Biological substantiation of antipsychotic-associated pneumonia: Systematic literature review and computational analyses

Clozapine and Pneumonia: Synthesizing the Link by Reviewing Existing Reports-A Systematic Review and Meta-Analysis

Background and Objectives: Clozapine is a highly effective antipsychotic used for treating treatment-refractory psychotic and mood disorders. However, clozapine also has a serious risk of side effects leading to mortality, particularly its potentiated risk of leading to pneumonia. This review aims to overview the demographic and health-related risk factors leading to pneumonia to better inform risk assessment for clozapine users and to summarise current theories on the mechanisms for clozapine-associated pneumonia. This paper will highlight the need to prioritise pneumococcal vaccination in this population group. Materials and Method: We conducted a literary search of five online databases conforming to PRISMA. Our review includes all peer-reviewed papers with original data that discuss clozapine and pneumonia and excludes case reports. Baseline information of participants, pneumonia-related information and information regarding risk factors and mechanisms causing pneumonia were also extracted. Results: Clozapine was found to have an increased risk of pneumonia compared to other antipsychotic medications. Factors included comorbidities, higher clozapine dosages, and concurrent use of other antipsychotic medications. Key mechanisms for clozapine-associated pneumonia include clozapine-induced hyper sedation, sialorrhea and neutropoenia. Conclusions: While clozapine improves overall mortality for patients, our review confirms clozapine has the highest risk of pneumonia of all antipsychotics. The review also highlights the prevalent underuse of pneumococcal vaccines among clozapine users and the urgent need to increase uptake.

Investigating in VigiBase over 6000 cases of pneumonia in clozapine-treated patients in the context of the literature: focus on high lethality and the association with aspiration pneumonia

BACKGROUND

The literature associates clozapine with pneumonia/aspiration pneumonia.

RESEARCH DESIGN AND METHODS

The international pharmacovigilance database (VigiBase™) uses the information component (IC) as statistical signal. VigiBase clozapine reports were analyzed for pneumonia/aspiration pneumonia from introduction to 10 May 2023.

RESULTS

There were 6392 cases of all types of pneumonia (5572 cases of pneumonia, 775 of aspiration pneumonia, and 45 combined). The IC was 3.52 for aspiration pneumonia, introduced as a VigiBase label in 2003, and 1.91 for pneumonia. Patients were reclassified as 3628 with no signs of aspiration and 1533 with signs. Signs of aspiration were strongly associated with some co-medications: olanzapine, odds ratio (OR) = 23.8, 95% confidence interval (CI), 14.9-38.0; risperidone OR = 18.6, CI, 11.4-30.4; valproic acid, OR = 5.5, CI, 4.5-6.6; and benzodiazepines OR = 5.5, CI, 4.5-6.6. In 2415 cases with completed data, fatal outcomes made up 45% (signs of aspiration made no difference), but there was wide variability from 0% (females <45 years of age; duration ≤30 days) to 76% (males >64 years of age; duration >1 year). During the first week, pneumonia was associated with 1) very high titration doses, 2) very small doses in Parkinson's disease, and 3) Japan vs other countries.

CONCLUSIONS

In clozapine-treated patients: 1) at least 30% of pneumonia cases may be aspiration pneumonia, 2) stopping some co-medications may decrease the risk of aspiration pneumonia, 3) average lethality in pneumonia was 45% but may be around 75% in geriatric patients with long-term treatment, and 4) safer titrations may sometimes require 5-mg tablets.

Multiple adverse outcomes associated with antipsychotic use in people with dementia: population based matched cohort study

OBJECTIVE

To investigate risks of multiple adverse outcomes associated with use of antipsychotics in people with dementia.

DESIGN

Population based matched cohort study.

SETTING

Linked primary care, hospital and mortality data from Clinical Practice Research Datalink (CPRD), England.

POPULATION

Adults (≥50 years) with a diagnosis of dementia between 1 January 1998 and 31 May 2018 (n=173 910, 63.0% women). Each new antipsychotic user (n=35 339, 62.5% women) was matched with up to 15 non-users using incidence density sampling.

MAIN OUTCOME MEASURES

The main outcomes were stroke, venous thromboembolism, myocardial infarction, heart failure, ventricular arrhythmia, fracture, pneumonia, and acute kidney injury, stratified by periods of antipsychotic use, with absolute risks calculated using cumulative incidence in antipsychotic users versus matched comparators. An unrelated (negative control) outcome of appendicitis and cholecystitis combined was also investigated to detect potential unmeasured confounding.

RESULTS

Compared with non-use, any antipsychotic use was associated with increased risks of all outcomes, except ventricular arrhythmia. Current use (90 days after a prescription) was associated with elevated risks of pneumonia (hazard ratio 2.19, 95% confidence interval (CI) 2.10 to 2.28), acute kidney injury (1.72, 1.61 to 1.84), venous thromboembolism (1.62, 1.46 to 1.80), stroke (1.61, 1.52 to 1.71), fracture (1.43, 1.35 to 1.52), myocardial infarction (1.28, 1.15 to 1.42), and heart failure (1.27, 1.18 to 1.37). No increased risks were observed for the negative control outcome (appendicitis and cholecystitis). In the 90 days after drug initiation, the cumulative incidence of pneumonia among antipsychotic users was 4.48% (4.26% to 4.71%) versus 1.49% (1.45% to 1.53%) in the matched cohort of non-users (difference 2.99%, 95% CI 2.77% to 3.22%).

CONCLUSIONS

Antipsychotic use compared with non-use in adults with dementia was associated with increased risks of stroke, venous thromboembolism, myocardial infarction, heart failure, fracture, pneumonia, and acute kidney injury, but not ventricular arrhythmia. The range of adverse outcomes was wider than previously highlighted in regulatory alerts, with the highest risks soon after initiation of treatment.

Integrated analysis of the lncRNA-associated competing endogenous RNA network in salt sensitivity of blood pressure

Accumulating evidence showed that competing endogenous RNA (ceRNA) mechanism plays a pivotal role in salt sensitivity of blood pressure (SSBP). We constructed a ceRNA network based on SSBP-related differently expressed lncRNAs (2), mRNAs (73) and miRNAs (18). Bioinformatic analyses were utilized to analyze network and found network genes participate in biological pathways related to SSBP pathogenesis such as regulation of nitric oxide biosynthetic process (GO:0045,428) and cellular response to cytokine stimulus (GO:0071,345). Fourteen candidate ceRNA pathways were selected from network to perform qRT-PCR validation and found nine RNAs (KCNQ1OT1, SLC8A1-AS1, IL1B, BCL2L11, KCNJ15, CX3CR1, KLF2, hsa-miR-362-5p and hsa-miR-423-5p) differently expressed between salt-sensitive (SS) and salt-resistant (SR) groups (P < 0.05). Four ceRNA pathways were further validated by luciferase reporter assay and found KCNQ1OT1→hsa-miR-362-5p/hsa-miR-423-5p→IL1B pathways may influence the pathogenic mechanism of SS. Our findings suggested the ceRNA pathway and network may affect SS occurrence mainly through endothelial dysfunction and inflammatory activation.

A case-control study of antipsychotic use and pneumonia-related mortality in the United Kingdom

BACKGROUND AND AIM

There is increasing evidence linking antipsychotic use with pneumonia, but limited evidence of an effect on pneumonia-related outcomes such as mortality. In this study, we aimed to examine the association of pneumonia-related death with specific antipsychotic exposure.

METHOD

Deaths analysed were those reported to a UK-based drug-related deaths database, the National Programme on Substance Abuse Deaths (NPSAD), between 1997 and September 2020. We conducted a case-control study with cases defined as pneumonia-related deaths and controls as cases with alternative causes of death. Cases were analysed by considering drugs detected at post-mortem (PM) and by drugs prescribed to the deceased at the time of their death with calculated odds ratios (ORs) adjusted to account for confounders.

RESULTS

There were 2467 PM cases and 40,128 controls; 1818 prescribed cases and 28,018 controls. Second generation antipsychotics (SGAs) were robustly associated with an increased risk of pneumonia-related death compared with those not prescribed or taking antipsychotics (PM detection adjusted OR [AOR] 1·34 [95% CI 1·15-1·55]; prescribed AOR 1·28 [95% CI 1·11-1·49]). First generation antipsychotics had no clear association with death from pneumonia (PM detection AOR 1·06 [95% CI 0·77-1·47]; prescribed AOR 0·91 [95% CI 0·71-1·17]). Amongst SGAs, olanzapine was associated with an increased risk of death due to pneumonia (PM detection AOR 1·49 [95% CI 1·22-1·82]; prescribed AOR 1·44 [95% CI 1·18-1·76]) as was quetiapine (PM detection AOR 1·34 [95% CI 1·07-1·66]; prescribed AOR 1·28 [95% CI 1·01-1·64]).

CONCLUSION

Olanzapine and quetiapine were found to increase the risk of pneumonia-related death in this NPSAD sample to a clinically important extent.

Psychotropics and COVID-19: An analysis of safety and prophylaxis

The use of psychotropics during the COVID-19 pandemic has raised two questions, in order of importance: first, what changes should be made to pharmacological treatments prescribed to mental health patients? Secondly, are there any positive side effects of these substances against SARS-CoV-2? Our aim was to analyze usage safety of psychotropics during COVID-19; therefore, herein, we have studied: (i) the risk of symptomatic complications of COVID-19 associated with the use of these drugs, notably central nervous system activity depression, QTc interval enlargement and infectious and thromboembolic complications; (ii) the risk of mistaking the iatrogenic impact of psychotropics with COVID-19 symptoms, causing diagnostic error. Moreover, we provided a summary of the different information available today for these risks, categorized by mental health disorder, for the following: schizophrenia, bipolar disorder, anxiety disorder, ADHD, sleep disorders and suicidal risk. The matter of psychoactive substance use during the pandemic is also analyzed in this paper, and guideline websites and publications for psychotropic treatments in the context of COVID-19 are referenced during the text, so that changes on those guidelines and eventual interaction between psychotropics and COVID-19 treatment medication can be reported and studied. Finally, we also provide a literature review of the latest known antiviral properties of psychotropics against SARS-CoV-2 as complementary information.

Greater than the Sum: Applying Daily-Dose Equivalents to Antipsychotic Prescription Claims to Study Real-World Effects

Traditional methods to standardize exposures in pharmacoepidemiologic studies, like defined daily-doses, may be inadequate to capture drug class effects when there are many in-class medications, formulations, and administration routes. Antipsychotic medications are one example of a drug class with these complexities. Direct dose conversion methods are pharmacologically-based but often overlooked, potentially for lack of real-world guidance and examples of their implementation. The purpose of this article is to describe a method to implement dose conversion, using an example study that quantifies antipsychotic use among a cohort of older adults with dementia. We identified 45,442 older adults (aged ≥66 years) with dementia initiating antipsychotic therapy between January 1, 2009 and December 31, 2012 in Ontario, Canada using linked administrative healthcare databases. We developed and applied a data cleaning and dose conversion algorithm to quantify antipsychotic exposure in chlorpromazine dose equivalents at initiation, month 6, and month 12 of therapy. Results were stratified by route of administration. At initiation, 14% of patients received multiple antipsychotic prescriptions simultaneously. Patients initiating regular injectable and multiple administration routes received the highest median chlorpromazine equivalent daily-doses. Data cleaning changed 3, 16, 36, and 42% of total equivalent daily-doses in patients initiating oral, regular injectable, long-acting injectable, and multiple administration routes, respectively. Dose conversion of prescription claims data was a feasible method to quantify and present antipsychotic drug exposures. Dose conversion methods can be considered for drug effects studies of antipsychotic therapies and other medication classes with complex use.

Exploring a Safety Signal of Antipsychotic-Associated Pneumonia: A Pharmacovigilance-Pharmacodynamic Study

An association between antipsychotic drugs and pneumonia has been demonstrated in several studies; however, the risk for pneumonia caused by specific antipsychotics has not been extensively studied. The underlying mechanism is still unknown, and several receptor mechanisms have been proposed. Therefore, using a combined pharmacovigilance-pharmacodynamic approach, we aimed to investigate safety signals of US Food and Drug Administration (FDA)-approved antipsychotics for reporting pneumonia and the potential receptor mechanisms involved. A disproportionality analysis was performed to detect a signal for reporting "infective-pneumonia" and "pneumonia-aspiration" and antipsychotics using reports submitted between 2004 and 2019 to the FDA adverse events spontaneous reporting system (FAERS) database. Disproportionality was estimated using the crude and the adjusted reporting odds ratio (aROR) and its 95% confidence interval (CI) in a multivariable logistic regression. Linear regressions investigated the relationship between aROR and receptor occupancy, which was estimated using in vitro receptor-binding profiles. Safety signals for reporting infective-pneumonia were identified for clozapine (LL = 95% 3.4, n = 546 [aROR: 4.8]) as well as olanzapine (LL = 95% 1.5, n = 250 [aROR: 2.1]) compared with haloperidol, while aRORs were associated with higher occupancies of muscarinic receptors (beta = .125, P-value = .016), yet other anti-muscarinic drugs were not included as potential confounders. No safety signals for reporting pneumonia-aspiration were detected for individual antipsychotics. Multiple antipsychotic use was associated with both reporting infective-pneumonia (LL 95%: 1.1, n = 369 [aROR:1.2]) and pneumonia-aspiration (LL 95%: 1.7, n = 194 [aROR: 2.0]). Considering the limitations of disproportionality analysis, further pharmacovigilance data and clinical causality assessment are needed to validate this safety signal.

Safety of Psychotropic Medications in People With COVID-19: Evidence Review and Practical Recommendations

(Reprinted with permission from the BMC Medicine (2020) 18:215).

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.

Safety of psychotropic medications in people with COVID-19: evidence review and practical recommendations

BACKGROUND

The novel coronavirus pandemic calls for a rapid adaptation of conventional medical practices to meet the evolving needs of such vulnerable patients. People with coronavirus disease (COVID-19) may frequently require treatment with psychotropic medications, but are at the same time at higher risk for safety issues because of the complex underlying medical condition and the potential interaction with medical treatments.

METHODS

In order to produce evidence-based practical recommendations on the optimal management of psychotropic medications in people with COVID-19, an international, multi-disciplinary working group was established. The methodology of the WHO Rapid Advice Guidelines in the context of a public health emergency and the principles of the AGREE statement were followed. Available evidence informing on the risk of respiratory, cardiovascular, infective, hemostatic, and consciousness alterations related to the use of psychotropic medications, and drug-drug interactions between psychotropic and medical treatments used in people with COVID-19, was reviewed and discussed by the working group.

RESULTS

All classes of psychotropic medications showed potentially relevant safety risks for people with COVID-19. A set of practical recommendations was drawn in order to inform frontline clinicians on the assessment of the anticipated risk of psychotropic-related unfavorable events, and the possible actions to take in order to effectively manage this risk, such as when it is appropriate to avoid, withdraw, switch, or adjust the dose of the medication.

CONCLUSIONS

The present evidence-based recommendations will improve the quality of psychiatric care in people with COVID-19, allowing an appropriate management of the medical condition without worsening the psychiatric condition and vice versa.

[Informations on psychotropics and their adaptations for patients suffering from mental disorders in France during the SARS-CoV-2 epidemic]

The 2019-20 coronavirus pandemic (SARS-CoV-2; severe acute respiratory syndrome coronavirus 2) has dramatic consequences on populations in terms of morbidity and mortality and in social terms, the general confinement of almost half of the world's population being a situation unprecedented in history, which is difficult today to measure the impact at the individual and collective levels. More specifically, it affects people with various risk factors, which are more frequent in patients suffering from psychiatric disorders. Psychiatrists need to know: (i) how to identify, the risks associated with the prescription of psychotropic drugs and which can prove to be counterproductive in their association with COVID-19 (coronavirus disease 2019), (ii) how to assess in terms of benefit/risk ratio, the implication of any hasty and brutal modification on psychotropic drugs that can induce confusion for a differential diagnosis with the evolution of COVID-19. We carried out a review of the literature aimed at assessing the specific benefit/risk ratio of psychotropic treatments in patients suffering from COVID-19. Clinically, symptoms suggestive of COVID-19 (fever, cough, dyspnea, digestive signs) can be caused by various psychotropic drugs and require vigilance to avoid false negatives and false positives. In infected patients, psychotropic drugs should be used with caution, especially in the elderly, considering the pulmonary risk. Lithium and Clozapine, which are the reference drugs in bipolar disorder and resistant schizophrenia, warrant specific attention. For these two treatments the possibility of a reduction in the dosage - in case of minimal infectious signs and in a situation, which does not allow rapid control - should ideally be considered taking into account the clinical response (even biological; plasma concentrations) observed in the face of previous dose reductions. Tobacco is well identified for its effects as an inducer of CYP1A2 enzyme. In a COVID+ patient, the consequences of an abrupt cessation of smoking, particularly related with the appearance of respiratory symptoms (cough, dyspnea), must therefore be anticipated for patients receiving psychotropics metabolized by CYP1A2. Plasma concentrations of these drugs are expected to decrease and can be related to an increase risk of relapse. The symptomatic treatments used in COVID-19 have frequent interactions with the most used psychotropics. If there is no curative treatment for infection to SARS-CoV-2, the interactions of the various molecules currently tested with several classes of psychotropic drugs (antidepressants, antipsychotics) are important to consider because of the risk of changes in cardiac conduction. Specific knowledge on COVID-19 remains poor today, but we must recommend rigor in this context in the use of psychotropic drugs, to avoid adding, in patients suffering from psychiatric disorders, potentially vulnerable in the epidemic context, an iatrogenic risk or loss of efficiency.

Prediction of Potential Drug-Disease Associations through Deep Integration of Diversity and Projections of Various Drug Features

Identifying new indications for existing drugs may reduce costs and expedites drug development. Drug-related disease predictions typically combined heterogeneous drug-related and disease-related data to derive the associations between drugs and diseases, while recently developed approaches integrate multiple kinds of drug features, but fail to take the diversity implied by these features into account. We developed a method based on non-negative matrix factorization, DivePred, for predicting potential drug–disease associations. DivePred integrated disease similarity, drug–disease associations, and various drug features derived from drug chemical substructures, drug target protein domains, drug target annotations, and drug-related diseases. Diverse drug features reflect the characteristics of drugs from different perspectives, and utilizing the diversity of multiple kinds of features is critical for association prediction. The various drug features had higher dimensions and sparse characteristics, whereas DivePred projected high-dimensional drug features into the low-dimensional feature space to generate dense feature representations of drugs. Furthermore, DivePred’s optimization term enhanced diversity and reduced redundancy of multiple kinds of drug features. The neighbor information was exploited to infer the likelihood of drug–disease associations. Experiments indicated that DivePred was superior to several state-of-the-art methods for prediction drug-disease association. During the validation process, DivePred identified more drug-disease associations in the top part of prediction result than other methods, benefitting further biological validation. Case studies of acetaminophen, ciprofloxacin, doxorubicin, hydrocortisone, and ampicillin demonstrated that DivePred has the ability to discover potential candidate disease indications for drugs.

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.

All-cause mortality and antipsychotic use among elderly persons with high baseline cardiovascular and cerebrovascular risk: a multi-center retrospective cohort study in Italy

BACKGROUND

Little is known about the comparative risk of death with atypical or conventional antipsychotics (APs) among persons with cardiovascular or cerebrovascular disease (CCD).

RESEARCH DESIGN AND METHODS

A cohort study was conducted using five Italian claims databases. New atypical AP users with CCD aged ≥65 (reference) were matched to new conventional AP users. Mortality per 100 person-years (PYs) and hazard ratios (HR), estimated using Cox models, were reported. Incidence and risk of death were estimated for persons having drug-drug interactions. Outcome occurrence was evaluated 180 days after AP initiation.

RESULTS

Overall 24,711 and 27,051 elderly new conventional and atypical AP users were identified. The mortality rate was 51.3 and 38.5 deaths per 100 PYs for conventional and atypical AP users. Mortality risk was 1.33 (95%CI: 1.27-1.39) for conventional APs. There was no increased mortality risk with single drug-drug interactions (DDIs) vs. no DDI. AP users with ≥1 DDI had a 29% higher mortality risk compared to no DDI in the first 90 days of treatment (HR: 1.29 (95% CI: 1.00-1.67)).

CONCLUSIONS

Conventional APs had a higher risk of death than atypical APs among elderly persons with CCD. Having ≥1 DDI was associated with an increased risk of death.

Antipsychotic drug use and pneumonia: Systematic review and meta-analysis

OBJECTIVES

The purpose of this study was to investigate the association of antipsychotic exposure to the incidence and mortality of pneumonia.

METHODS

The design of this study involved meta-analysis of observational studies identified from electronic databases.

RESULTS

In total, 19 studies were included in the systematic review and 14 in the meta-analysis. Risk of pneumonia was increased by first-generation antipsychotics (risk ratio 1.69, 95% confidence interval 1.34-2.15; five studies), second-generation antipsychotics (risk ratio 1.93, 95% confidence interval 1.55-2.41; six studies) and all antipsychotics (risk ratio 1.83, 95% confidence interval 1.60-2.10; seven studies) compared with no antipsychotic use. Pneumonia risk did not differ in seven studies comparing first-generation antipsychotics with second-generation antipsychotics (risk ratio 1.07, 95% confidence interval 0.85-1.35). Case fatality rate was not different in pneumonia cases associated with antipsychotic exposure versus cases without exposure (risk ratio 1.50; 95% confidence interval 0.76-2.96; two studies). All antipsychotics with data from ⩾2 studies allowing meta-analysis, were associated with a significantly increased pneumonia risk (i.e. haloperidol, olanzapine, clozapine, risperidone, quetiapine, zotepine).

CONCLUSION

Exposure to both first-generation antipsychotics and second-generation antipsychotics is associated with an increased pneumonia risk. Clinicians need to be vigilant for the occurrence of pneumonia in patients commencing antipsychotics, especially those with other risk factors for pneumonia including older age, chronic respiratory disease, cerebrovascular disease, dysphagia and smoking.

Drugs that increase the risk of community-acquired pneumonia: a narrative review

INTRODUCTION

Community-acquired pneumonia (CAP), a major cause of morbidity and mortality, is the leading infectious cause of death in the developed world. Population-based studies and systematic reviews have identified a large number of risk factors for the development of pneumonia in adults. In addition to age, lifestyle habits, and comorbidities, some forms of pharmacotherapy may also increase the risk for CAP.

AREAS COVERED

MEDLINE, CENTRAL, and Web of Science were used in 2017 to search for case-control, cohort studies, as well as randomized controlled trials and meta-analysis that involved outpatient proton pump inhibitors (PPIs), inhaled corticosteroids (ICSs), antipsychotics, oral antidiabetics, and CAP diagnosis in patients aged >18 years.

EXPERT OPINION

Our review confirmed that the use of ICSs, PPIs or antipsychotic drugs was independently associated with an increased risk for CAP. We also identified a positive association between specific oral antidiabetics and the development of pneumonia.

Potentially fatal outcomes associated with clozapine

Clozapine has been shown to be the most efficacious therapy for treatment resistant schizophrenia, estimated at one third of all schizophrenia cases. There is significant morbidity and mortality associated with clozapine including risk of agranulocytosis, aspiration pneumonia, bowel ischemia, myocarditis, seizures, and weight gain. Here we present a case of a 62-year-old man with chronic paranoid schizophrenia refractory to numerous antipsychotics who was started on clozapine therapy during an acute inpatient psychiatric admission. Within three weeks of starting clozapine, the patient developed flu-like symptoms, pleuritic chest pain, and was sent to a medical hospital for evaluation. After transfer, the patient had a rapidly deteriorating course with newly developed congestive heart failure, acute respiratory failure requiring intubation, and cardiovascular collapse requiring vasopressors. The patient expired within two days of transfer and four days after initial symptoms developed. The underlying etiology in this case is likely clozapine induced myocarditis leading to rapid cardiovascular collapse and death. Mortality with clozapine induced myocarditis has been estimated up to 24%. Given that 90% of clozapine cardiotoxic sequelae are seen in the first month post-initiation, more rigorous post-initiation surveillance is recommended for the first four weeks of clozapine with weekly cardiac enzymes (troponins, creatinine kinase-MB), EKG, and acute inflammatory markers (C-reactive protein, and erythrocyte sedimentation rate).

Sudden death in schizophrenia

PURPOSE OF REVIEW

To examine the recent literature regarding sudden death in patients with schizophrenia and synthesize salient conclusions based on this evidence.

RECENT FINDINGS

Sudden cardiac death (SCD) is the largest subset of sudden unexpected death (SUD), with up to 40% of SUD from cardiovascular causes. SCD has been associated with exposure to both first and second-generation antipsychotics. Clozapine [odds ratio (OR) 3.67, 95% confidence interval (CI) 1.94-6.94] confers the highest risk of SCD followed by risperidone (OR 3.04, 95% CI 2.39-3.86) then olanzapine (OR 2.04, 95% CI 1.52-2.74). SCD not associated with antipsychotic use has been correlated to several modifiable and nonmodifiable risk factors - obesity, smoking, dyslipidemia, diabetes, hypertension, age, sex, and history of cardiovascular disease. Other subsets of SUD include hematological and pulmonary causes, including agranulocytosis leading to sepsis, deep vein thrombosis leading to pulmonary embolisms, and aspiration pneumonia leading to sepsis.

SUMMARY

There is a huge paucity in genetic and pharmacogenetic data focused on SUD in schizophrenia. Future studies should emphasize the genetic aspects as well as clarify the underlying molecular mechanisms of these pathways. Additionally, early detection of those patients at high risk for SUD and discovery of preventive measures should also be emphasized.