Oseltamivir Dosing in Critically Ill Patients With Severe Influenza

The effect of oseltamivir use in critically ill patients with COVID-19: A multicenter propensity score-matched study

Background

Oseltamivir has been used as adjunctive therapy in the management of patients with COVID-19. However, the evidence about using oseltamivir in critically ill patients with severe COVID-19 remains scarce. This study aims to evaluate the effectiveness and safety of oseltamivir in critically ill patients with COVID-19.

Methods

This multicenter, retrospective cohort study includes critically ill adult patients with COVID-19 admitted to the intensive care unit (ICU). Patients were categorized into two groups based on oseltamivir use within 48 hours of ICU admission (Oseltamivir vs. Control). The primary endpoint was viral load clearance.

Results

A total of 226 patients were matched into two groups based on their propensity score. The time to COVID-19 viral load clearance was shorter in patients who received oseltamivir (11 vs. 16 days, p = 0.042; beta coefficient: -0.84, 95%CI: (-1.33, 0.34), p = 0.0009). Mechanical ventilation (MV) duration was also shorter in patients who received oseltamivir (6.5 vs. 8.5 days, p = 0.02; beta coefficient: -0.27, 95% CI: [-0.55,0.02], P = 0.06). In addition, patients who received oseltamivir had lower odds of hospital/ventilator-acquired pneumonia (OR:0.49, 95% CI:(0.283,0.861), p = 0.01). On the other hand, there were no significant differences between the groups in the 30-day and in-hospital mortality.

Conclusion

Oseltamivir was associated with faster viral clearance and shorter MV duration without safety concerns in critically ill COVID-19 patients.

Characterization of the In Vitro and In Vivo Efficacy of Baloxavir Marboxil against H5 Highly Pathogenic Avian Influenza Virus Infection

Human infections caused by the H5 highly pathogenic avian influenza virus (HPAIV) sporadically threaten public health. The susceptibility of HPAIVs to baloxavir acid (BXA), a new class of inhibitors for the influenza virus cap-dependent endonuclease, has been confirmed in vitro, but it has not yet been fully characterized. Here, the efficacy of BXA against HPAIVs, including recent H5N8 variants, was assessed in vitro. The antiviral efficacy of baloxavir marboxil (BXM) in H5N1 virus-infected mice was also investigated. BXA exhibited similar in vitro activities against H5N1, H5N6, and H5N8 variants tested in comparison with seasonal and other zoonotic strains. Compared with oseltamivir phosphate (OSP), BXM monotherapy in mice infected with the H5N1 HPAIV clinical isolate, the A/Hong Kong/483/1997 strain, also caused a significant reduction in viral titers in the lungs, brains, and kidneys, thereby preventing acute lung inflammation and reducing mortality. Furthermore, compared with BXM or OSP monotherapy, combination treatments with BXM and OSP using a 48-h delayed treatment model showed a more potent effect on viral replication in the organs, accompanied by improved survival. In conclusion, BXM has a potent antiviral efficacy against H5 HPAIV infections.

Outcomes of early oseltamivir treatment for hospitalized adult patients with community-acquired influenza pneumonia

Early initiation of oseltamivir within 48 h to 5 days from illness onset has been associated with improved survival among patients with community-acquired influenza pneumonia. Delay of hospitalization limits early treatment and the survival of patients. To date, the effects of early oseltamivir initiation within 24 hours from admission on patient mortality has remained unknown. This retrospective study reviewed and analyzed the clinical and non-clinical outcomes of 143 patients, with community-acquired influenza pneumonia, who received oseltamivir within 24 h (group A) and after 24 h (group B) from admission. Among the patients, 82 (57.3%) received oseltamivir within 24 h while 61 (42.7%) received oseltamivir after 24 h. The median time from symptom onset to admission for group A and group B was not statistically significant (P < 0.001). The 14-day mortality rate was 9% and 23% for group A and B, respectively (P = 0.03), while the 30-day mortality were 15% and 30% for group A and B, respectively (P = 0.05). Administration of oseltamivir within 24 h significantly affected 30-day mortality rates (adjust OR: 0.14, 95% CI: 0.47–0.04, P < 0.01), particularly among patients with respiratory failure at admission (adjust OR: 0.08, 95% CI: 0+.30–0.06, P < 0.01). Survival analysis of patient with influenza pneumonia and respiratory failure at admission demonstrated significant difference between those who received oseltamivir within and after 24 h (P = 0.002). The results indicated that early oseltamivir initiation within 24 h improved the survival outcome mainly among those with respiratory failure at admission.

Critical Care of Patients With Cardiopulmonary Complications of Sarcoidosis

Sarcoidosis is a systemic inflammatory disease defined by the presence of aberrant granulomas affecting various organs. Due to its multisystem involvement, care of patients with established sarcoidosis becomes challenging, especially in the intensive care setting. While the lungs are typically involved, extrapulmonary manifestations also occur either concurrently or exclusively within a significant proportion of patients, complicating diagnostic and management decisions. The scope of this review is to focus on what considerations are necessary in the evaluation and management of patients with known sarcoidosis and their associated complications within a cardiopulmonary and critical care perspective.

How To Prescribe And Troubleshoot Continuous Renal Replacement Therapy: A Case-Based Review

Continuous RRT (CRRT) is the preferred dialysis modality for solute management, acid-base stability, and volume control in patients who are critically ill with AKI in the intensive care unit (ICU). CRRT offers multiple advantages over conventional hemodialysis in the critically ill population, such as greater hemodynamic stability, better fluid management, greater solute control, lower bleeding risk, and a more continuous (physiologic) approach of kidney support. Despite its frequent use, several aspects of CRRT delivery are still not fully standardized, or do not have solid evidence-based foundations. In this study, we provide a case-based review and recommendations of common scenarios and interventions encountered during the provision of CRRT to patients who are critically ill. Specific focus is on initial prescription, CRRT dosing, and adjustments related to severe hyponatremia management, concomitant extracorporeal membrane oxygenation support, dialysis catheter placement, use of regional citrate anticoagulation, and antibiotic dosing. This case-driven simulation is made as the clinical status of the patient evolves, and is on the basis of step-wise decisions made during the care of this patient, according to the specific patient's needs and the logistics available at the corresponding institution.

Effects of Different Drug Combinations in Immunodeficient Mice Infected with an Influenza A/H3N2 Virus

The prolonged treatment of immunosuppressed (IS) individuals with anti-influenza monotherapies may lead to the emergence of drug-resistant variants. Herein, we evaluated oseltamivir and polymerase inhibitors combinations against influenza A/H3N2 infections in an IS mouse model. Mice were IS with cyclophosphamide and infected with 3 × 10³ PFU of a mouse-adapted A/Switzerland/9715293/2013 (H3N2) virus. Forty-eight hours post-infection, the animals started oseltamivir, favipiravir or baloxavir marboxil (BXM) as single or combined therapies for 10 days. Weight losses, survival rates and lung viral titers (LVTs) were determined. The neuraminidase (NA) and polymerase genes from lung viral samples were sequenced. All untreated animals died. Oseltamivir and favipiravir monotherapies only delayed mortality (the mean day to death (MDD) of 21.4 and 24 compared to 11.4 days for those untreated) while a synergistic improvement in survival (80%) and LVT reduction was observed in the oseltamivir/favipiravir group compared to the oseltamivir group. BXM alone or in double/triple combination provided a complete protection and significantly reduced LVTs. Oseltamivir and BXM monotherapies induced the E119V (NA) and I38T (PA) substitutions, respectively, while no resistance mutation was detected with combinations. We found that the multiple dose regimen of BXM alone provided superior benefits compared to oseltamivir and favipiravir monotherapies. Moreover, we suggest the potential for drug combinations to reduce the incidence of resistance.

Intravenous Zanamivir: A Viable Option for Critically Ill Patients With Influenza

Objective:

To review the pharmacology, clinical trial data, and clinical implications for the intravenous formulation of zanamivir.

Data Sources:

MEDLINE, PubMed, EMBASE, and Google Scholar were searched during November 2019 to July 2020. Search terms zanamivir and neuraminidase inhibitor were used.

Study Selection and Data Extraction:

All human trials and major reports from compassionate use programs with the intravenous zanamivir (IVZ) formulation were assessed and reviewed here.

Data Synthesis:

IVZ was found to be similar but not superior to oral oseltamivir in hospitalized patients when studied in populations with very low baseline oseltamivir resistance. IVZ provides an effective alternative for critically ill patients when oral antiviral therapy is not preferred or when oseltamivir resistance is increased.

Relevance to Patient Care and Clinical Practice:

IVZ was recently authorized for use by the European Medicines Agency, and it is eligible for consideration in emergency use protocols and US stockpile inclusion. It will be of particular interest in critically ill patients especially during influenza seasons with appreciable oseltamivir and peramivir resistance.

Conclusions:

The available information suggests that the intravenous formulation of zanamivir offers a viable alternative treatment for critically ill patients with influenza, especially when resistance to other agents is present.

Combination treatment with the cap-dependent endonuclease inhibitor baloxavir marboxil and a neuraminidase inhibitor in a mouse model of influenza A virus infection

Objectives

Baloxavir marboxil (formerly S-033188) is a first-in-class, orally available, cap-dependent endonuclease inhibitor licensed in Japan and the USA for the treatment of influenza virus infection. We evaluated the efficacy of delayed oral treatment with baloxavir marboxil in combination with a neuraminidase inhibitor in a mouse model of lethal influenza virus infection.

Methods

The inhibitory potency of baloxavir acid (the active form of baloxavir marboxil) in combination with neuraminidase inhibitors was tested in vitro. The therapeutic effects of baloxavir marboxil and oseltamivir phosphate, or combinations thereof, were evaluated in mice lethally infected with influenza virus A/PR/8/34; treatments started 96 h post-infection.

Results

Combinations of baloxavir acid and neuraminidase inhibitor exhibited synergistic potency against viral replication by means of inhibition of cytopathic effects in vitro. In mice, baloxavir marboxil monotherapy (15 or 50 mg/kg twice daily) significantly and dose-dependently reduced virus titre 24 h after administration and completely prevented mortality, whereas oseltamivir phosphate treatments were not as effective. In this model, a suboptimal dose of baloxavir marboxil (0.5 mg/kg twice daily) in combination with oseltamivir phosphate provided additional efficacy compared with monotherapy in terms of virus-induced mortality, elevation of cytokine/chemokine levels and pathological changes in the lung.

Conclusions

Baloxavir marboxil monotherapy with 96 h-delayed oral dosing achieved drastic reductions in virus titre, inflammatory response and mortality in a mouse model. Combination treatment with baloxavir acid and oseltamivir acid in vitro and baloxavir marboxil and oseltamivir phosphate in mice produced synergistic responses against influenza virus infections, suggesting that treating humans with the combination may be beneficial.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Invasive pulmonary aspergillosis complicating severe influenza: epidemiology, diagnosis and treatment

PURPOSE OF REVIEW

Bacterial super-infection of critically ill influenza patients is well known, but in recent years, more and more reports describe invasive aspergillosis as a frequent complication as well. This review summarizes the available literature on the association of invasive pulmonary aspergillosis (IPA) with severe influenza [influenza-associated aspergillosis (IAA)], including epidemiology, diagnostic approaches and treatment options.

RECENT FINDINGS

Though IPA typically develops in immunodeficient patients, non-classically immunocompromised patients such as critically ill influenza patients are at high-risk for IPA as well. The morbidity and mortality of IPA in these patients is high, and in the majority of them, the onset occurs early after ICU admission. At present, standard of care (SOC) consists of close follow-up of these critically ill influenza patients with high diagnostic awareness for IPA. As soon as there is clinical, mycological or radiological suspicion for IAA, antifungal azole-based therapy (e.g. voriconazole) is initiated, in combination with therapeutic drug monitoring (TDM). Antifungal treatment regimens should reflect local epidemiology of azole-resistant Aspergillus species and should be adjusted to clinical evolution. TDM is necessary as azoles like voriconazole are characterized by nonlinear pharmacokinetics, especially in critically ill patients.

SUMMARY

In light of the frequency, morbidity and mortality associated with influenza-associated aspergillosis in the ICU, a high awareness of the diagnosis and prompt initiation of antifungal therapy is required. Further studies are needed to evaluate the incidence of IAA in a prospective multicentric manner, to elucidate contributing host-derived factors to the pathogenesis of this super-infection, to further delineate the population at risk, and to identify the preferred diagnostic and management strategy, and also the role of prophylaxis.

Influenza virus-related critical illness: prevention, diagnosis, treatment

Annual seasonal influenza epidemics of variable severity result in significant morbidity and mortality in the United States (U.S.) and worldwide. In temperate climate countries, including the U.S., influenza activity peaks during the winter months. Annual influenza vaccination is recommended for all persons in the U.S. aged 6 months and older, and among those at increased risk for influenza-related complications in other parts of the world (e.g. young children, elderly). Observational studies have reported effectiveness of influenza vaccination to reduce the risks of severe disease requiring hospitalization, intensive care unit admission, and death. A diagnosis of influenza should be considered in critically ill patients admitted with complications such as exacerbation of underlying chronic comorbidities, community-acquired pneumonia, and respiratory failure during influenza season. Molecular tests are recommended for influenza testing of respiratory specimens in hospitalized patients. Antigen detection assays are not recommended in critically ill patients because of lower sensitivity; negative results of these tests should not be used to make clinical decisions, and respiratory specimens should be tested for influenza by molecular assays. Because critically ill patients with lower respiratory tract disease may have cleared influenza virus in the upper respiratory tract, but have prolonged influenza viral replication in the lower respiratory tract, an endotracheal aspirate (preferentially) or bronchoalveolar lavage fluid specimen (if collected for other diagnostic purposes) should be tested by molecular assay for detection of influenza viruses.Observational studies have reported that antiviral treatment of critically ill adult influenza patients with a neuraminidase inhibitor is associated with survival benefit. Since earlier initiation of antiviral treatment is associated with the greatest clinical benefit, standard-dose oseltamivir (75 mg twice daily in adults) for enteric administration is recommended as soon as possible as it is well absorbed in critically ill patients. Based upon observational data that suggest harms, adjunctive corticosteroid treatment is currently not recommended for children or adults hospitalized with influenza, including critically ill patients, unless clinically indicated for another reason, such as treatment of asthma or COPD exacerbation, or septic shock. A number of pharmaceutical agents are in development for treatment of severe influenza.

Influenza virus-related critical illness: prevention, diagnosis, treatment

Annual seasonal influenza epidemics of variable severity result in significant morbidity and mortality in the United States (U.S.) and worldwide. In temperate climate countries, including the U.S., influenza activity peaks during the winter months. Annual influenza vaccination is recommended for all persons in the U.S. aged 6 months and older, and among those at increased risk for influenza-related complications in other parts of the world (e.g. young children, elderly). Observational studies have reported effectiveness of influenza vaccination to reduce the risks of severe disease requiring hospitalization, intensive care unit admission, and death. A diagnosis of influenza should be considered in critically ill patients admitted with complications such as exacerbation of underlying chronic comorbidities, community-acquired pneumonia, and respiratory failure during influenza season. Molecular tests are recommended for influenza testing of respiratory specimens in hospitalized patients. Antigen detection assays are not recommended in critically ill patients because of lower sensitivity; negative results of these tests should not be used to make clinical decisions, and respiratory specimens should be tested for influenza by molecular assays. Because critically ill patients with lower respiratory tract disease may have cleared influenza virus in the upper respiratory tract, but have prolonged influenza viral replication in the lower respiratory tract, an endotracheal aspirate (preferentially) or bronchoalveolar lavage fluid specimen (if collected for other diagnostic purposes) should be tested by molecular assay for detection of influenza viruses.Observational studies have reported that antiviral treatment of critically ill adult influenza patients with a neuraminidase inhibitor is associated with survival benefit. Since earlier initiation of antiviral treatment is associated with the greatest clinical benefit, standard-dose oseltamivir (75 mg twice daily in adults) for enteric administration is recommended as soon as possible as it is well absorbed in critically ill patients. Based upon observational data that suggest harms, adjunctive corticosteroid treatment is currently not recommended for children or adults hospitalized with influenza, including critically ill patients, unless clinically indicated for another reason, such as treatment of asthma or COPD exacerbation, or septic shock. A number of pharmaceutical agents are in development for treatment of severe influenza.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Severe acute respiratory distress syndrome (ARDS) induced by human adenovirus B21: Report on 2 cases and literature review

Severe pneumonia and ARDS caused by human adenovirus B21 infections (HAdV-B21) is a rare, but a devastating disease with rapid progression to multiorgan failure and death. However, only a few cases were reported so far.

Infections appear associated with increased disease severity and higher mortality in infected critically ill patients. Possible factors contributing to infection are underlying psychiatric disease resulting in institutionalization of respective patients, and polytoxicomania. Controlled data on the therapy of severe adenovirus infections are lacking and remains experimental.

In conclusion, data on HAdV-B21 infections causing severe pneumonia or ARDS are scarce. Controlled clinical trials on the therapy of adenovirus pneumonia are non existent and thus there is no established therapy so far. ICU physicians should be aware of this potentially devastating disease and further studies are needed.

Influenza-induced rhabdomyolysis

Rhabdomyolysis is characterised by muscle breakdown with release of damaging proteins that can have devastating consequences. Acute influenza infection is being increasingly recognised as an underlying aetiology. We report an unusual case of severe rhabdomyolysis with acute renal failure due to influenza A infection that improved with high-dose oseltamivir and intravenous fluids. In our case, we also noticed a temporal relation between fever spikes and subsequent increase in serum creatine kinase. The precise mechanism between the rise in temperature and creatine kinase is unclear but it could be due to direct viral invasion of myocytes or due to release of new viral progeny following replication in the myocyte.

Pharmacokinetics of Oral and Intravenous Oseltamivir Treatment of Severe Influenza B Virus Infection Requiring Organ Replacement Therapy

BACKGROUND AND OBJECTIVES

Patients with severe influenza virus infection, multi-organ failure and organ replacement therapy may absorb and metabolize neuraminidase inhibitors differently. Systematic pharmacokinetic/pharmacodynamic clinical trials are currently lacking in this high-risk group. Inadequate dosing increases the risk of treatment failure and drug resistance, especially in severely ill patients with elevated virus loads. This study aims to explore the impact of organ replacement therapy on oseltamivir drug concentrations.

METHODS

Serial pharmacokinetic/pharmacodynamic measurements and Sieving coefficients were assessed in two patients with severe influenza B infection requiring organ replacement therapy.

RESULTS

Patient #1, a 9-year-old female with severe influenza B virus infection, biventricular assist device, and continuous veno-venous hemodiafiltration, received 75 mg oral oseltamivir twice-daily for 2 days, then intravenous oseltamivir with one-time renoprotective dosing (40 mg), followed by regular intravenous administration of 100 mg twice-daily. Plasma oseltamivir carboxylate concentrations were stable initially, but only regular administration of 100 mg resulted in virus load decline and clinical improvement. Patient #2, a 28-year-old female with influenza B virus infection requiring extracorporeal membrane oxygenation, received 75 mg oral oseltamivir twice-daily, resulting in erratic oseltamivir blood concentrations. In both patients, drug concentrations remained well within safety margins.

CONCLUSIONS

In severe cases with multi-organ failure, administration of 100 mg intravenous oseltamivir twice-daily provided reliable drug concentrations, as opposed to renoprotective and oral dosing, thereby minimizing the risk of treatment failure and drug resistance. Evidence-based pediatric dosing recommendations and effective intravenous antiviral treatment modalities are needed for intensive care patients with life-threatening influenza disease.

Influenza and the patient with end-stage renal disease

Influenza is a commonly encountered and serious pathogen. Patients with end-stage renal disease are more susceptible to serious morbidity and mortality associated with influenza infection. Proper management of patients includes: vaccination, monitoring for symptoms and isolation of potentially infected patients as well as appropriate antiviral therapies. In some cases of exposure, chemoprophylaxis is warranted. Vaccination and appropriate therapies are associated with improved outcomes.

Post-influenza aspergillosis, do not underestimate influenza B

Our objective is to highlight and focus on post-influenza aspergillosis, triggered by influenza B virus. This relatively new clinical entity is often associated with a fulminant course of respiratory decline and high mortality. A 51-year immunocompetent woman, without any medical history or risk factors for developing a complicated influenza infection, was admitted to the intensive care unit. During admission, she presented with an afebrile flu-like syndrome, myocarditis, rhabdomyolysis, multiple organ failure, and evolved to severe respiratory distress. The broncho-alveolar lavage contained influenza B RNA, and the culture revealed Aspergillus fumigatus. Despite maximal organ support, immunoglobulin, antiviral and antifungal therapy, the patient died. This case demonstrates that influenza B virus may be life threatening even to immunocompetent adults and may trigger an invasive Aspergillus superinfection.

Comparison of High-Dose Versus Standard Dose Oseltamivir in Critically Ill Patients With Influenza

Background:

Limited data support high-dose oseltamivir in critically ill patients with influenza. In several recent influenza seasons, there were oseltamivir drug shortages.

Methods:

This was a retrospective cohort analysis of 57 patients admitted to the intensive care unit (ICU) with confirmed influenza. Patients receiving high-dose oseltamivir were compared to those receiving standard dosing.

Results:

When adjusted for clinically relevant predictors of disease severity, including age, duration of therapy, Acute Physiology and Chronic Health Evaluation II score, and receipt of extracorporeal membrane oxygenation, there was no difference in the duration of mechanical ventilation, oxygenation, ICU length of stay, or hospital length of stay between the high-dose and standard dose groups.

Conclusions:

As compared to the standard doses of oseltamivir, higher-dose (ie, double dose) oseltamivir was not associated with improvement in any clinical outcomes. Using higher doses empirically on all patients during influenza season may exacerbate local drug shortages.

Influenza in the Emergency Department: Vaccination, Diagnosis, and Treatment: Clinical Practice Paper Approved by American Academy of Emergency Medicine Clinical Guidelines Committee

BACKGROUND

Influenza is an acute respiratory virus that results in significant worldwide morbidity and mortality each year. As emergency physicians, we are often the first to encounter patients with seasonal influenza. It is therefore critical that we draw on the most recent and relevant research when we make clinical decisions regarding the diagnosis, treatment, and prophylaxis of this disease.

METHODS

A MEDLINE literature search from August 2009 to August 2015 was performed using the keywords influenza vaccination efficacy AND systematic, influenza AND rapid antigen testing, and Oseltamivir AND systematic, while limiting the search to human studies written in the English language. General review articles and case reports were omitted. Each of the selected articles then underwent a structured review.

RESULTS

We identified 163 articles through our literature search, of which 68 were found to be relevant to our clinical questions. These studies then underwent a rigorous review from which recommendations were given.

CONCLUSIONS

Influenza vaccine efficacy continues to range between 40% and 80%. Vaccination has the potential to decrease disease severity and is recommended for individuals older than 6 months of age. If resources permit, vaccination can be offered to patients presenting to the emergency department. Rapid antigen detection for influenza is a simple bedside test with high specificity, but generally low sensitivity. If a patient presents with a syndrome consistent with influenza and has negative rapid antigen detection, they should either receive a confirmatory reverse transcriptase polymerase chain reaction or be treated as if they have influenza. Treatment with neuraminidase inhibitors can decrease the duration of influenza and is recommended in hospitalized patients, or in those with high risk of complications.