Involvement of virus infections and antiviral agents in schizophrenia

BACKGROUND

Schizophrenia is a chronic and complex mental disorder resulting from interactions between cumulative and synergistic genetic and environmental factors. Viral infection during the prenatal stage constitutes one of the most relevant risk factors for the development of schizophrenia later in adulthood.

METHODS

A narrative review was conducted to explore the link between viral infections and schizophrenia, as well as the neuropsychiatric effects of antiviral drugs, particularly in the context of this specific mental condition. Literature searches were performed using the PubMed, Scopus, and Web of Science databases.

RESULTS

Several viral infections, such as herpesviruses, influenza virus, Borna disease virus, and coronaviruses, can directly or indirectly disrupt normal fetal brain development by modifying gene expression in the maternal immune system, thereby contributing to the pathophysiological symptoms of schizophrenia. In addition, neuropsychiatric effects caused by antiviral drugs are frequent and represent significant adverse outcomes for viral treatment.

CONCLUSIONS

Epidemiological evidence suggests a potential relationship between viruses and schizophrenia. Increases in inflammatory cytokine levels and changes in the expression of key genes observed in several viral infections may constitute potential links between these viral infections and schizophrenia. Furthermore, antivirals may affect the central nervous system, although for most drugs, their mechanisms of action are still unclear, and a strong relationship between antivirals and schizophrenia has not yet been established.

Risk of neuropsychiatric adverse events associated with montelukast use in children and adolescents: a population-based case-crossover study

PURPOSE

Montelukast is used extensively in children and adolescents for allergic rhinitis and asthma. However, concerns have been raised regarding the increased risk of neuropsychiatric adverse events (NPAEs) associated with montelukast use. Therefore, our case-crossover study was conducted to observe whether there is an increased risk of NPAEs associated with montelukast use in children and adolescents.

MATERIALS AND METHODS

A population-based case-crossover study using the customised Health Insurance Review and Assessment (HIRA) dataset was conducted. Paediatric patients aged between 0 and 19 years diagnosed with allergic rhinitis and/or asthma with a history of at least one montelukast prescription between 1 January 2018 and 31 December 2021 were included. Exposure to montelukast was assessed during 3-, 7-, 14-, 28- and 56-day hazard periods prior to each patient's NPAE. Stratified analyses according to age group, gender and season for the risk of NPAEs associated with montelukast use in the previous 7 days and 14 days were performed, respectively. Conditional logistic regression analysis was used to calculate adjusted ORs (aORs) with their corresponding 95% CIs, adjusting for concomitant medications.

RESULTS

A total of 161 386 paediatric patients was identified. An increased risk of NPAEs associated with montelukast was found in all time window periods, including 3-day (aOR 1.28, 95% CI 1.24 to 1.32), 7-day (aOR 1.29, 95% CI 1.26 to 1.33), 14-day (aOR 1.34, 95% CI 1.31 to 1.37), 28-day (aOR 1.38, 95% CI 1.36 to 1.41) and 56-day (aOR 1.21, 95% CI 1.19 to 1.22) preceding hazard periods compared with use in the four control periods.

CONCLUSION

Children and adolescents with allergic rhinitis and/or asthma should be prescribed montelukast with caution considering clinical benefits.

Considerations when treating influenza infections with oseltamivir

INTRODUCTION

Since the coronavirus disease 2019-mandated social distancing policy has been lifted worldwide, the circulation of influenza is expected to resume. Currently, oseltamivir is approved as the first-line agent for influenza prevention and treatment.

AREAS COVERED

This paper reviews the updated evidence in the pharmacology, resistance mechanisms, clinical pharmacy management, and real-world data on oseltamivir for influenza.

EXPERT OPINION

Oseltamivir is an oral prodrug of oseltamivir carboxylate, an influenza A and B neuraminidase inhibitor. Recently, the therapeutic efficacy of oseltamivir has been demonstrated in several trials. Oseltamivir is generally well-tolerated but may lead to neuropsychiatric events and bleeding. Oseltamivir-resistant influenza virus has been associated with the H275Y mutation in the influenza A(H1N1)pdm09 virus, while most strains are still sensitive to oseltamivir. Dose adjustment for oseltamivir should be based on creatinine clearance and body weight in pediatric patients with renal failure. According to real-world data from Nanfang Hospital, the annual number of patients prescribed oseltamivir declined from 35,711 in 2019 to 8,971 in 2020, with marked increases in 2022 (20,213) and 2023 (18,071). Among the 206 inpatients, children aged < 6 years who were treated with oseltamivir had the shortest duration to defervescence.

Risk of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Associated With Antibiotic Use: A Case-Crossover Study

BACKGROUND

Evidence is lacking on the association between antibiotic use and risk of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in Asians.

OBJECTIVE

We assessed the risk of SJS/TEN associated with different antibiotic classes in Japanese.

METHODS

We conducted a case-crossover study using a claims database. Firth conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of SJS/TEN associated with antibiotic use in a 56-day hazard period versus 3 control periods. We created 18 cohorts for each antibiotic class and calculated 56-day cumulative incidence per 100,000 new users. The association between antibiotic class and SJS/TEN was also evaluated in each case using the ALgorithm of Drug causality for Epidermal Necrolysis (ALDEN).

RESULTS

Our case-crossover study included 170 SJS/TEN cases. Increased ORs were observed for lincomycins (OR, 33.00 [95% CI, 3.74-4332.05]), trimethoprim-sulfamethoxazole (21.20 [6.73-105.98]), penicillins (14.39 [6.95-34.21]), glycopeptides (14.37 [3.17-136.10]), cephalosporins (7.06 [4.25-12.21]), aminoglycosides (6.55 [1.97-26.84]), quinolones (5.98 [3.34-11.20]), fosfomycin (5.40 [1.20-30.97]), carbapenems (5.09 [1.85-15.64]), tetracyclines (4.95 [1.78-15.27]), and macrolides (3.78 [2.13-6.83]). Cumulative incidence of SJS/TEN was 67.4 for trimethoprim-sulfamethoxazole, 86.2 for glycopeptides, and below 10.0 for the others. Despite the high incidence, only 2 cases had a probable causal relationship with glycopeptides.

CONCLUSION

Some antibiotic classes, including lincomycins, glycopeptides, aminoglycosides, fosfomycin, and carbapenems, were newly suggested to be associated with risk of SJS/TEN; considered together with the high incidence for trimethoprim-sulfamethoxazole and glycopeptides, these findings warrant caution in clinical practice.

Influenza in Children and Adolescents: Epidemiology, Management, and Prevention

EDUCATION GAP

Influenza is among the most common infectious causes of pediatric emergency department visits and hospitalizations. Clinicians should use evidence-based guidelines to learn how to identify, manage, prevent, and treat influenza cases. Disease caused by influenza virus can be mitigated with appropriate treatment and prevention efforts.

OBJECTIVES After completing this article, readers should be able to:

1. Describe the virology and epidemiology of influenza.

2. List the clinical features and complications of influenza infections.

3. List the benefits and limitations of testing modalities for the diagnosis of influenza.

4. Appropriately apply American Academy of Pediatrics, Infectious Diseases Society of America, and Centers for Disease Control and Prevention (CDC) treatment guidelines for influenza or suspected influenza.

5. Describe the importance of influenza vaccination.

Evaluating the use of methods to mitigate bias from non-transient medications in the case-crossover design: A systematic review

PURPOSE

The case-crossover design is a self-controlled study design used to compare exposure immediately preceding an event occurrence with exposure in earlier control periods. The design is most suitable for transient exposures in order to avoid biases that can be problematic when using the case-crossover design for non-transient (i.e., chronic) exposures. Our goal was to conduct a systematic review of case-crossover studies and its variants (case-time-control and case-case-time-control) in order to compare design and analysis choices by medication type.

METHODS

We conducted a systematic search to identify recent case-crossover, case-time-control, and case-case-time-control studies focused on medication exposures. Articles indexed in MEDLINE and EMBASE using these study designs that were published between January 2015 and December 2021 in the English language were identified. Reviews, methodological studies, commentaries, articles without medications as the exposure of interest, and articles with no available full text were excluded. Study characteristics including study design, outcome, risk window, control window, reporting of discordant pairs, and inclusion of sensitivity analyses were summarized overall and by medication type. We further evaluated the implementation of recommended methods to account for biases introduced by non-transient exposures among articles that used the case-crossover design on a non-transient exposure.

RESULTS

Of the 2036 articles initially identified, 114 articles were included. The case-crossover was the most common study design (88%), followed by the case-time-control (17%), and case-case-time-control (3%). Fifty-three percent of the articles included only transient medications, 35% included only non-transient medications, and 12% included both. Across years, the proportion of case-crossover articles evaluating a non-transient medication ranged from 30% in 2018 to 69% in 2017. We found that 41% of the articles that evaluated a non-transient medication did not apply any of the recommended methods to account for biases and more than half of which were conducted by authors with no previous publication history of case-crossover studies.

CONCLUSION

Using the case-crossover design to evaluate a non-transient medication remains common in pharmacoepidemiology. Researchers should apply appropriate design and analysis choices when opting to use a case-crossover design with non-transient medication exposures.

Repurposing of antiviral drugs for COVID-19 and impact of repurposed drugs on the nervous system

The recent pandemic, Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has devastated humanity and is continuing to threaten us. Due to the high transmissibility of this pathogen, researchers are still trying to cope with the treatment and prevention of this disease. Few of them were successful in finding cure for COVID-19 by including repurposed drugs in the treatment. In such pandemic situations, when it is nearly impossible to design and implement a new drug target, previously designed antiviral drugs could help against novel viruses, referred to as drug repurposing/redirecting/repositioning or re-profiling. This review describes the current landscape of the repurposing of antiviral drugs for COVID-19 and the impact of these drugs on our nervous system. In some cases, specific antiviral therapy has been notably associated with neurological toxicity, characterized by peripheral neuropathy, neurocognitive and neuropsychiatric effects within the central nervous system (CNS).

Influenza-associated Neurologic Complications in Hospitalized Pediatric Patients: A Multicenter Retrospective Study in Republic of Korea

BACKGROUND

The rates of influenza-associated neurologic complications are variable among studies, and a difference has been observed between the Western and Asian countries. The study aims to evaluate the frequency and characteristics of influenza-associated neurologic complications.

METHODS

We performed a retrospective review of hospitalized cases of influenza infection from October 2010 to April 2017 from 3 referral hospitals.

RESULTS

A total of 1988 influenza cases were identified. Influenza-associated neurologic complications were 161 cases (8.1%); influenza virus A was detected in 113 (70.2%) cases, B in 47 (29.2%) cases and both A and B in 1 case (0.6%). Twenty-four patients (15%) had underlying neurologic diseases. The most common diagnosis was a simple febrile convulsion (44%), followed by complex febrile convulsion (29%), fever-provoked seizure under pre-existing neurologic disease or afebrile seizure (14%), encephalopathy/encephalitis (8%) and meningitis (5%). Most of the patients fully recovered (96%). Three patients (1.9%) died of myocarditis (n = 1), encephalopathy (n = 1), and simultaneous encephalitis and myocarditis (n = 1). Pre-existing neurologic disease, age groups of 6 months to 6 years and 6-12 years were a risk factor of influenza-associated neurologic complications with an adjusted odds ratio of 5.41 (95% confidence interval [CI] 3.23-9.06, P < 0.001), 12.99 (95% CI 1.77-95.19, P = 0.01) and 8.54 (95% CI 1.14-64.79, P = 0.04), respectively. There was no association between neuropsychiatric adverse events and oseltamivir prescription (P = 0.17).

CONCLUSIONS

Influenza-associated neurologic complications are not uncommon, and most patients fully recovered. The frequency of influenza-associated neurologic complications in Korean children was not significantly different from that of children in Western countries.

Oseltamivir-Induced Mania in a Patient With Influenza A

ABSTRACT

Oseltamivir is an antiviral drug often preferred in treating viral infections. Its use has increased owing to annual influenza outbreaks and the COVID-19 pandemic. Although its adverse effects are often seen in the gastrointestinal system, it has other adverse effects that can prevent its use, for example, neuropsychiatric events. In this case report, we present a manic episode case caused by the use of oseltamivir.

Oseltamivir and the Risk of Neuropsychiatric Events: A National, Population-based Study

BACKGROUND

Reports of serious neuropsychiatric events (NPEs), specifically suicide/suicide attempts, following the use of oseltamivir have led to public concerns. Our aim in this study was to determine whether an association exists between oseltamivir use and NPEs.

METHOD

This study was a population-based, retrospective, cohort study on a random sample of 50% of individuals in the Korean National Health Insurance Service (KNIS) database aged ≥8 years who were diagnosed with influenza between 2009 and 2017. The primary exposure was oseltamivir prescription at the time of influenza diagnosis, whereas the primary outcome was a diagnosis of an NPE within 30 days after the influenza diagnosis. Information on oseltamivir prescription, diagnoses of NPEs, demographic characteristics, comorbidities, drugs prescribed within the year before influenza diagnosis, and healthcare utilization were extracted from the KNIS database.

RESULTS

Of 3 352 015 individuals included in the analysis, 1 266 780 (37.8%) were prescribed oseltamivir. The incidence of NPEs was 0.86% and 1.16% in patients who were and were not prescribed oseltamivir, respectively (hazard ratio [HR], 0.74; 95% confidence interval [CI], .73 to .75; P < .001). Oseltamivir use was not associated with a difference in the overall risk of NPEs in the adjusted model (HR, 0.98; 95% CI, .96 to 1.01; P = .16), but the incidence of moderate-to-severe NPEs was significantly lower in those prescribed oseltamivir (HR, 0.92; 95% CI, .88-.96; P < .001).

CONCLUSION

Treating influenza with oseltamivir does not increase the risk of NPEs. Thus, public concern regarding its use is unwarranted.

Dexamethasone plus oseltamivir versus dexamethasone in treatment-naive primary immune thrombocytopenia: a multicentre, randomised, open-label, phase 2 trial

BACKGROUND

Primary immune thrombocytopenia is an autoimmune bleeding disorder. Preclinical reports suggest that the sialidase inhibitor oseltamivir induces a platelet response in the treatment of immune thrombocytopenia. This study investigated the activity and safety of dexamethasone plus oseltamivir versus dexamethasone alone as initial treatment in adult patients with primary immune thrombocytopenia.

METHODS

This multicentre, randomised, open-label, parallel group, phase 2 trial was done in five tertiary medical hospitals in China. Eligible patients were aged 18 years or older with newly diagnosed, treatment-naive primary immune thrombocytopenia. Participants were randomly assigned (1:1), using block randomisation, to receive either dexamethasone (orally at 40 mg per day for 4 days) plus oseltamivir (orally at 75 mg twice a day for 10 days) or dexamethasone monotherapy (orally at 40 mg a day for 4 days). Patients who did not respond to treatment (platelet counts remained <30 × 10⁹ cells per L or showed bleeding symptoms by day 10) were given an additional cycle of dexamethasone for 4 days in each group. Patients in the dexamethasone plus oseltamivir group who relapsed (platelet counts reduced again to <30 × 10⁹ cells per L) after an initial response were allowed a supplemental course of oseltamivir (75 mg twice a day for 10 days). The coprimary endpoints were 14-day initial overall response and 6-month overall response. Complete response was defined as a platelet count at or above 100 × 10⁹ cells per L and an absence of bleeding. Partial response was defined as a platelet count at or above 30 × 10⁹ cells per L but less than 100 × 10⁹ cells per L and at least a doubling of the baseline platelet count and an absence of bleeding. A response lasting for at least 6 months without any additional primary immune thrombocytopenia-specific intervention was defined as sustained response. All patients who were randomly assigned and received the allocated intervention were included in the modified intention-to-treat population analysis. This study has been completed and is registered with ClinicalTrials.gov, number NCT01965626.

FINDINGS

From Feb 1, 2016, to May 1, 2019, 120 patients were screened for eligibility, of whom 24 were ineligible and excluded, 96 were enrolled and randomly assigned to receive dexamethasone plus oseltamivir (n=47) or dexamethasone (n=49), and 90 were included in the modified intention-to-treat analysis. Six patients did not receive the allocated intervention. Patients in the dexamethasone plus oseltamivir group had a significantly higher initial response rate (37 [86%] of 43 patients) than did those in the dexamethasone group (31 [66%] of 47 patients; odds ratio [OR] 3·18; 95 CI% 1·13-9·23; p=0·030) at day 14. The 6-month sustained response rate in the dexamethasone plus oseltamivir group was also significantly higher than that in the dexamethasone group (23 [53%] vs 14 [30%]; OR 2·17; 95 CI% 1·16-6·13; p=0·032). During the median follow-up of 8 months (IQR 5-14), two of 90 patients discontinued treatment due to serious adverse events (grade 3); one (2%) patient with general oedema in the dexamethasone plus oseltamivir group and one (2%) patient with fever in the dexamethasone group. The most frequently observed adverse events of any grade were fatigue (five [12%] of 43 in the dexamethasone plus oseltamivir group vs eight [17%] of 47 in the dexamethasone group), gastrointestinal reactions (eight [19%] vs three [6%]), insomnia (seven [16%] vs four [9%]), and anxiety (five [12%] vs three [6%]). There were no grade 4 or 5 adverse events and no treatment-related deaths.

INTERPRETATION

Dexamethasone plus oseltamivir offers a readily available combination therapy in the management of newly diagnosed primary immune thrombocytopenia. The preliminary activity of this combination warrants further investigation. Multiple cycles of oseltamivir, as a modification of current first-line treatment, might be more effective in maintaining the platelet response.

FUNDING

National Natural Science Foundation of China.

Association between oseltamivir use and neuropsychiatric adverse events in influenza patients: a nationwide population-based cohort study

Background: A potential risk of neuropsychiatric adverse events (NPAEs) of oseltamivir has remained controversial by retrospective cohort studies. This nationwide population-based cohort study aimed to assess the risk of NPAEs in influenza patients undergoing oseltamivir treatment (users) compared with a propensity score-matched cohort of patients not receiving oseltamivir (non-users). Research design and methods: Using the Korean National Health Service-Sample Cohort Database, patients diagnosed with incident influenza during 2003-2013 were divided into two cohorts: oseltamivir users and non-users. We calculated adjusted hazard ratios (aHRs) for the 5-day treatment course with oseltamivir using Cox regression analysis. Results: The incidence rate of NPAEs during 5-day oseltamivir treatment was 0.0029 and 0.0023 in oseltamivir users and non-users, respectively. The risk of NPAEs was different according to age, with an increased risk in patients aged 10-19 years (aHR 2.69, 95% CI 1.05-6.93) and a decreased risk in patients aged 0-9 years (aHR 0.46, 95% CI 0.24-0.88). The non-significant positive associations were observed in patients aged 20-64 years and those aged greater than 65 years. Conclusions: Although the reason for the inverse association in children aged 0-9 years is unknown, oseltamivir could increase the risk of NPAEs for children or adolescents aged greater than 10 years.

Neuropsychiatric Effects of Antiviral Drugs

The adverse events of antiviral drugs are dose-dependent and often reversible. The nervous system is often affected and to date, many studies have been published regarding the central nervous system toxicity of antiviral agents. They may cause significant neuropsychiatric complications, which range from mild symptoms such as irritability and difficulty sleeping to severe complications such as depression, psychosis, and painful peripheral neuropathy, side effects which may necessitate discontinuation of treatment. The pathogenetic mechanisms may involve molecular targets common to other centrally active drugs, including human monoamine oxidase‐A (MAO‐A), serotonin receptors, gamma-aminobutyric acid (GABA) GABA-A receptors, 5-HT2A and 5-HT2C receptors and others. Notable examples include oseltamivir which may act as MAO inhibitor and efavirenz, which has an affinity for serotonin 5-HT2 and GABA-A receptors, the serotonin transporter, the MAO enzyme, and the vesicular monoamine transporter, with subjective effects which may be similar to those of the psychedelic hallucinogen lysergic acid diethylamide (LSD). Other antiviral drugs with prominent nervous system effects include nucleoside reverse transcriptase inhibitors, which are associated with the development of peripheral neuropathy after prolonged use (an effect strongly associated with older drugs which have since fallen into disfavor such as stavudine) and interferons, which may cause depression. Clinicians should be familiar with such adverse effects in order to recognise them promptly once they occur and manage them appropriately.

Oseltamivir-induced behavioral changes in a female Lebanese adolescent: a case report of a usual drug with unusual side effect

Neuropsychiatric symptoms, including abnormal behavior, after oseltamivir use among influenza patients have been of concern. In recent years, many case reports of neuropsychiatric events during or after oseltamivir treatment were reported; however, literature review revealed no such cases in Lebanon. Oseltamivir is the most widely prescribed medication against influenza and is generally well tolerated, causing random gastrointestinal disturbances, including nausea, vomiting, diarrhea and abdominal pain. However, in rare instances, it has been reported to stimulate behavioral activities in adolescents. We report herein a case of an oseltamivir-related neuropsychiatric event in a female adolescent in Lebanon, which resolved 2 days after stopping the drug.

Association of moderately abnormal behavior and administered neuraminidase inhibitors

Our earlier study investigated the incidence of severe abnormal behavior associated with neuraminidase inhibitors (NIs), but some studies have specifically examined the association of oseltamivir use and moderately abnormal behavior. Therefore, this study was undertaken to assess associations between moderately abnormal behavior and administered drugs. All cases of patients with influenza who exhibited moderately abnormal behavior were reported to us by physicians of all sentinel clinics and hospitals for influenza throughout Japan. Open Data of the National Database of Electronic Medical Claims include the numbers of patients diagnosed as having influenza who were prescribed NI. Incidence by NI was tested using Fisher's exact test. We received 518 moderately abnormal cases in 5-9-year-olds and 207 moderately abnormal behavior cases in 10-19-year-olds. The incidence among NI ranged from 193 per one million influenza patients in laninamivir among 10-19-year-olds to 1021 for peramivir among 5-9-year-olds. Estimation results revealed the order of risk among NIs as peramivir, oseltamivir, zanamivir and laninamivir in moderate abnormal behavior. Because of data limitations, risk among patients with and without NI cannot be compared.