived neurotrophic factor or oxytocin and alteration of vagal tone. Although most patients taking antibiotics do not suffer from an iatrogenic psychiatric disorder, some do. As clinicians, we need to keep this in mind. The development of new antibiotics is primarily focused on antibiotic resistance, but efforts should be made to reduce off-target brain-gut-microbiota effects resulting in mental health problems.

Delirium associated with the use of macrolide antibiotics: a review

OBJECTIVE

This review aimed to explore and summarise available cases of delirium suspected to be associated with the use of macrolide antibiotics reported in the literature and the United States Food and Drug Administration's Adverse Event Reporting System (FAERS) database.

METHODS

Electronic searches of the literature were conducted in four online databases: PubMed/MEDLINE, Scopus, Web of Science and Serbian Citation Index (SCIndeks). A search of FAERS database was also conducted to supplement the findings of the literature search. Descriptive statistics, narrative summation and tabulation of the extracted data were made.

RESULTS

Cases of delirium which satisfied inclusion criteria were found for clarithromycin, azithromycin, erythromycin and telithromycin. Delirium was described in patients of various age groups, including children. Drug-drug interactions may have contributed to its occurrence in some of the cases. Average time to onset of delirium was 2.5 days for azithromycin and 3.3 days for clarithromycin.

CONCLUSIONS

Considering that these drugs may be a possible cause of delirium, clinicians should be aware that timely recognition of this possible side effect can lead to earlier discontinuation of the culprit drug, reduce time spent in a delirious state and improve patients' outcomes.KEY POINTSCases of delirium which satisfied inclusion criteria were found for clarithromycin, azithromycin, erythromycin and telithromycin.Cases of delirium were described in patients of various age groups, including children.Drug-drug interactions may have contributed to the occurrence of delirium in some of the cases.Time to onset of delirium ranged from 2 to 3.5 days (mean: 2.5 days) for azithromycin and from 1 to 7 days (mean: 3.3 days) for clarithromycin.Cessation of the macrolide antibiotic seems to be the best management strategy, although some of the patients may, in addition, require antipsychotics.

A VigiBase Descriptive Study of Fluoroquinolone-Associated Peripheral Nervous System Disorders

BACKGROUND

Recent drug safety concerns described fluoroquinolone (FQ)-induced peripheral nervous system reactions. The objective of this study was to characterize such reports from VigiBase.

METHODS

The analysis included FQ-induced peripheral nervous system disorder adverse drug reaction (ADR) reports (up to July 2019). We looked into the disproportionality data in terms of proportional reporting ratio (PRR) and information component (IC) values, and descriptive analysis was performed for FQ-ADRs positive associations (ADRs, suspected FQs, potential risk factors, such as associated therapy and underlying disease).

RESULTS

Disproportionality analysis revealed 4374 reports (3531 serious) with peripheral nervous system ADRs associated with at least three FQs (neuropathy peripheral, 5492; neuralgia, 481; polyneuropathy, 220; sensory loss, 99; peripheral sensorimotor neuropathy, 39). Among these, both time-to-onset and duration of reaction were mostly between 1-7 days and ≥30 days. Most of the ADRs were not recovered/resolved at the time of reporting.

CONCLUSION

The results augment the existing data on FQ safety concerns, specifically their potential effect on the nervous system.

Antibiotics and the Nervous System-Which Face of Antibiotic Therapy Is Real, Dr. Jekyll (Neurotoxicity) or Mr. Hyde (Neuroprotection)?

Antibiotics as antibacterial drugs have saved many lives, but have also become a victim of their own success. Their widespread abuse reduces their anti-infective effectiveness and causes the development of bacterial resistance. Moreover, irrational antibiotic therapy contributes to gastrointestinal dysbiosis, that increases the risk of the development of many diseases, including neurological and psychiatric. One of the potential options for restoring homeostasis is the use of oral antibiotics that are poorly absorbed from the gastrointestinal tract (e.g., rifaximin alfa). Thus, antibiotic therapy may exert neurological or psychiatric adverse drug reactions which are often considered to be overlooked and undervalued issues. Drug-induced neurotoxicity is mostly observed after beta-lactams and quinolones. Penicillin may produce a wide range of neurological dysfunctions, including encephalopathy, behavioral changes, myoclonus or seizures. Their pathomechanism results from the disturbances of gamma-aminobutyric acid-GABA transmission (due to the molecular similarities between the structure of the β-lactam ring and GABA molecule) and impairment of the functioning of benzodiazepine receptors (BZD). However, on the other hand, antibiotics have also been studied for their neuroprotective properties in the treatment of neurodegenerative and neuroinflammatory processes (e.g., Alzheimer's or Parkinson's diseases). Antibiotics may, therefore, become promising elements of multi-targeted therapy for these entities.

Doxycycline exposure during adolescence and future risk of non-affective psychosis and bipolar disorder: a total population cohort study

Doxycycline has been hypothesized to prevent development of severe mental illness (SMI) through the suppression of microglia, especially if administered during the intense synaptic pruning period of adolescence. However, results from register studies on potential benefits differ considerably. The aim of the present study was to determine whether doxycycline exposure during adolescence is associated with reduced SMI risk, and to investigate if a direct and specific causality is plausible. This is a Swedish national population register-based cohort study of all individuals born from 1993 to 1997, followed from the age of 13 until end of study at the end of 2016. The primary exposure was cumulative doxycycline prescription ≥3000 mg and outcomes were first diagnosis of non-affective psychosis (F20-F29) and first diagnosis of bipolar disorder (F30-F31). Causal effects were explored through Cox regressions with relevant covariates and secondary analyses of multilevel exposure and comparison to other antibiotics. We found no association between doxycycline exposure and risk of subsequent non-affective psychosis (adjusted hazard ratio (HR) 1.15, 95% CI 0.73-1.81, p = 0.541) and an increased risk of subsequent bipolar disorder (adjusted HR 1.95, 95% CI 1.49-2.55, p < 0.001). We do not believe the association between doxycycline and bipolar disorder is causal as similar associations were observed for other common antibiotics.

Infections, antibiotic treatment and the Microbiome in relation to schizophrenia

Schizophrenia is a heterogeneous disorder with several potential pathophysiological mechanisms, including immune activation. Infections have been identified as a significant contributing risk factor for schizophrenia; this association is reviewed together with the potential impact of antibiotic treatment and alterations of the intestinal microbiota. Both infections and the treatment with antibiotics may alter the composition of the gut microbiota, causing dysbiosis, which in animal studies has been associated with alterations of behavior. Of the few studies that have been conducted on humans, some have suggested alterations in the microbial composition of individuals with schizophrenia compared to healthy controls, albeit with conflicting results. Recently, increased attention has emerged regarding potential adverse effects from antibiotics, as a number of these have been associated with an increased risk of psychotic episodes. Particularly, the fluoroquinolones have been associated with neurotoxic adverse events. The association between schizophrenia and infections, antibiotic treatment and dysbiosis, may be an epiphenomenon, which could be explained by other confounding factors. However, these associations could be causal and could therefore be important risk factors in a subgroup of patients. Large-scale well-matched longitudinal studies are needed with measurements of immune markers from multiple biological samples, ranging from material close to the brain, as cerebrospinal fluid and brain-scans targeting neuroinflammation, to analysis of blood and intestinal microbiota. This would help to obtain more definite results on the association between infections, immune components and microbiota alterations in relation to schizophrenia.

Macrolide-associated ototoxicity: a cross-sectional and longitudinal study to assess the association of macrolide use with tinnitus and hearing loss

BACKGROUND

Macrolides are widely prescribed antibiotics for many different indications. However, there are concerns about adverse effects such as ototoxicity.

OBJECTIVES

To investigate whether macrolide use is associated with tinnitus and hearing loss in the general population.

METHODS

Cross-sectional (n = 4286) and longitudinal (n = 636) analyses were performed within the population-based Rotterdam Study. We investigated with multivariable logistic regression models the association between macrolides and tinnitus, and with multivariable linear regression models the association between macrolides and two different hearing thresholds (both ears, averaged over 0.25, 0.5, 1, 2, 4 and 8 kHz and 2, 4 and 8 kHz). Both regression models were adjusted for age, sex, systolic blood pressure, alcohol, smoking, BMI, diabetes, education level, estimated glomerular filtration rate and other ototoxic or tinnitus-generating drugs. Cumulative exposure to macrolides was categorized according to the number of dispensed DDDs and duration of action.

RESULTS

In the fully adjusted model, ever use of macrolides was associated with a 25% higher likelihood of prevalent tinnitus (OR = 1.25; 95% CI 1.07-1.46). This association was more prominent in participants with a cumulative dose of more than 14 DDDs and among users of intermediate- or long-acting macrolides. Macrolide use in between both assessments was associated with more than a 2-fold increased risk on incident tinnitus. No general association between macrolides and hearing loss was observed. A borderline significant higher hearing threshold in very recent users (≤3 weeks) was found.

CONCLUSIONS

Macrolide use was significantly associated with both prevalent and incident tinnitus. Macrolide-associated tinnitus was likely cumulative dose-dependent.

Ceftazidime-Induced Neurotoxicity in an 80-Year-Old Female With Renal Dysfunction: A Case Report

Neurological toxicity is a relatively rare adverse reaction reported in elderly patients treated with cephalosporins. We present a case of ceftazidime-induced encephalopathy in the context of acute kidney injury in an 80-year-old female treated for a Pseudomonas aeruginosa prosthetic joint infection. During the course of treatment, the patient developed sudden confusion and disorientation. The patient's mental state progressively worsened, eventually leading to intubation and admission to the intensive care unit. As imaging and laboratory analyses revealed no alternative causes explaining the patient's symptoms, ceftazidime was stopped under the suspicion of drug-induced neurotoxicity. Shortly after ceftazidime discontinuation, the patient's condition drastically improved and returned to baseline within 5 days. This case reveals the potential severity of cephalosporin-induced neurotoxicity in elderly patients and highlights the importance of quickly detecting such adverse events in order to prevent dire outcomes.

Directly and Indirectly Targeting the Glycine Modulatory Site to Modulate NMDA Receptor Function to Address Unmet Medical Needs of Patients With Schizophrenia

Schizophrenia is a severe mental illness that affects ~1% of the world's population. It is clinically characterized by positive, negative, and cognitive symptoms. Currently available antipsychotic medications are relatively ineffective in improving negative and cognitive deficits, which are related to a patient's functional outcomes and quality of life. Negative symptoms and cognitive deficits are unmet by the antipsychotic medications developed to date. In recent decades, compelling animal and clinical studies have supported the NMDA receptor (NMDAR) hypofunction hypothesis of schizophrenia and have suggested some promising therapeutic agents. Notably, several NMDAR-enhancing agents, especially those that function through the glycine modulatory site (GMS) of NMDAR, cause significant reduction in psychotic and cognitive symptoms in patients with schizophrenia. Given that the NMDAR-mediated signaling pathway has been implicated in cognitive/social functions and that GMS is a potential therapeutic target for enhancing the activation of NMDARs, there is great interest in investigating the effects of direct and indirect GMS modulators and their therapeutic potential. In this review, we focus on describing preclinical and clinical studies of direct and indirect GMS modulators in the treatment of schizophrenia, including glycine, D-cycloserine, D-serine, glycine transporter 1 (GlyT1) inhibitors, and D-amino acid oxidase (DAO or DAAO) inhibitors. We highlight some of the most promising recently developed pharmacological compounds designed to either directly or indirectly target GMS and thus augment NMDAR function to treat the cognitive and negative symptoms of schizophrenia. Overall, the current findings suggest that indirectly targeting of GMS appears to be more beneficial and leads to less adverse effects than direct targeting of GMS to modulate NMDAR functions. Indirect GMS modulators, especially GlyT1 inhibitors and DAO inhibitors, open new avenues for the treatment of unmet medical needs for patients with schizophrenia.

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.

Psychosis as an adverse effect of antibiotics

Adverse neuropsychiatric effects of antibiotic medications have been well documented. There is evidence suggesting a direct relationship between acute psychosis and antibiotic exposure. Conversely, the tetracycline antibiotic minocycline has been associated with improvements in psychopathology in patients with psychotic disorders. The purpose of the present study was to investigate the prevalence of spontaneously reported adverse drug reactions (ADRs) of psychotic symptoms in adults for antibiotics and the odds of psychosis compared to minocycline for individual antibiotics and antibiotic classes. We searched the publicly available U.S. F.D.A. Adverse Event Reporting System (FAERS) from inception through March 2020 for which an antibiotic was the suspected agent of an adverse drug reaction (ADR). We investigated 23 different antibiotics, comprising 183,265 adverse event reports and 2955 psychosis ADRs. For individual antibiotics, the prevalence of psychosis ADRs ranged from 0.3 to 3.8%. Fifteen antibiotics were associated with a significantly increased odds of psychosis (OR ​= ​1.67-9.48), including penicillins, fluoroquinolones, macrolides, cephalosporins, and doxycycline. Our results suggest that psychosis is a potential adverse effect of antibiotic treatment, but risks vary by specific agents. Future studies in this area are needed to identify specific underlying biological mechanisms that contribute to these associations. Findings may also inform on clinical decisions regarding the selection of antibiotic therapy in vulnerable patient populations.

Integrating Genome-Wide Association Studies and Gene Expression Profiles With Chemical-Genes Interaction Networks to Identify Chemicals Associated With Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and has the second highest mortality rate in global cancer. Exploring the associations between chemicals and CRC has great significance in prophylaxis and therapy of tumor diseases. This study aims to explore the relationships between CRC and environmental chemicals on genetic basis by bioinformatics analysis. The genome-wide association study (GWAS) datasets for CRC were obtained from the UK Biobank. The GWAS data for colon cancer (category C18) includes 2,581 individuals and 449,683 controls, while that of rectal cancer (category C20) includes 1,244 individuals and 451,020 controls. In addition, we derived CRC gene expression datasets from the NCBI-GEO (GSE106582). The chemicals related gene sets were acquired from the comparative toxicogenomics database (CTD). Transcriptome-wide association study (TWAS) analysis was applied to CRC GWAS summary data and calculated the expression association testing statistics by FUSION software. We performed chemicals related gene set enrichment analysis (GSEA) by integrating GWAS summary data, mRNA expression profiles of CRC and the CTD chemical-gene interaction networks to identify relationships between chemicals and genes of CRC. We observed several significant correlations between chemicals and CRC. Meanwhile, we also detected 5 common chemicals between colon and rectal cancer, including methylnitronitrosoguanidine, isoniazid, PD 0325901, sulindac sulfide, and importazole. Our study performed TWAS and GSEA analysis, linked prior knowledge to newly generated data and thereby helped identifying chemicals related to tumor genes, which provides new clues for revealing the associations between environmental chemicals and cancer.

Assessing the association between fluoroquinolones and emerging adverse drug reactions raised by regulatory agencies: An umbrella review

BACKGROUND

Regulatory agencies warned against fluoroquinolones for the management of minor infections because of the risk of emerging adverse events (collagen-associated adverse events, neuropsychiatric toxicity and long-term disability). We aimed to assess quality and credibility of evidence as well as causality regarding these putative associations.

METHODS

MEDLINE, Scopus, Web of Science and PROSPERO were searched, from inception to August 2019, for systematic reviews with meta-analyses investigating emerging adverse events. Two investigators extracted data to grade quality (through validated AMSTAR-2 tool), rank credibility of the evidence (convincing, highly suggestive, suggestive, weak) through adapted criteria including E-value calculation, and assess causality (Hill's criteria).

RESULTS

Seven systematic reviews of observational studies providing 16 risk estimates [seven, five and four, respectively, for aortic aneurysm/dissection (AAD), retinal detachment (RD) and any tendon disorders (ATD)] met inclusion criteria. No systematic reviews with meta-analysis investigating the risk of neuropsychiatric toxicity or long-term disability were found. The associations between fluoroquinolones and AAD/ATD showed highly suggestive credibility and were supported by strong evidence of causality (double increased risk, especially within first 2 months of treatment). Conflicting data concerning the emergence of RD were retrieved, resulting in weak evidence of causality. Quality of the evidence ranged from high to low for AAD, from moderate to critically low for RD, and it was moderate for ATD.

CONCLUSION

Our analysis supports credible, plausible and highly suggestive associations with AAD (rare occurrence but strong causality) and ATD. Limitations of both umbrella reviews and observational evidence should be considered.

Delirium induced by tigecycline treatment for Acinetobacter baumannii infection: A case report

RATIONALE

Tigecycline is a broad-spectrum antimicrobial agent structurally belong to tetracyclines and covers against many multidrug-resistant organisms. Arising clinical cases reporting its adverse drug reactions have emerged alongside with the increasing off label use globally. By literature review, delirium caused by tigecycline has not been reported yet. We present what we believe to be the first case of tigecycline-induced delirium.

PATIENT CONCERNS

A 77-year-old male patient with end-stage renal disease was hospitalized due to acute exacerbation of chronic obstructive pulmonary disease.

DIAGNOSIS

The patient developed delirium after infused with a loading dose of tigecycline for pulmonary infection.

INTERVENTIONS

All potential causes inducing delirium were evaluated and the symptoms improved soon after discontinuation of tigecycline. He experienced delirium once again after reusing tigecycline for the exacerbation of the pulmonary infection even without a loading dose. Tigecycline was discontinued and the symptoms quickly relieved.

OUTCOMES

According to the Naranjo adverse drug reaction probability scale, tigecycline was the probable cause of his delirium.

LESSONS

Clinicians should be aware of this potential adverse effect of tigecycline. We recommend that clinicians monitor patients for signs and symptoms of delirium during treatment with tigecycline.

Repurposing antitubercular agent isoniazid for treatment of prostate cancer

The development of versatile antitumor agents with tumor-imaging, targeting and therapeutic activity is promising for clinical cancer therapy. Prostate cancer is still the one of the leading threats to males. Current therapies have restricted clinical efficiency for patients with advanced and metastatic prostate cancer. Recent studies demonstrate that monoamine oxidase A (MAOA) levels elevate with prostate cancer aggression and metastasis. In addition, MAOA inhibitor therapies have been reported as an effective means to reduce the metastasis of prostate cancer and extend mouse survival. Thus, these findings provide evidence that MAOA is promising for the treatment of metastatic and advanced prostate cancer. Herein, three isoniazid (INH)-dye conjugates were synthesized by conjugating MAOA inhibitor INH with mitochondria-targeting NIRF heptamethine dyes to improve the therapeutic efficacy of prostate cancer. These INH-dye conjugates could accumulate in PC-3 cellular mitochondria via organic anion transport peptide (OATP), increase ROS generation, and induce cancer cells apoptosis. In prostate cancer bearing xenografts, INH-dye conjugates showed significantly improved tumor-homing characteristics, resulting in potent antitumor activity via a reduction in MAOA activity. These results suggest that INH-dye conjugates have great potential to be used as versatile antitumor agents with prostate cancer targeting, NIR imaging, and potent antitumor efficacy.

Antibiotics and the nervous system: More than just the microbes?

The use of antibiotics has recently risen to prominence in neuroscience due to their potential value in studying the microbiota-gut-brain axis. In this context they have been largely employed to illustrate the many influences of the gut microbiota on brain function and behaviour. Much of this research is bolstered by the abnormal behaviour seen in germ-free animals and other well-controlled experiments. However, this literature has largely failed to consider the neuroactive potential of antibiotics themselves, independent from, or in addition to, their microbicidal effects. This is problematic, as clinical as well as experimental literature, largely neglected through the past decade, has clearly demonstrated that broad classes of antibiotics are neuroactive or neurotoxic. This is true even for some antibiotics that are widely regarded as not absorbed in the intestinal tract, and is especially concerning when considering the highly-concentrated and widely-ranging doses that have been used. In this review we will critically survey the clinical and experimental evidence that antibiotics may influence a variety of nervous system functions, from the enteric nervous system through to the brain and resultant behaviour. We will discuss substantial evidence which clearly suggests neuro-activity or -toxicity by most classes of antibiotics. We will conclude that, while evidence for the microbiota-gut-brain axis remains strong, clinical and experimental studies which employ antibiotics to probe it must consider this potential confound.

Prevalence of Comorbid Chronic Obstructive Pulmonary Disease in Individuals Suffering from Schizophrenia and Bipolar Disorder: A Systematic Review

The disease burden associated with schizophrenia and bipolar disorder is substantial, with affected individuals having a shorter life expectancy and a high risk of severe physical comorbid conditions. These individuals are more likely to smoke and have a longer smoking history compared to the general population. Furthermore, use of antipsychotic drugs has also been linked to active smoking. Chronic obstructive pulmonary disease (COPD) is a respiratory condition affecting elderly individuals with a long smoking history, so it would be expected that individuals suffering from major mental disorders may exhibit a higher prevalence of COPD compared to the general population. We searched the databases Pubmed and Scopus for observational studies of at least 200 patients including at least one group suffering from schizophrenia or bipolar disorder and a comparison group of individuals at risk of COPD. The initial search, along with the data extraction process and the risk of bias assessment were carried out independently by the two reviewers. Eight studies were included. The risk of bias was substantial as most studies did not adequately address confounding variables. A pooled analysis showed a greater likelihood of suffering from comorbid COPD compared with the general population both for schizophrenic (OR 1.573, 1.439-1.720) and bipolar individuals (OR 1.551, 1.452-1.658). Based on these findings, COPD is more common in individuals suffering from major mental illness compared to the general population. Further research is required to ascertain whether smoking is the only cause and develop strategies for the prevention of COPD in these high-risk groups.

Discontinuation of dolutegravir, elvitegravir/cobicistat and raltegravir because of toxicity in a prospective cohort

OBJECTIVES

The aim of the study was to assess the rates of discontinuation of integrase inhibitor regimens because of any neuropsychiatric adverse event (NPAE) and the factors associated with discontinuation.

METHODS

A population-based, prospective, multicentre cohort study was carried out. Treatment-naïve subjects starting therapy with a regimen containing integrase inhibitors, or those switching to such a regimen, with plasma HIV-1 RNA < 50 HIV-1 RNA copies/mL in 14 hospitals in Catalonia or the Balearic Islands (Spain) were included in the study. Every discontinuation because of adverse events (AEs) was double-checked directly with treating physicians. Multivariable Cox models identified factors correlated with discontinuation.

RESULTS

A total of 4165 subjects (37% treatment-naïve) started regimens containing dolutegravir (n = 1650; 91% with abacavir), raltegravir (n = 930) or elvitegravir/cobicistat (n = 1585). There were no significant differences among regimens in the rate of discontinuation because of any AE. Rates of discontinuation because of NPAEs were low but higher for dolutegravir/abacavir/lamivudine [2.1%; 2.9 (95% confidence interval (CI) 2.0, 4.2) discontinuations/100 patients/year] versus elvitegravir/cobicistat (0.5%; 0.8 (95% CI 0.3, 1.5) discontinuations/100 patients/year], with significant differences among centres for dolutegravir/abacavir/lamivudine and NPAEs (P = 0.003). We identified an association of female gender and lower CD4 count with increased risk of discontinuation because of any AE [Incidence ratio (IR) 2.3 (95% CI 1.4, 4.0) and 1.8 (95% CI 1.1, 2.8), respectively]. Female gender, age > 60 years and abacavir use were not associated with NPAE discontinuations. NPAEs were commonly grade 1-2, and had been present before and improved after drug withdrawal.

CONCLUSIONS

In this large prospective cohort study, patients receiving dolutegravir, raltegravir or elvitegravir/cobicistat did not show significant differences in the rate of discontinuation because of any toxicity. The rate of discontinuations because of NPAEs was low, but was significantly higher for dolutegravir than for elvitegravir/cobicistat, with significant differences among centres, suggesting that greater predisposition to believe that a given adverse event is caused by a given drug of some treating physicians might play a role in the discordance seen between cohorts.

Construction of an overexpression library for Mycobacterium tuberculosis

There is a pressing need to develop novel anti-tubercular drugs. High-throughput phenotypic screening yields chemical series that inhibit bacterial growth. Target identification for such series is challenging, but necessary for optimization of target engagement and the development of series into clinical drugs. We constructed a library of recombinant Mycobacterium tuberculosis strains each expressing a single protein from an inducible promoter as a tool for target identification. The library of 1733 clones was arrayed in 96-well plates for rapid screening and monitoring growth. The library contains the majority of the annotated essential genes as well as genes involved in cell wall and fatty acid biosynthesis, virulence factors, regulatory proteins, efflux, and respiration pathways. We evaluated the growth kinetics and plasmid stability over three passages for each clone in the library. We determined expression levels (mRNA and/or protein) in 396 selected clones. We screened the entire library and identified the Alr-expressing clone as the only recombinant strain, which grew in the presence of d-cycloserine (DCS). We confirmed that the Alr-expressing clone was resistant to DCS (7-fold shift in minimum inhibitory concentration). The library represents a new tool that can be used to screen for compound resistance and other phenotypes.