Features of patients that died for COVID-19 in a hospital in the south of Mexico: A observational cohort study

BACKGROUND

Due to the wide spread of SARS-CoV2 around the world, the risk of death in individuals with metabolic comorbidities has dangerously increased. Mexico has a high number of infected individuals and deaths by COVID-19 as well as an important burden of metabolic diseases; nevertheless, reports about features of Mexican individuals with COVID-19 are scarce. The aim of this study was to evaluate demographic features, clinical characteristics and the pharmacological treatment of individuals who died by COVID-19 in the south of Mexico.

METHODS

We performed an observational study including the information of 185 deceased individuals with confirmed diagnoses of COVID-19. Data were retrieved from medical records. Categorical data were expressed as proportions (%) and numerical data were expressed as mean ± standard deviation. Comorbidities and overlapping symptoms were plotted as Venn diagrams. Drug clusters were plotted as dendrograms.

RESULTS

The mean age was 59.53 years. There was a male predominance (60.1%). The mean hospital stay was 4.75 ± 4.43 days. The most frequent symptoms were dyspnea (88.77%), fever (71.42%) and dry cough (64.28%). Present comorbidities included diabetes (60.63%), hypertension (59.57%) and obesity (43.61%). The main drugs used for treating COVID-19 were azithromycin (60.6%), hydroxychloroquine (53.0%) and oseltamivir (27.3%).

CONCLUSIONS

Mexican individuals who died of COVID-19 had shorter hospital stays, higher frequency of shortness of breath, and higher prevalence of diabetes than individuals from other countries. Also, there was a high frequency of off-label use of drugs for their treatment.

Oseltamivir-Current Dosing Recommendations Reduce the Therapeutic Benefit in Patients With Mild to Moderate Renal Function and/or Large Body Mass: A Review of the Literature With Recommendations to Optimize Dosing, Including the Use of Therapeutic Drug Monitoring

PURPOSE

Oseltamivir is indicated for the treatment and prophylaxis of influenza infections. Achieving therapeutic concentrations EARLY in the course of the infection impacts greatly on the magnitude of benefit. Oseltamivir is renally cleared and dose reductions are advised for patients with renal impairment. The purpose of this review was to determine whether these dose reductions facilitate the early attainment of therapeutic concentrations. The review also examined the effect of body mass on the same outcome.

METHOD

Oseltamivir is administered as a prodrug and converted to the active carboxylate moiety in the liver. Published articles that included oseltamivir carboxylate (OC) pharmacokinetics in patients with renal impairment and those with large body mass were reviewed. Concentrations of OC achieved in the first 24 hours were compared with those from patients with normal renal function and body mass.

RESULTS

Studies that informed dosage regimens for patients with mild to moderately impaired renal function focused on attaining steady-state concentrations similar to those observed in patients with normal renal function. They overlooked the importance of achieving therapeutic concentrations EARLY in the course of the infection. As a result, many patients will not attain therapeutic concentrations until too late in the infection. This is also true for patients with a large body mass.

CONCLUSIONS

Current dosing advice for oseltamivir in patients with mild to moderate renal impairment and those with a larger body mass are likely to reduce (or even negate) its efficacy. The first dose should be 75 mg for patients with normal body mass and proportionately larger when body mass is larger. Subsequent doses should be reduced in proportion to the degree of renal impairment. Timely therapeutic drug monitoring can provide invaluable dosing (and other) information to the clinician treating patients with influenza and could improve patient outcomes.

Efficacy comparison of oseltamivir alone and oseltamivir-antibiotic combination for early resolution of symptoms of severe influenza-A and influenza-B hospitalized patients

Objectives:

To assess the comparative efficacy of oseltamivir alone and oseltamivir-antibiotic therapy for early relief of symptoms associated with severe influenza-A (non-H1N1) and influenza-B infection hospitalized patients.

Methods:

In this retrospective multicenter study conducted from 2016-2019, enrolled patients were divided into 2 treatment groups. Group 1 patients were started on Antiviral drug (oseltamivir) alone therapy. Group 2 patients were initiated on Antiviral drug (oseltamivir) in combination with Antibiotic therapy. Using acute respiratory illness scoring, symptom severity score was assessed daily for 8 symptoms namely, fever, fatigue, headache, cough, sore throat, wheezing, muscle ache and nasal congestion. For each symptom the severity was scored from scale 0-3.

Results:

Overall mean ARI severity score was statistically significantly lower (p<0.05) on day 2 (14.65-vs-13.68), day 3 (12.95-vs-11.67) and day 4 (10.31-vs-9.12 ) for influenza-A (non-H1N1) while day 3 (12.52-vs-11.87) and day 4 (11.21-vs-10.18) for influenza-B patients for patients who were initiated on oseltamivir-antibiotic combination therapy. Fever, cough and nasal congestion showed statistically significant improvement within 4 days of initiation of combination treatment. Fatigue, sore throat and muscle ache improvement pattern was same for both treatment protocols.

Conclusion:

Oseltamivir-antibiotic combination treatment showed early resolution of some symptoms with cumulatively reduced mean symptom severity score in severe influenza infection hospitalized patients.

The clinical value of two combination regimens in the Management of Patients Suffering from Covid-19 pneumonia: a single centered, retrospective, observational study

BACKGROUND

There is no identified pharmacological therapy for COVID-19 patients, where potential therapeutic strategies are underway to determine effective therapy under such unprecedented pandemic. Therefore, combination therapies may have the potential of alleviating the patient's outcome. This study aimed at comparing the efficacy of two different combination regimens in improving outcomes of patients infected by novel coronavirus (COVID-19).

METHODS

This is a single centered, retrospective, observational study of 60 laboratory-confirmed COVID-19 positive inpatients (≥18 years old) at two wards of the Baqiyatallah Hospital, Tehran, Iran. Patient's data including clinical and laboratory parameters were recorded. According to the drug regimen, the patients were divided into two groups; group I who received regimen I consisting azithromycin, prednisolone, naproxen, and lopinavir/ritonavir and group II who received regimen II including meropenem, levofloxacin, vancomycin, hydroxychloroquine, and oseltamivir.

RESULTS

The oxygen saturation (SpO2) and temperature were positively changed in patients receiving regimen I compared to regimen II (P = 0.013 and P = 0.012, respectively). The serum level of C-reactive protein (CRP) changed positively in group I (P < 0.001). Although there was a significant difference in platelets between both groups (75.44 vs 51.62, P < 0.001), their change did not clinically differ between two groups. The findings indicated a significant difference of the average length of stay in hospitals (ALOS) between two groups, where the patients under regimen I showed a shorter ALOS (6.97 vs 9.93, P = 0.001).

CONCLUSION

This study revealed the beneficial effect of the short-term use of low-dose prednisolone in combination with azithromycin, naproxen and lopinavir/ritonavir (regimen I), in decreasing ALOS compared to regimen II. Since there is still lack of evidence for safety of this regimen, further investigation in our ongoing follow-up to deal with COVID-19 pneumonia is underway. Graphical abstract.

Phase 2a, open-label, dose-escalating, multi-center pharmacokinetic study of favipiravir (T-705) in combination with oseltamivir in patients with severe influenza

BACKGROUND

The pharmacokinetics and appropriate dose regimens of favipiravir are unknown in hospitalized influenza patients; such data are also needed to determine dosage selection for favipiravir trials in COVID-19.

METHODS

In this dose-escalating study, favipiravir pharmacokinetics and tolerability were assessed in critically ill influenza patients. Participants received one of two dosing regimens; Japan licensed dose (1600 mg BID on day 1 and 600 mg BID on the following days) and the higher dose (1800 mg/800 mg BID) trialed in uncomplicated influenza. The primary pharmacokinetic endpoint was the proportion of patients with a minimum observed plasma trough concentration (Ctrough) ≥20 mg/L at all measured time points after the second dose.

RESULTS

Sixteen patients were enrolled into the low dose group and 19 patients into the high dose group of the study. Favipiravir Ctrough decreased significantly over time in both groups (p <0.01). Relative to day 2 (48 hrs), concentrations were 91.7% and 90.3% lower in the 1600/600 mg group and 79.3% and 89.5% lower in the 1800/800 mg group at day 7 and 10, respectively. In contrast, oseltamivir concentrations did not change significantly over time. A 2-compartment disposition model with first-order absorption and elimination described the observed favipiravir concentration-time data well. Modeling demonstrated that less than 50% of patients achieved Ctrough ≥20 mg/L for >80% of the duration of treatment of the two dose regimens evaluated (18.8% and 42.1% of patients for low and high dose regimen, respectively). Increasing the favipravir dosage predicted a higher proportion of patients reaching this threshold of 20 mg/L, suggesting that dosing regimens of ≥3600/2600 mg might be required for adequate concentrations. The two dosing regimens were well-tolerated in critical ill patients with influenza.

CONCLUSION

The two dosing regimens proposed for uncomplicated influenza did not achieve our pre-defined treatment threshold.

Oseltamivir plus usual care versus usual care for influenza-like illness in primary care: an open-label, pragmatic, randomised controlled trial

BACKGROUND

Antivirals are infrequently prescribed in European primary care for influenza-like illness, mostly because of perceived ineffectiveness in real world primary care and because individuals who will especially benefit have not been identified in independent trials. We aimed to determine whether adding antiviral treatment to usual primary care for patients with influenza-like illness reduces time to recovery overall and in key subgroups.

METHODS

We did an open-label, pragmatic, adaptive, randomised controlled trial of adding oseltamivir to usual care in patients aged 1 year and older presenting with influenza-like illness in primary care. The primary endpoint was time to recovery, defined as return to usual activities, with fever, headache, and muscle ache minor or absent. The trial was designed and powered to assess oseltamivir benefit overall and in 36 prespecified subgroups defined by age, comorbidity, previous symptom duration, and symptom severity, using a Bayesian piece-wise exponential primary analysis model. The trial is registered with the ISRCTN Registry, number ISRCTN 27908921.

FINDINGS

Between Jan 15, 2016, and April 12, 2018, we recruited 3266 participants in 15 European countries during three seasonal influenza seasons, allocated 1629 to usual care plus oseltamivir and 1637 to usual care, and ascertained the primary outcome in 1533 (94%) and 1526 (93%). 1590 (52%) of 3059 participants had PCR-confirmed influenza infection. Time to recovery was shorter in participants randomly assigned to oseltamivir (hazard ratio 1·29, 95% Bayesian credible interval [BCrI] 1·20-1·39) overall and in 30 of the 36 prespecified subgroups, with estimated hazard ratios ranging from 1·13 to 1·72. The estimated absolute mean benefit from oseltamivir was 1·02 days (95% [BCrI] 0·74-1·31) overall, and in the prespecified subgroups, ranged from 0·70 (95% BCrI 0·30-1·20) in patients younger than 12 years, with less severe symptoms, no comorbidities, and shorter previous illness duration to 3·20 (95% BCrI 1·00-5·50) in patients aged 65 years or older who had more severe illness, comorbidities, and longer previous illness duration. Regarding harms, an increased burden of vomiting or nausea was observed in the oseltamivir group.

INTERPRETATION

Primary care patients with influenza-like illness treated with oseltamivir recovered one day sooner on average than those managed by usual care alone. Older, sicker patients with comorbidities and longer previous symptom duration recovered 2-3 days sooner.

FUNDING

European Commission's Seventh Framework Programme.

Toll-like receptor 5 agonist flagellin reduces influenza A virus replication independently of type I interferon and interleukin 22 and improves antiviral efficacy of oseltamivir

Influenza infections remain a burden on health care systems despite vaccination programs and marketed antiviral drugs. Immunomodulation through activation of innate sensors could represent innovative approaches to fight the flu. This study evaluated the ability of flagellin, agonist of Toll-like receptor 5 (TLR5), to control the replication of influenza A virus (IAV) in mice. First, we showed that systemic or intranasal administration of flagellin activated transcription of anti-viral genes in lung tissue. Prophylactic and therapeutic flagellin administration resulted in decreased levels of viral RNA and infectious virus in the lungs of H3N2 IAV-infected mice. The effect of the flagellin on viral replication was also observed in Ifnar-/- and Il22-/- IAV-infected mice, suggesting a mechanism independent of type I interferon and interleukin 22 signaling. In addition, a combination therapy associating the neuraminidase inhibitor oseltamivir and flagellin was more effective than standalone treatments in reducing pulmonary viral replication. Thus, this study highlights the therapeutic potential of the flagellin to control the replication of the influenza virus.

Compatibility of Baclofen, Carvedilol, Hydrochlorothiazide, Mercaptopurine, Methadone Hydrochloride, Oseltamivir Phosphate, Phenobarbital, Propranolol Hydrochloride, Pyrazinamide, Sotalol Hydrochloride, Spironolactone, Tacrolimus Monohydrate, Ursodeoxycholic Acid, and Vancomycin Hydrochloride Oral Suspensions Compounded with SyrSpend SF pH4

Compounded liquid medication is frequently required in children to allow easy dose adjustment and overcome swallowing difficulties. The objective of this study was to evaluate the stability of oral suspensions compounded with SyrSpend SF PH4 and the commonly used active pharmaceutical ingredients baclofen 2.0 mg/mL, carvedilol 5.0 mg/mL, hydrochlorothiazide 2.0 mg/mL, mercaptopurine 10.0 mg/mL, methadone hydrochloride 10.0 mg/mL, oseltamivir phosphate 6.0 mg/mL, phenobarbital 9.0 mg/mL and 15.0 mg/mL, propranolol hydrochloride 0.5 mg/mL and 5.0 mg/mL, pyrazinamide 100.0 mg/mL, spironolactone 2.0 mg/mL and 2.5 mg/mL, sotalol hydrochloride 5.0 mg/mL, tacrolimus monohydrate 0.5 mg/mL, ursodeoxycholic acid 20.0 mg/mL, and vancomycin hydrochloride 25.0 mg/mL. Suspensions were compounded with raw powders, except for mercaptopurine, pyrazinamide, and sotalol hydrochloride, which were made from commercial tablets. Stability was assessed by measuring the percentage recovery at 0 (baseline), 60 days, and 90 days after compounding for suspensions made with raw powders, which were stored at 2ÅãC to 8ÅãC. The stability of tablets, which were stored at 2ÅãC to 8ÅãC and 20ÅãC to 25ÅãC, was assessed by measuring the percentage recovery at 0 (baseline), 7 days, 14 days, 30 days, 60 days, and 90 days. Active pharmaceutical ingredients quantification was performed by ultraviolet high-performance liquid chromatography via a stability-indicating method. Given the percentage of recovery of the active pharmaceutical ingredients within the suspensions, the beyond-use date of the final products (active pharmaceutical ingredients + vehicle) was at least 90 days for all suspensions in the conditions tested. This suggests that SyrSpend SF PH4 is suitable for compounding active pharmaceutical ingredients from different pharmacological classes.

Evaluation of Drug-Drug Interaction Potential between Baloxavir Marboxil and Oseltamivir in Healthy Subjects

BACKGROUND AND OBJECTIVE

Baloxavir marboxil is a prodrug that is metabolized to baloxavir acid, which suppresses viral replication by inhibiting cap-dependent endonuclease with a single oral administration. As the mode of action of baloxavir marboxil is different from that of neuraminidase inhibitors, such as oseltamivir, combination treatment with these drugs can be a treatment option, particularly for severe influenza infection. The aim of this study was to assess the drug-drug interaction between baloxavir marboxil and oseltamivir.

METHODS

Eighteen healthy adult subjects received three treatments in a crossover fashion: single administration of baloxavir marboxil 40 mg alone, repeated twice-daily administration of oseltamivir at 75 mg for 5 days, or single administration of baloxavir marboxil at 40 mg in combination with repeated twice-daily administration of oseltamivir at 75 mg for 5 days.

RESULTS

The ratios (90% confidence intervals) of maximum plasma concentration and area under the plasma concentration-time curve of baloxavir acid after co-administration compared to baloxavir marboxil alone were 1.03 (0.92-1.15) and 1.01 (0.96-1.06), respectively. The ratios (90% confidence intervals) of maximum plasma concentration and area under the plasma concentration-time curve of oseltamivir carboxylate, the active form of oseltamivir, after co-administration compared to oseltamivir alone were 0.96 (0.93-1.00) and 0.99 (0.96-1.01), respectively, at steady state on day 5. Treatment-emergent adverse events reported were mild and not considered to be related to the study drug.

CONCLUSION

The lack of a clinically meaningful drug-drug interaction between baloxavir marboxil and oseltamivir has been established.

Clinical effectiveness of four neuraminidase inhibitors (oseltamivir, zanamivir, laninamivir, and peramivir) for children with influenza A and B in the 2014-2015 to 2016-2017 influenza seasons in Japan

The clinical effectiveness of four neuraminidase inhibitors (NAIs) (oseltamivir, zanamivir, laninamivir, and peramivir) for children aged 0 months to 18 years with influenza A and B were investigated in the 2014-2015 to 2016-2017 influenza seasons in Japan. A total of 1207 patients (747 with influenza A and 460 with influenza B) were enrolled. The Cox proportional-hazards model using all of the patients showed that the duration of fever after administration of the first dose of the NAI was shorter in older patients (hazard ratio = 1.06 per 1 year of age, p < 0.001) and that the duration of fever after administration of the first dose of the NAI was shorter in patients with influenza A infection than in patients with influenza B infection (hazard ratio = 2.21, p < 0.001). A logistic regression model showed that the number of biphasic fever episodes was 2.99-times greater for influenza B-infected patients than for influenza A-infected patients (p < 0.001). The number of biphasic fever episodes in influenza A- or B-infected patients aged 0-4 years was 2.89-times greater than that in patients aged 10-18 years (p = 0.010), and the number of episodes in influenza A- or B-infected patients aged 5-9 years was 2.13-times greater than that in patients aged 10-18 years (p = 0.012).

The anti-influenza drug oseltamivir evokes hypothermia in mice through dopamine D2 receptor activation via central actions

Oseltamivir has a hypothermic effect in mice when injected intraperitoneally (i.p.) and intracerebroventricularly (i.c.v.). Here we show that the hypothermia evoked by i.c.v.-oseltamivir is inhibited by non-selective dopamine receptor antagonists (sulpiride and haloperidol) and the D₂-selective antagonist L-741,626, but not by D₁/D₅-selective and D₃-selective antagonists (SCH-23390 and SB-277011-A, respectively). The hypothermic effect of i.p.-administered oseltamivir was not inhibited by sulpiride, haloperidol, L-741,626 and SCH-23390. In addition, neither sulpiride, haloperidol nor SCH-23390 blocked hypothermia evoked by i.c.v.-administered oseltamivir carboxylate (a hydrolyzed metabolite of oseltamivir). These results suggest that oseltamivir in the brain induces hypothermia through activation of dopamine D₂ receptors.

Oseltamivir, amantadine, and ribavirin combination antiviral therapy versus oseltamivir monotherapy for the treatment of influenza: a multicentre, double-blind, randomised phase 2 trial

BACKGROUND

Influenza continues to have a substantial socioeconomic and health impact despite a long established vaccination programme and approved antivirals. Preclinical data suggest that combining antivirals might be more effective than administering oseltamivir alone in the treatment of influenza.

METHODS

We did a randomised, double-blind, multicentre phase 2 trial of a combination of oseltamivir, amantadine, and ribavirin versus oseltamivir monotherapy with matching placebo for the treatment of influenza in 50 sites, consisting of academic medical centre clinics, emergency rooms, and private physician offices in the USA, Thailand, Mexico, Argentina, and Australia. Participants who were aged at least 18 years with influenza and were at increased risk of complications were randomly assigned (1:1) by an online computer-generated randomisation system to receive either oseltamivir (75 mg), amantadine (100 mg), and ribavirin (600 mg) combination therapy or oseltamivir monotherapy twice daily for 5 days, given orally, and participants were followed up for 28 days. Blinded treatment kits were used to achieve masking of patients and staff. The primary endpoint was the percentage of participants with virus detectable by PCR in nasopharyngeal swab at day 3, and was assessed in participants who were randomised, had influenza infection confirmed by the central laboratory on a baseline nasopharyngeal sample, and had received at least one dose of study drug. Safety assessment was done in all patients in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01227967.

FINDINGS

Between March 1, 2011, and April 29, 2016, 633 participants were randomly assigned to receive combination antiviral therapy (n=316) or monotherapy (n=317). Seven participants were excluded from analysis: three were not properly randomised, three withdrew from the study, and one was lost to follow-up. The primary analysis included 394 participants, excluding 47 in the pilot phase, 172 without confirmed influenza, and 13 without an endpoint sample. 80 (40·0%) of 200 participants in the combination group had detectable virus at day 3 compared with 97 (50·0%) of 194 (mean difference 10·0, 95% CI 0·2-19·8, p=0·046) in the monotherapy group. The most common adverse events were gastrointestinal-related disorders, primarily nausea (65 [12%] of 556 reported adverse events in the combination group vs 63 [11%] of 585 reported adverse events in the monotherapy group), diarrhoea (56 [10%] of 556 vs 64 [11%] of 585), and vomiting (39 [7%] of 556 vs 23 [4%] of 585). There was no benefit in multiple clinical secondary endpoints, such as median duration of symptoms (4·5 days in the combination group vs 4·0 days in the monotherapy group; p=0·21). One death occurred in the study in an elderly participant in the monotherapy group who died of cardiovascular failure 13 days after randomisation, judged by the site investigator as not related to study intervention.

INTERPRETATION

Although combination treatment showed a significant decrease in viral shedding at day 3 relative to monotherapy, this difference was not associated with improved clinical benefit. More work is needed to understand why there was no clinical benefit when a difference in virological outcome was identified.

FUNDING

National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA.

Factors associated with non-persistence to oral and inhaled antiviral therapies for seasonal influenza: a secondary analysis of a double-blind, multicentre, randomised clinical trial

OBJECTIVES

We aimed to evaluate and compare non-adherence to oral and inhaled antiviral therapies prescribed of a randomised clinical trial in outpatients with influenza A infection.

DESIGN

A parallel, three-arm, double-blinded trial randomly allocated antiviral therapies twice daily for 5 days: (1) oral oseltamivir plus inhaled zanamivir (arm OZ); (2) oseltamivir plus inhaled placebo (arm Opz); or (3) oral placebo plus inhaled zanamivir (arm poZ). Analysis of non-adherence was a secondary objective of the trial.

SETTINGS

Outpatients were enrolled by 145 general practitioners throughout France during the 2008-2009 seasonal influenza epidemics.

PARTICIPANTS

A total of 541 adults presenting with influenza-like illness for less than 36 hours.

PRIMARY OUTCOMES

Non-persistence, the time between inclusion and the last dose treated as a failure time, was used as the primary endpoint.

RESULTS

The proportions of patients who persisted on treatment until the end of prescription were estimated at 85.73% (±3.28%) for the oral route and 82.73% (±3.44%) for the inhaled route. Based on multivariable models, non-persistence was associated with a PCR confirmation of influenza for both the oral (HR=0.54, p=0.010) and inhaled (HR=0.59, p=0.018) drugs and antibiotic coprescriptions (HR=2.07, p=0.007; and HR=1.88, p=0.017, respectively) and active combination treatment (HR=1.71, p=0.035; and HR=1.58, p=0.035, respectively). The hazard of non-persistence of the inhaled therapy was increased compared with that of the oral therapy (HR=1.23, p=0.043).

CONCLUSION

In addition to the clinical and virological profiles of influenza infection, non-persistence may have been influenced by an active combination and the route of administration.

RCT REGISTRATION NUMBER

NCT00799760. This is a post-result analysis.

Comparison of Efficacy of Intravenous Peramivir and Oral Oseltamivir for the Treatment of Influenza: Systematic Review and Meta-Analysis

PURPOSE

Peramivir is the first intravenously administered neuramidase inhibitor for immediate delivery of an effective single-dose treatment in patients with influenza. However, limited data are available on intravenous (IV) peramivir treatment compared to oral oseltamivir for these patients.

MATERIALS AND METHODS

With a systematic review and meta-analysis, we compared the efficacy of IV peramivir with oral oseltamivir for treatment of patients with seasonal influenza. MEDLINE, EMBASE, and Cochrane Central Register were searched for relevant clinical trials.

RESULTS

A total of seven trials [two randomized controlled trials (RCTs) and five non-randomized observational trials] involving 1676 patients were finally analyzed. The total number of peramivir- and oseltamivir-treated patients was 956 and 720, respectively. Overall, the time to alleviation of fever was lower in the peramivir-treated group compared with the oseltamivir-treated group [mean difference (MD), -7.17 hours; 95% confidence interval (CI) -11.00 to -3.34]. Especially, pooled analysis of observational studies (n=4) and studies of outpatients (n=4) demonstrated the superiority of the peramivir-treated group (MD, -7.83 hours; 95% CI -11.81 to -3.84 and MD, -7.71 hours; 95% CI -11.61 to -3.80, respectively). Mortality, length of hospital stay, change in virus titer 48 hours after admission, and the incidence of adverse events in these patients were not significantly different between the two groups.

CONCLUSION

IV peramivir therapy might reduce the time to alleviation of fever in comparison with oral oseltamivir therapy in patients with influenza; however, we could not draw clear conclusions from a meta-analysis because of the few RCTs available and methodological limitations.

Anti-inflammatory effects of adjunctive macrolide treatment in adults hospitalized with influenza: A randomized controlled trial

INTRODUCTION

- Macrolides can ameliorate inflammation in respiratory diseases, providing clinical benefits. Data in influenza is lacking.

METHOD

- A randomized, open-label, multicenter trial among adults hospitalized for laboratory-confirmed influenza was conducted. Study treatments of oseltamivir and azithromycin (500 mg/day), or oseltamivir alone, both for 5 days, were allocated at 1:1 ratio. The primary outcome was plasma cytokine/chemokine concentration change over time (Day 0-10); secondary outcomes were viral load and symptom score changes. Generalized Estimating Equation (GEE) models were used to analyze longitudinal data.

RESULTS

- Fifty patients were randomized to the oseltamivir-azithromycin or oseltamivir groups, with comparable baseline characteristics (age, 57 ± 18 years; A/H3N2, 70%), complications (72%), and viral load. Pro-inflammatory cytokines IL-6 (GEE: β -0.037, 95%CI-0.067,-0.007, P = 0.016; reduction from baseline -83.4% vs -59.5%), CXCL8/IL-8 (β -0.018, 95%CI-0.037,0.000, P = 0.056; -80.5% vs -58.0%), IL-17 (β -0.064, 95%CI-0.117,-0.012, P = 0.015; -74.0% vs -34.3%), CXCL9/MIG (β -0.010, 95%CI-0.020,0.000, P = 0.043; -71.3% vs -56.0%), sTNFR-1, IL-18, and CRP declined faster in the oseltamivir-azithromycin group. There was a trend toward faster symptom resolution (β -0.463, 95%CI-1.297,0.371). Viral RNA decline (P = 0.777) and culture-negativity rates were unaffected. Additional ex vivo studies confirmed reduced induction of IL-6 (P = 0.017) and CXCL8/IL-8 (P = 0.005) with azithromycin.

CONCLUSION

- We found significant anti-inflammatory effects with adjunctive macrolide treatment in adults with severe influenza infections. Virus control was unimpaired. Clinical benefits of a macrolide-containing regimen deserve further study. [ClinicalTrials.gov NCT01779570].

Intravenous zanamivir or oral oseltamivir for hospitalised patients with influenza: an international, randomised, double-blind, double-dummy, phase 3 trial

BACKGROUND

Neuraminidase inhibitors are effective for the treatment of acute uncomplicated influenza. However, there is an unmet need for intravenous treatment for patients admitted to hospital with severe influenza. We studied whether intravenous zanamivir was a suitable treatment in this setting.

METHODS

In this international, randomised, double-blind, double-dummy, phase 3 trial, we recruited patients aged 16 years or older with severe influenza admitted to 97 hospitals from 26 countries. We randomly assigned patients (1:1:1 stratified by symptom onset ≤4 days or 5-6 days) to receive 300 mg or 600 mg intravenous zanamivir, or standard-of-care (75 mg oral oseltamivir) twice a day for 5-10 days; patients were followed up for 28 days. The randomisation schedule, including stratification, was generated using GlaxoSmithKline's RandAll software. Patients, site study staff, and sponsor were masked to study treatment. The primary endpoint was time to clinical response-a composite of vital sign stabilisation and hospital discharge-in the influenza-positive population. The trial was powered to show an improvement of 1·5 days or greater with 600 mg intravenous zanamivir. Pharmacokinetic, safety, and virology endpoints were also assessed. This trial is registered with ClinicalTrials.gov, number NCT01231620.

FINDINGS

Between Jan 15, 2011, and Feb 12, 2015, 626 patients were randomly assigned to receive 300 mg intravenous zanamivir (n=201), 600 mg intravenous zanamivir (n=209), or 75 mg oral oseltamivir (n=205) twice a day; 11 patients discontinued the study before receiving any study treatment. 488 (78%) of 626 patients had laboratory-confirmed influenza. Compared with a median time to clinical response of 5·14 days in the 600 mg intravenous zanamivir group, the median time to clinical response was 5·87 days (difference of -0·73 days, 95% CI -1·79 to 0·75; p=0·25) in the 300 mg intravenous zanamivir group and 5·63 days (difference of -0·48 days, 95% CI -2·11 to 0·97; p=0·39) in the oseltamivir group. Four patients with influenza A/H1N1pdm09 in the oseltamivir group developed H275Y resistance mutations. Adverse events were reported in 373 (61%) of treated patients and were similar across treatment groups; the most common adverse events (300 mg intravenous zanamivir, 600 mg intravenous zanamivir, oseltamivir) were diarrhoea (10 [5%], 15 [7%], 14 [7%]), respiratory failure (11 [5%], 14 [7%], 11 [5%]), and constipation (7 [3%], 13 [6%], 10 [5%]). 41 (7%) treated patients died during the study (15 [7%], 15 [7%], 11 [5%]); the most common causes of death were respiratory failure and septic shock.

INTERPRETATION

Time to clinical response to intravenous zanamivir dosed at 600 mg was not superior to oseltamivir or 300 mg intravenous zanamivir. All treatments had a similar safety profile in hospitalised patients with severe influenza.

FUNDING

GlaxoSmithKline.

Forsythoside A Controls Influenza A Virus Infection and Improves the Prognosis by Inhibiting Virus Replication in Mice

OBJECTIVE

The objective of this study was to observe the effects of forsythoside A on controlling influenza A virus (IAV) infection and improving the prognosis of IAV infection.

METHODS

Forty-eight SPF C57BL/6j mice were randomly divided into the following four groups: Group A: normal control group (normal con); Group B: IAV control group (V con); Group C: IAV+ oseltamivir treatment group (V oseltamivir; 0.78 mg/mL, 0.2 mL/mouse/day); Group D: IAV+ forsythoside A treatment group (V FTA; 2 μg/mL, 0.2 mL/mouse/day). Real-time fluorescence quantitative PCR (RT-qPCR) was used to measure mRNA expression of the TLR7, MyD88, TRAF6, IRAK4 and NF-κB p65 mRNA in TLR7 signaling pathway and the virus replication level in lung. Western blot was used to measure TLR7, MyD88 and NF-κB p65 protein. Flow cytometry was used to detect the proportion of the T cell subsets Th1/Th2 and Th17/Treg.

RESULTS

The body weight began to decrease after IAV infection, while FTA and oseltamivir could reduce the rate of body weight loss. The pathological damages in the FTA and oseltamivir group were less serious. TLR7, MyD88, TRAF6, IRAK4 and NF-κB p65 mRNA were up-regulated after virus infection (p < 0.01) while down-regulated after oseltamivir and FTA treatment (p < 0.01). The results of TLR7, MyD88 and NF-κB p65 protein consisted with correlative mRNA. Flow cytometry showed the Th1/Th2 differentiated towards Th2, and the Th17/Treg cells differentiated towards Treg after FTA treatment.

CONCLUSIONS

Our study suggests forsythoside A can control influenza A virus infection and improve the prognosis of IAV infection by inhibiting influenza A virus replication.

Oseltamivir Population Pharmacokinetics in the Ferret: Model Application for Pharmacokinetic/Pharmacodynamic Study Design

The ferret is a suitable small animal model for preclinical evaluation of efficacy of antiviral drugs against various influenza strains, including highly pathogenic H5N1 viruses. Rigorous pharmacokinetics/pharmacodynamics (PK/PD) assessment of ferret data has not been conducted, perhaps due to insufficient information on oseltamivir PK. Here, based on PK data from several studies on both uninfected and influenza-infected groups (i.e., with influenza A viruses of H5N1 and H3N2 subtypes and an influenza B virus) and several types of anesthesia we developed a population PK model for the active compound oseltamivir carboxylate (OC) in the ferret. The ferret OC population PK model incorporated delayed first-order input, two-compartment distribution, and first-order elimination to successfully describe OC PK. Influenza infection did not affect model parameters, but anesthesia did. The conclusion that OC PK was not influenced by influenza infection must be viewed with caution because the influenza infections in the studies included here resulted in mild clinical symptoms in terms of temperature, body weight, and activity scores. Monte Carlo simulations were used to determine that administration of a 5.08 mg/kg dose of oseltamivir phosphate to ferret every 12 h for 5 days results in the same median OC area under the plasma concentration-time curve 0–12 h (i.e., 3220 mg h/mL) as that observed in humans during steady state at the approved dose of 75 mg twice daily for 5 days. Modeling indicated that PK variability for OC in the ferret model is high, and can be affected by anesthesia. Therefore, for proper interpretation of PK/PD data, sparse PK sampling to allow the OC PK determination in individual animals is important. Another consideration in appropriate design of PK/PD studies is achieving an influenza infection with pronounced clinical symptoms and efficient virus replication, which will allow adequate evaluation of drug effects.

[EFFECTIVENESS OF FULLERENE-(TRIS-AMINOCAPRONIC ACID) HYDRATE IN THE MODEL OF EXPERIMENTAL VIRAL-BACTERIAL PNEUMONIA OF MICE]

AIM

Study the effectiveness of the substance and various drug formulations of fullerene-(tris-aminocapronic acid) hydrate (FTAAH onwards) in the model of experimental viral-bacterial pneumonia of mice.

MATERIALS AND METHODS

BALB/c mice were infected with influenza virus A/California/04/2009 and subsequently infected with Staphylococcus aureus. The animals were treated after viral infection with the substance and various drug forms of FTAAH, as well as comparative preparations--oseltamivir and arbidol. Therapy effectiveness was evaluated by clinical indicators (survival, lifespan, animal mass decrease reduction), virological (virus titer), microbiological (density of bacteria in lungs) parameters, confirmed by pathomorphological characteristics of lungs.

RESULTS

FTAAH therapy in injectable form was effective in the model of a combined viral-bacterial pneumonia of mice by all the studied criteria: treatment increased mice survival, reduced the decrease of their body weight, resulted in a reduction of virus titers and density of bacteria in lungs, that correlated with the data from morphological study and signs of bronchopneumonia resolution in mice. FTAAH therapy in rectal form depended on animal infection schemes, as well as preparation dose, increasing with its increase.

CONCLUSION

FTAAH substance is effective in the model of experimental viral-bacterial pneumonia of mice.

Prompt Oseltamivir Therapy Reduces Medical Care and Mortality for Patients With Influenza Infection: An Asian Population Cohort Study

There are limited population-based studies on the progress of oseltamivir therapy for influenza infection.Using insurance claims data of 2005, 2009, and 2010, the authors established an "in-time" cohort and a "lag-time" cohort representing influenza patients taking the medicine within and not within 1 week to examine the treatment progress. Incident outpatient visit, emergency care and hospitalization, and fatality were compared between the 2 cohorts in the first week and the second week of follow-up periods, after the oseltamivir therapy.A total of 112,492 subjects diagnosed with influenza on oseltamivir therapy in 2005, 2009, and 2010 were identified. The multivariate logistic regression analysis showed that the in-time treatment was superior to the lag-time treatment with less repeat outpatient visits, hospitalizations, and fatality. The overall corresponding in-time treatment to lag-time treatment odds ratios (OR) were 0.50, 0.54, and 0.71 (all P value < 0.05), respectively. The in-time to lag-time ORs of all events were 0.50 in 2009 and 0.54 in 2010.Our study demonstrates that the in-time oseltamivir therapy leads to significantly better treatment outcomes. Oseltamivir should be administered as early as the onset of influenza symptoms appears.

A GFP expressing influenza A virus to report in vivo tropism and protection by a matrix protein 2 ectodomain-specific monoclonal antibody

The severity of influenza-related illness is mediated by many factors, including in vivo cell tropism, timing and magnitude of the immune response, and presence of pre-existing immunity. A direct way to study cell tropism and virus spread in vivo is with an influenza virus expressing a reporter gene. However, reporter gene-expressing influenza viruses are often attenuated in vivo and may be genetically unstable. Here, we describe the generation of an influenza A virus expressing GFP from a tri-cistronic NS segment. To reduce the size of this engineered gene segment, we used a truncated NS1 protein of 73 amino acids combined with a heterologous dimerization domain to increase protein stability. GFP and nuclear export protein coding information were fused in frame with the truncated NS1 open reading frame and separated from each other by 2A self-processing sites. The resulting PR8-NS1(1–73)GFP virus was successfully rescued and replicated as efficiently as the parental PR8 virus in vitro and was slightly attenuated in vivo. Flow cytometry-based monitoring of cells isolated from PR8-NS1(1–73)GFP virus infected BALB/c mice revealed that GFP expression peaked on day two in all cell types tested. In particular respiratory epithelial cells and myeloid cells known to be involved in antigen presentation, including dendritic cells (CD11c⁺) and inflammatory monocytes (CD11b⁺ GR1⁺), became GFP positive following infection. Prophylactic treatment with anti-M2e monoclonal antibody or oseltamivir reduced GFP expression in all cell types studied, demonstrating the usefulness of this reporter virus to analyze the efficacy of antiviral treatments in vivo. Finally, deep sequencing analysis, serial in vitro passages and ex vivo analysis of PR8-NS1(1–73)GFP virus, indicate that this virus is genetically and phenotypically stable.

Intravenous peramivir inhibits viral replication, and leads to bacterial clearance and prevention of mortality during murine bacterial co-infection caused by influenza A(H1N1)pdm09 virus and Streptococcus pneumoniae

INTRODUCTION

Influenza virus infection increases susceptibility to bacterial infection and mortality in humans. Although the efficacy of approved intravenous peramivir, a neuraminidase (NA) inhibitor, against influenza virus infection has been reported, its efficacy against bacterial co-infection, which occurs during the period of viral shedding, was not fully investigated. To further understand the significance of treatment with peramivir, we assessed the efficacy of peramivir against a bacterial co-infection model in mice caused by clinically isolated influenza A(H1N1)pdm09 virus and Streptococcus pneumoniae.

METHODS

Mice were infected with influenza A(H1N1)pdm09. Peramivir was intravenously administered after the viral infection. At 2days post viral infection, the mice were infected with S. pneumoniae. Peramivir efficacy was measured by the survival rates and viral titers, bacterial titers, or proinflammatory cytokine concentrations in lung homogenates.

RESULTS

Peramivir treatment reduced the mortality of mice infected with influenza virus and S. pneumoniae. The survival rate in the peramivir-treated group was significantly higher than that in the oseltamivir-treated group. Viral titers and proinflammatory cytokine responses in the peramivir-treated group were significantly lower than those in the oseltamivir-treated group until at 2days post viral infection. Bacterial titer was significantly lower in the peramivir-treated group than in the oseltamivir-treated group at 4days post viral infection.

CONCLUSION

These results demonstrated that peramivir inhibits viral replication, consequently leading to bacterial clearance and prevention of mortality during severe murine bacterial co-infection, which occurs during the period of viral shedding, with the efficacy of peramivir being superior to that of oseltamivir.

The safety of oseltamivir in pregnancy: an updated review of post-marketing data

PURPOSE

Influenza infection places pregnant women at greater risk of morbidity and hospitalization. The use of oseltamivir to treat influenza increased markedly in all population groups during the A/H1N1pdm09 pandemic, including pregnant women. Given this increase in exposure, a reassessment of the safety of oseltamivir in pregnancy was conducted.

METHODS

The Roche Global Safety Database was searched for all exposures to oseltamivir during pregnancy in the 13 years up to 30 April 2012.

RESULTS

Of the 2926 maternal exposures to oseltamivir retrieved from the Safety Database, pregnancy outcomes were known for 2128 women. Most exposures (>90%) were reported during or after the pandemic. The incidence of adverse pregnancy outcomes in exposed women was: spontaneous abortions, 2.9% (61/2128); therapeutic abortions, 1.8% (39/2128); and pre-term deliveries, 4.2% (84 of 2000 live births), values which are lower than background rates in the general population (women with or without influenza). Fetal outcomes were known in 1875 of the 2926 exposures. For the 81 reported birth defect cases, 11 occurred during the sensitive period for the respective defects. A review of these and other case reports of birth defects did not suggest that they resulted from oseltamivir exposure.

CONCLUSIONS

The data reviewed in this article reinforce the findings of a previous review, suggesting that oseltamivir is unlikely to cause adverse pregnancy or fetal outcomes.

Efficacy of Lianhuaqingwen capsule compared with oseltamivir for influenza A virus infection: a meta-analysis of randomized, controlled trials

In this meta-analysis, the authors review the results of studies on the efficacy of lianhuaqingwen capsule (LHQW-C) compared with oseltamivir in treating influenza A virus infection. The authors searched PubMed, Embase, Wanfang Data, and the China National Knowledge Infrastructure (CNKI) from the date of inception until December 31, 2012. The Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Database of Systematic Reviews (CDSR) were also searched. Five randomized, controlled trials were finally included and analyzed in this review. Compared with individuals treated with oseltamivir, this metaanalysis showed that participants treated with LHQW-C had a shorter duration of (1) fever, weighted mean difference (WMD) = -4.65 (95% CI, -8.91 to -0.38; P = .030); (2) cough, WMD = -9.79 (95% CI, -14.61 to -4.97; P < .0001); (3) sore throat, WMD = -13.01 (95% CI, -21.76 to -4.27; P = .004); and (4) body ache, WMD = -16.68 (95% CI, -32.33 to -1.03; P = .040). The review also found that the efficacy of the 2 treatments on viral shedding was similar with WMD = -0.24 (95% CI, -4.79 to 4.31; P = .920). The authors conclude that LHQW-C was superior to oseltamivir in improving the symptoms of influenza A virus infection.

Influenza and oseltamivir phosphate (Tamiflu) in infants: what you need to know

Influenza is a highly contagious virus that causes an average of 20,000 hospitalizations a year in children under five years of age. As of March 30, 2013, the 2012-2013 flu season had seen 111 pediatric deaths, with 21 deaths in the 0- to 23-month-old range. Rates of influenza-associated hospitalization are substantially higher among infants and young children than among older children, and those under six months old are at the highest risk. Research shows that influenza vaccine is not as effective in children two years of age relative to adults, and the vaccine is not approved in infants younger than six months. Thus, preventing influenza and proper treatment are important for keeping this high-risk group safe from complications. With infants being highest at risk for complications and the extrapolation of efficacy and safety from the older population, the U.S. Food and Drug Administration (FDA) recently approved the use of the antiviral oseltamivir phosphate (Tamiflu) for treatment of uncomplicated influenza in patients two weeks and older. This young population is susceptible to the benefits as well as the risks of the drug. Health care providers must be aware of dosing, adverse reactions, and monitoring parameters to better treat and educate their patients.

Pharmacokinetics of orally administered oseltamivir in healthy obese and nonobese Thai subjects

Oseltamivir is the most widely used anti-influenza drug. In the 2009 H1N1 pandemic, in which the influenza viruses were oseltamivir sensitive, obesity was identified as a risk factor for severe disease and unfavorable outcomes. The aim of this study was to investigate the pharmacokinetic properties of oseltamivir and its active metabolite, oseltamivir carboxylate, in obese and nonobese healthy subjects. A single-dose, randomized, two-sequence crossover study was conducted in 12 obese and 12 nonobese healthy Thai volunteers. Each volunteer was given 75 mg and 150 mg oseltamivir orally with an intervening washout period of more than 3 days. The pharmacokinetic properties of oseltamivir and oseltamivir carboxylate were evaluated using a noncompartmental approach. The median (range) body mass indexes (BMIs) for obese subjects were 33.8 kg/m(2) (30.8 to 43.2) and 22.2 (18.8 to 24.2) for nonobese subjects. The pharmacokinetic parameters of oseltamivir carboxylate, the active metabolite of oseltamivir, were not significantly different between obese and nonobese subjects for both 75-mg and 150-mg doses. Both doses were well tolerated. Despite the lower dose per kilogram body weight in obese subjects, there was no significant difference in the exposure of oseltamivir carboxylate between the obese and nonobese groups. Standard dosing is appropriate for obese subjects. (The study was registered at ClinicalTrials.gov under registration no. NCT 01049763.).

[The arsenolysis reaction in the biotechnological method of synthesis of the ribavirin. Inhibition of reproduction of influenza A virus with the combination of ribavirin and ozeltamivir in experiments in vitro and in vivo]

Improved biotechnological method of receiving the antiviral drug ribavirin by the reaction of transglycosilation by addition of catalytic amounts of sodium arsenate in the reaction mixture. Such approach allows to hydrolyze the amount of the excess natural nucleoside donor--ribose and, as a consequence, to simplify the composition of the reaction mixture and the process of separation of ribavirin. The effect of ribavirin and ozeltamivir carboxylate and their combination on the reproduction of the virus of the influenza A in cell culture and in experiments on laboratory animals (mouse Balb/C). The greatest anti-influenza effect is observed when using a combination of drugs, as compared to each of them taken separately.

Resistance mutation R292K is induced in influenza A(H6N2) virus by exposure of infected mallards to low levels of oseltamivir

Resistance to neuraminidase inhibitors (NAIs) is problematic as these drugs constitute the major treatment option for severe influenza. Extensive use of the NAI oseltamivir (Tamiflu®) results in up to 865 ng/L of its active metabolite oseltamivir carboxylate (OC) in river water. There one of the natural reservoirs of influenza A, dabbling ducks, can be exposed. We previously demonstrated that an influenza A(H1N1) virus in mallards (Anas platyrhynchos) exposed to 1 µg/L of OC developed oseltamivir resistance through the mutation H274Y (N2-numbering). In this study, we assessed the resistance development in an A(H6N2) virus, which belongs to the phylogenetic N2 group of neuraminidases with distinct functional and resistance characteristics. Mallards were infected with A(H6N2) while exposed to 120 ng/L, 1.2 µg/L or 12 µg/L of OC in their sole water source. After 4 days with 12 µg/L of OC exposure, the resistance mutation R292K emerged and then persisted. Drug sensitivity was decreased ≈13,000-fold for OC and ≈7.8-fold for zanamivir. Viral shedding was similar when comparing R292K and wild-type virus indicating sustained replication and transmission. Reduced neuraminidase activity and decrease in recovered virus after propagation in embryonated hen eggs was observed in R292K viruses. The initial, but not the later R292K isolates reverted to wild-type during egg-propagation, suggesting a stabilization of the mutation, possibly through additional mutations in the neuraminidase (D113N or D141N) or hemagglutinin (E216K). Our results indicate a risk for OC resistance development also in a N2 group influenza virus and that exposure to one NAI can result in a decreased sensitivity to other NAIs as well. If established in influenza viruses circulating among wild birds, the resistance could spread to humans via re-assortment or direct transmission. This could potentially cause an oseltamivir-resistant pandemic; a serious health concern as preparedness plans rely heavily on oseltamivir before vaccines can be mass-produced.

Low Dose Oral Combination Chemoprophylaxis with Oseltamivir and Amantadine for Influenza a Virus Infections in Mice

In the present study, the effect of combining anti-influenza drugs active at different steps of the influenza virus replication cycle, oseltamivir as a neuraminidase (NA) inhibitor and amantadine targeting M2 protein, was investigated in vivo by oral administration in a mouse model of aerosol influenza virus infection and in vitro in MDCK cells. In mice, doses of oseltamivir and amantadine providing 50-60% survival against A/Hongkong/1/68 (H3N2) or A/PR/8/34 (H1N1) were capable of conferring complete protection when used simultaneously, suggesting that increased inhibition of influenza virus replication by combining oseltamivir and amantadine in vitro translates into protection from lethal infection of mice. The combination of amantadine with oseltamivir required 15-fold less oseltamivir than monotherapy to confer complete protection against lethal aerosol influenza virus infection. Remarkably, amantadine-based combination chemoprophylaxis was even effective against amantadine-resistant A/PR/8/34 influenza virus. Thus, combination chemotherapy may be more efficacious than monotherapy against newly emerging Influenza A subtypes.

South East Asia Infectious Disease Clinical Research Network. Effect of double dose oseltamivir on clinical and virological outcomes in children and adults admitted to hospital with severe influenza: double blind randomised controlled trial

OBJECTIVE

To investigate the validity of recommendations in treatment guidelines to use higher than approved doses of oseltamivir in patients with severe influenza.

DESIGN

Double blind randomised trial.

SETTING

Thirteen hospitals in Indonesia, Singapore, Thailand, and Vietnam.

PARTICIPANTS

Patients aged ≥ 1 year admitted to hospital with confirmed severe influenza.

INTERVENTIONS

Oral oseltamivir at double dose (150 mg twice a day/paediatric equivalent) versus standard dose (75 mg twice a day/paediatric equivalent).

MAIN OUTCOME MEASURE

Viral status according to reverse transcriptase polymerase chain reaction (RT-PCR) for influenza RNA in nasal and throat swabs on day five.

RESULTS

Of 326 patients (including 246 (75.5%) children aged <15), 165 and 161 were randomised to double or standard dose oseltamivir, respectively. Of these, 260 (79.8%) were infected with influenza virus A (133 (40.8%) with A/H3N2, 72 (22.1%) with A/H1N1-pdm09, 38 (11.7%) with seasonal A/H1N1, 17 (5.2%) with A/H5N1) and 53 (16.2%) with influenza virus B. A further 3.9% (13) were false positive by rapid antigen test (negative by RT-PCR and no rise in convalescent haemagglutination inhibition titers). Similar proportions of patients were negative for RT-PCR on day five of treatment: 115/159 (72.3%, 95% confidence interval 64.9% to 78.7%) double dose recipients versus 105/154 (68.2%, 60.5% to 75.0%) standard dose recipients; difference 4.2% (-5.9 to 14.2); P=0.42. No differences were found in clearance of virus in subgroup analyses by virus type/subtype, age, and duration of illness before randomisation. Mortality was similar: 12/165 (7.3%, 4.2% to 12.3%) in double dose recipients versus 9/161 (5.6%, 3.0% to 10.3%) in standard dose recipients. No differences were found between double and standard dose arms in median days on supplemental oxygen (3 (interquartile range 2-5) v 3.5 (2-7)), in intensive care (4.5 (3-6) v 5 (2-11), and on mechanical ventilation (2.5 (1-16) v 8 (1-16)), respectively. No important differences in tolerability were found.

CONCLUSIONS

There were no virological or clinical advantages with double dose oseltamivir compared with standard dose in patients with severe influenza admitted to hospital.

REGISTRATION

Clinical Trials NCT00298233.

Prolonged influenza virus shedding and emergence of antiviral resistance in immunocompromised patients and ferrets

Immunocompromised individuals tend to suffer from influenza longer with more serious complications than otherwise healthy patients. Little is known about the impact of prolonged infection and the efficacy of antiviral therapy in these patients. Among all 189 influenza A virus infected immunocompromised patients admitted to ErasmusMC, 71 were hospitalized, since the start of the 2009 H1N1 pandemic. We identified 11 (15%) cases with prolonged 2009 pandemic virus replication (longer than 14 days), despite antiviral therapy. In 5 out of these 11 (45%) cases oseltamivir resistant H275Y viruses emerged. Given the inherent difficulties in studying antiviral efficacy in immunocompromised patients, we have infected immunocompromised ferrets with either wild-type, or oseltamivir-resistant (H275Y) 2009 pandemic virus. All ferrets showed prolonged virus shedding. In wild-type virus infected animals treated with oseltamivir, H275Y resistant variants emerged within a week after infection. Unexpectedly, oseltamivir therapy still proved to be partially protective in animals infected with resistant virus. Immunocompromised ferrets offer an attractive alternative to study efficacy of novel antiviral therapies.

Immunocompromised patients, such as transplant recipients on immune suppressive therapy, are a substantial and gradually expanding patient group. Upon influenza virus infection, these patients clear the virus less efficiently and are more likely to develop severe pneumonia than immunocompetent individuals. Existing antiviral strategies are far from satisfactory for this patient group, as they show limited effectiveness with frequent emergence of antiviral resistance. For ethical and practical reasons antiviral efficacy studies are hard to conduct in these patients. Therefore, we developed an immunocompromised ferret, mimicking an immune suppressive regimen used for solid organ transplant recipients. Upon infection with 2009 pandemic influenza A/H1N1 virus these animals, like immunocompromised patients, develop severe respiratory disease with prolonged virus excretion. Interestingly, all immunocompromised ferrets on oseltamivir therapy excreted oseltamivir resistant viruses (H275Y) within one week after start of treatment. Furthermore, high dose oseltamivir therapy still proved to be partially effective against these oseltamivir resistant viruses. These immunocompromised ferrets provide a useful tool in the development of novel antiviral approaches for immunocompromised patients suffering from influenza.

Anti-influenza A virus characteristics of a fucoidan from sporophyll of Undaria pinnatifida in mice with normal and compromised immunity

Undaria pinnatifida, an edible brown alga, contains fucoidan (FuC), a sulfated polysaccharide, that inhibited the in vitro replication of influenza A virus, and stimulated both innate and adaptive immune defense functions in virus-infected mice. In the present study, the effects of oral administration of FuC were evaluated on influenza virus infection in immunocompetent and immunocompromised mice, where the efficacy of FuC was demonstrated in reducing viral replication, decreasing weight loss and mortality, and prolonging survival. Oral FuC resulted in increased neutralizing antibody production in the mucosa and blood. In contrast, while suppressing virus yields in mice more markedly than FuC, oseltamivir significantly reduced the neutralizing antibody titers in both the mucosa and blood. In immunocompromised mice, drug-resistant viruses frequently recovered after oseltamivir treatment; no resistant viruses were isolated from FuC-treated mice. FuC could be a candidate for the development of new therapeutic options including its combination with neuraminidase inhibitors such as oseltamivir.

Oseltamivir and inhaled zanamivir as influenza prophylaxis in Thai health workers: a randomized, double-blind, placebo-controlled safety trial over 16 weeks

OBJECTIVES

Long-term chemoprophylaxis using neuraminidase inhibitors may be needed during influenza epidemics but safety data are limited to several weeks. We sought to assess the tolerability of oseltamivir and zanamivir as primary prophylaxis over 16 weeks.

METHODS

We conducted a parallel group, double blind, 2 (active drug) :1 (placebo) randomized trial of oral oseltamivir/placebo or inhaled zanamivir/placebo over 16 weeks in healthy, Thai hospital professionals at two Bangkok hospitals. The primary endpoint was study withdrawal due to drug-related (possibly, probably, definitely) serious or adverse events (AEs) graded ≥ 2.

RESULTS

Recruited subjects numbered 129 oseltamivir/65 placebo and 131 zanamivir/65 placebo. A total of 102 grade ≥ 2 AEs were reported or detected in 69 subjects: 23/129 (17.8%) versus 15/65 (23.1%) (P=0.26), and 23/131 (17.6%) versus 8/65 (12.3%) (P=0.28). Intercurrent infections/fevers [26/102 (25.5%)], abnormal biochemistry [25/102 (24.5%)] and gastrointestinal symptoms [18/102 (17.6%)] were the most frequently reported AEs. There were no drug-related study withdrawals. Eight serious AEs were all due to intercurrent illnesses. Laboratory, lung function and ECG parameters were similar between drugs and placebos.

CONCLUSIONS

Oseltamivir and zanamivir were well tolerated in healthy hospital professionals. Both drugs can be recommended for primary influenza prophylaxis for up to 16 weeks.

Oseltamivir in neonates, infants and young children: a focus on clinical pharmacology

Influenza is a cause of significant morbidity and mortality in young children. It is associated with high annual attack rates as well as being responsible for frequent outpatient visits and hospitalisations. Children aged <2 years are at the highest risk for serious illness or death during the influenza season. The neuraminidase inhibitor oseltamivir has been proven to reduce the duration and severity of illness when treatment is commenced within 48 hours of symptom onset. The H1N1 pandemic of 2009 prompted temporary emergency authorisation of oseltamivir use in infants aged <1 year in the USA. In December 2012, Food and Drug Administration (FDA) reinstated approval of oseltamivir to treat children younger than 1 year old including neonates who have shown symptoms of influenza for less than 48 hours. Current data on the use of oseltamivir in neonates and infants are limited. In this review, we evaluated accumulated data on oseltamivir use in newborns, infants and young children with a special focus on pharmacokinetics, efficacy and safety.

[Efficacy of anti-neuraminidase drugs application during and after an influenza pandemic]

The emergent 2009 A(H1N1) pandemic brought into acute focus the problem of choosing the most effective anti-influenza drugs for successive influenza infection spreading control. Oseltamivir and zanamivir, influenza virus neuraminidase inhibitors (NAIs), were recommended by the WHO experts for the treatment and prevention of influenza, including that caused by pandemic strains. A major concern regarding the use of specific antiviral compounds is the emergence of the drug-resistant strains. Oseltamivir carboxylate and zanamivir IC50 values were equal to 0.3-5.2 microM for the most of A(H1N1)pdm09 pandemic strains and 1.6-8.6 microM for the strains of influenza B virus in cell-based ELISA assay (2009-2010 season). All the studied strains of influenza A(H1N1 ) pdm09 (151) and B (22) viruses were sensitive to NAIs (2009-2011 seasons). For the first time in Russia oseltamivir-resistant A(H1N1) pdm09 influenza virus was isolated from the patient on the 5th day of a treatment course of this drug.

Effect of fever on hospital presentation, diagnosis, and treatment in patients with H1N1/09 influenza

OBJECTIVE

Fever is typically considered part of the influenza-like illness in hemagglutinin type 1 and neuraminidase type 1 (H1N1/09) influenza. We assessed the proportion of patients that did not have fever as part of their illness prior to hospital presentation. We assessed the role of fever on the delay in hospital presentation, diagnosis, and treatment of these patients.

METHODS

We performed a retrospective analysis of all hospitalized adult patients with laboratory-confirmed pandemic H1N1/09 at a tertiary care center in the United States from June 1 to December 31, 2009.

RESULTS

Fifty-six of 135 study patients (42%) had no fever; 31 (23%) required intensive care unit (ICU) admission, and 9 (7%) died. Those without fever had higher Charlson index (P = 0.01), significantly longer time to hospital presentation (median 4 vs 2 days, P < 0.001), longer time to treatment since the onset of illness (median 5 vs 2 days, P = 0.001), and were more frequently in an ICU (P = 0.01). After adjustment for age (<40 vs ≥40) and Charlson index (0, 1-2, ≥3), patients without fever had significantly increased likelihood of late hospital presentation (>2 days from the onset of illness) (P = 0.001) and also had increased likelihood of ICU stay (P = 0.05).

CONCLUSIONS

Forty-two percent of patients with laboratory-confirmed H1N1/09 did not have fever as part of their illness prior to hospital presentation. Patients without fever had delayed presentation to the hospital and thus experienced delayed treatment.

[Compliance and safety of oseltamivir treatment in children and infants less than one year of age]

BACKGROUND

Data regarding the compliance and safety of oseltamivir in infants < 1-year-old are limited.

AIM

To compare the rates of adverse effects and compliance with oseltamivir treatment among hospitalized children aged < 1-year-old with suspected influenza and older children.

METHODS

A telephone follow-up was carried out with parents of children admitted to hospital during the 2009-influenza pandemic within a week after their discharge, and their medical records were reviewed.

RESULTS

A total of 89 children were included (median age was 1.3 years old); 38.2% were < 1-year-old. Only 9% were diagnosed with pH1N1 influenza. The mean duration of therapy was 3 days. Difficulty in the administration of oseltamivir was reported in 52.8% of the children. Adverse effects were reported in 53.9% of the children. The most common were vomiting and/or diarrhea (32.6%) followed by restlessness (31.8%), and rash (6.7%). Treatment of only one child was discontinued due to a possible adverse event. The rates of adverse effects and difficulties in oseltamivir administration were similar among infants < 1-yr-old and older children.

CONCLUSIONS

The compliance and safety of oseltamivir therapy were similar among infants < 1-yr-old and older children. Difficulties in oseltamivir administrating and/or possible adverse effects have rarely influenced compliance. Liberal treatment with oseltamivir has led to prominent overuse of the medication.

Treatment of oseltamivir-resistant influenza A (H1N1) virus infections in mice with antiviral agents

Influenza A/Mississippi/03/2001 (H1N1) and A/Hong Kong/2369/2009 (H1N1) viruses containing the neuraminidase gene mutation H275Y (conferring resistance to oseltamivir) were adapted to mice and evaluated for suitability as models for lethal infection and antiviral treatment. The viral neuraminidases were resistant to peramivir and oseltamivir carboxylate but sensitive to zanamivir. Similar pattern of antiviral activity were seen in MDCK cell assays. Lethal infections were achieved in mice with the two viruses. Oral oseltamivir at 100 and 300mg/kg/day bid for 5day starting at -2h gave 30% and 60% protection from death, respectively, due to the A/Mississippi/03/2001 infection. Intraperitoneal treatments with zanamivir at 30 and 100mg/kg/day starting at -2h gave 60% and 90% protection, respectively. Neither compound at <300mg/kg/day protected mice when treatments began at +24h. Amantadine was effective at 10, 30, and 100mg/kg/day, rimantadine was protective at 10 and 30mg/kg/day (highest dose tested), and ribavirin was active at 30 and 75mg/kg/day, with survival ranging from 60-100% for oral treatments initiated at -2h. For treatments begun at +24h, amantadine was protective at 30 and 100mg/kg/day, rimantadine showed efficacy at 10 and 30mg/kg/day, and ribavirin was active at 75mg/kg/day, with 60-100% survival per group. In the A/Hong Kong/2369/2009 infection, oral oseltamivir at 100 and 300mg/kg/day starting at -2h gave 50% and 70% protection from death, respectively. These infection models will be useful to study newly discovered anti-influenza virus agents and to evaluate compounds in combination.

[The specific features of the cocirculation of influenza viruses in the 2010-2011 postpandemic period according to the results of activities of the D. I. Ivanovsky Research Institute of Virology, Ministry of Health and Social Development of Russia]

The paper gives the results of monitoring the circulation of influenza viruses in the 2010-2011 season, that covers the second year of circulation of pandemic A(H1N1)v virus strains, and their interaction with seasonal A (H3N2) and B strains. Unlike the previous season, the beginning of an increase in morbidity was recorded in January 2011; its peak in the most of contiguous areas was noted at 5-7 weeks of 2011, with its further decline to threshold levels at week 11 of 2011. Preschool and school children were most involved in the epidemic process. Three influenza virus strains (A(H1N1)v, A(H3N2), and B) were found to circulate. Differences were found in the level of participation of the isolated strains in individual areas of the Russian Federation. Detailed typing of the isolated strains determined the compliance of the vast majority of them with vaccine viruses. The pandemic influenza A(H1N1)v virus strains retained their susceptibility to oseltamivir and were resistant to rimantadine. The participation of non-influenza acute respiratory viral infection pathogens was estimated as follows: 11.9% for parainfluenza viruses, 5.9% for adenoviruses, and 3.5% for PC viruses, and 0.7% for pneumonia Mycoplasma, which was comparable with the previous epidemic seasons.

[Clinical efficiency in children treated with intravenous drip infusion of peramivir]

The clinical effect of peramivir was examined retrospectively in 30 children aged 23 days to 8 years; they had been treated with peramivir at our hospital within 48 hours after the onset of influenza from November 2010 to April 2011. Intravenous dripping of peramivir at a dose of 10 mg/kg was performed only once for 15 to 30 minutes. To examine the clinical effect of peramivir, the time from dosing to defervescence (body temperature <37.5 degrees C) was evaluated. To compare the clinical effects of peramivir and oseltamivir, the time required for the defervescence was evaluated in a similar manner in 30 children aged 7 months to 8 years who had been treated for influenza with oseltamivir at a dose of 4 mg/kg/day. The influenza type was type A (n=25) and type B (n=5) in the peramivir group and type A (n=26) and type B (n=4) in the oseltamivir group. In the peramivir group, 5 (16.7%), 16 (53.3%), and 24 (80.0%) patients achieved defervescence within 6, 12, and 24 hours, respectively. In the oseltamivir group, 3 (10.0%) and 6 (20.0%) patients had defervescence within 12 and 24 hours, respectively. The difference between these groups was statistically significant (p<0.05). An increase in the levels of AST and ALT was observed as an adverse reaction in 1 patient. Thus, peramivir was determined to be effective to influenza in children.

[Efficacy of combined administration of ridostin and oseltamivir (tamiflu) for therapy and prophylaxis of experimental infection induced by influenza virus A (H5N1) in mice]

AIM

Study of possibility of treatment-prophylaxis effect increase during combined administration of ridostin and tamiflu in experiments in mice infected with highly pathogenic influenza virus strain A/chicken/Kurgan/05/2005 (H5N1).

MATERIALS AND METHODS

Balb/c line mice infected intranasally with influenza virus at 100 and 10 LD50 doses received ridostin and tamiflu as monopreparation or the combined variant before or after the infection. The mice were observed for 16 days, lethality rate, protection coefficient and average life span were evaluated. Virus concentration in lungs was determined by using titration in MDCK cell line.

RESULTS

Combined administration ofridostin and tamiflu after the infection increased survivability of the animals when compared with the control group, and reduced influenza virus concentration in lungs.

CONCLUSION

Treatment effect during combined administration of ridostin and tamiflu after influenza virus infection increased.