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The Cochrane Database of Systematic... Apr 2014Neuraminidase inhibitors (NIs) are stockpiled and recommended by public health agencies for treating and preventing seasonal and pandemic influenza. They are used... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Neuraminidase inhibitors (NIs) are stockpiled and recommended by public health agencies for treating and preventing seasonal and pandemic influenza. They are used clinically worldwide.
OBJECTIVES
To describe the potential benefits and harms of NIs for influenza in all age groups by reviewing all clinical study reports of published and unpublished randomised, placebo-controlled trials and regulatory comments.
SEARCH METHODS
We searched trial registries, electronic databases (to 22 July 2013) and regulatory archives, and corresponded with manufacturers to identify all trials. We also requested clinical study reports. We focused on the primary data sources of manufacturers but we checked that there were no published randomised controlled trials (RCTs) from non-manufacturer sources by running electronic searches in the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE (Ovid), EMBASE, Embase.com, PubMed (not MEDLINE), the Database of Reviews of Effects, the NHS Economic Evaluation Database and the Health Economic Evaluations Database.
SELECTION CRITERIA
Randomised, placebo-controlled trials on adults and children with confirmed or suspected exposure to naturally occurring influenza.
DATA COLLECTION AND ANALYSIS
We extracted clinical study reports and assessed risk of bias using purpose-built instruments. We analysed the effects of zanamivir and oseltamivir on time to first alleviation of symptoms, influenza outcomes, complications, hospitalisations and adverse events in the intention-to-treat (ITT) population. All trials were sponsored by the manufacturers.
MAIN RESULTS
We obtained 107 clinical study reports from the European Medicines Agency (EMA), GlaxoSmithKline and Roche. We accessed comments by the US Food and Drug Administration (FDA), EMA and Japanese regulator. We included 53 trials in Stage 1 (a judgement of appropriate study design) and 46 in Stage 2 (formal analysis), including 20 oseltamivir (9623 participants) and 26 zanamivir trials (14,628 participants). Inadequate reporting put most of the zanamivir studies and half of the oseltamivir studies at a high risk of selection bias. There were inadequate measures in place to protect 11 studies of oseltamivir from performance bias due to non-identical presentation of placebo. Attrition bias was high across the oseltamivir studies and there was also evidence of selective reporting for both the zanamivir and oseltamivir studies. The placebo interventions in both sets of trials may have contained active substances. Time to first symptom alleviation. For the treatment of adults, oseltamivir reduced the time to first alleviation of symptoms by 16.8 hours (95% confidence interval (CI) 8.4 to 25.1 hours, P < 0.0001). This represents a reduction in the time to first alleviation of symptoms from 7 to 6.3 days. There was no effect in asthmatic children, but in otherwise healthy children there was (reduction by a mean difference of 29 hours, 95% CI 12 to 47 hours, P = 0.001). Zanamivir reduced the time to first alleviation of symptoms in adults by 0.60 days (95% CI 0.39 to 0.81 days, P < 0.00001), equating to a reduction in the mean duration of symptoms from 6.6 to 6.0 days. The effect in children was not significant. In subgroup analysis we found no evidence of a difference in treatment effect for zanamivir on time to first alleviation of symptoms in adults in the influenza-infected and non-influenza-infected subgroups (P = 0.53). Hospitalisations. Treatment of adults with oseltamivir had no significant effect on hospitalisations: risk difference (RD) 0.15% (95% CI -0.78 to 0.91). There was also no significant effect in children or in prophylaxis. Zanamivir hospitalisation data were unreported. Serious influenza complications or those leading to study withdrawal. In adult treatment trials, oseltamivir did not significantly reduce those complications classified as serious or those which led to study withdrawal (RD 0.07%, 95% CI -0.78 to 0.44), nor in child treatment trials; neither did zanamivir in the treatment of adults or in prophylaxis. There were insufficient events to compare this outcome for oseltamivir in prophylaxis or zanamivir in the treatment of children. Pneumonia. Oseltamivir significantly reduced self reported, investigator-mediated, unverified pneumonia (RD 1.00%, 95% CI 0.22 to 1.49); number needed to treat to benefit (NNTB) = 100 (95% CI 67 to 451) in the treated population. The effect was not significant in the five trials that used a more detailed diagnostic form for pneumonia. There were no definitions of pneumonia (or other complications) in any trial. No oseltamivir treatment studies reported effects on radiologically confirmed pneumonia. There was no significant effect on unverified pneumonia in children. There was no significant effect of zanamivir on either self reported or radiologically confirmed pneumonia. In prophylaxis, zanamivir significantly reduced the risk of self reported, investigator-mediated, unverified pneumonia in adults (RD 0.32%, 95% CI 0.09 to 0.41); NNTB = 311 (95% CI 244 to 1086), but not oseltamivir. Bronchitis, sinusitis and otitis media. Zanamivir significantly reduced the risk of bronchitis in adult treatment trials (RD 1.80%, 95% CI 0.65 to 2.80); NNTB = 56 (36 to 155), but not oseltamivir. Neither NI significantly reduced the risk of otitis media and sinusitis in both adults and children. Harms of treatment. Oseltamivir in the treatment of adults increased the risk of nausea (RD 3.66%, 95% CI 0.90 to 7.39); number needed to treat to harm (NNTH) = 28 (95% CI 14 to 112) and vomiting (RD 4.56%, 95% CI 2.39 to 7.58); NNTH = 22 (14 to 42). The proportion of participants with four-fold increases in antibody titre was significantly lower in the treated group compared to the control group (RR 0.92, 95% CI 0.86 to 0.97, I(2) statistic = 0%) (5% absolute difference between arms). Oseltamivir significantly decreased the risk of diarrhoea (RD 2.33%, 95% CI 0.14 to 3.81); NNTB = 43 (95% CI 27 to 709) and cardiac events (RD 0.68%, 95% CI 0.04 to 1.0); NNTB = 148 (101 to 2509) compared to placebo during the on-treatment period. There was a dose-response effect on psychiatric events in the two oseltamivir "pivotal" treatment trials, WV15670 and WV15671, at 150 mg (standard dose) and 300 mg daily (high dose) (P = 0.038). In the treatment of children, oseltamivir induced vomiting (RD 5.34%, 95% CI 1.75 to 10.29); NNTH = 19 (95% CI 10 to 57). There was a significantly lower proportion of children on oseltamivir with a four-fold increase in antibodies (RR 0.90, 95% CI 0.80 to 1.00, I(2) = 0%). Prophylaxis. In prophylaxis trials, oseltamivir and zanamivir reduced the risk of symptomatic influenza in individuals (oseltamivir: RD 3.05% (95% CI 1.83 to 3.88); NNTB = 33 (26 to 55); zanamivir: RD 1.98% (95% CI 0.98 to 2.54); NNTB = 51 (40 to 103)) and in households (oseltamivir: RD 13.6% (95% CI 9.52 to 15.47); NNTB = 7 (6 to 11); zanamivir: RD 14.84% (95% CI 12.18 to 16.55); NNTB = 7 (7 to 9)). There was no significant effect on asymptomatic influenza (oseltamivir: RR 1.14 (95% CI 0.39 to 3.33); zanamivir: RR 0.97 (95% CI 0.76 to 1.24)). Non-influenza, influenza-like illness could not be assessed due to data not being fully reported. In oseltamivir prophylaxis studies, psychiatric adverse events were increased in the combined on- and off-treatment periods (RD 1.06%, 95% CI 0.07 to 2.76); NNTH = 94 (95% CI 36 to 1538) in the study treatment population. Oseltamivir increased the risk of headaches whilst on treatment (RD 3.15%, 95% CI 0.88 to 5.78); NNTH = 32 (95% CI 18 to 115), renal events whilst on treatment (RD 0.67%, 95% CI -2.93 to 0.01); NNTH = 150 (NNTH 35 to NNTB > 1000) and nausea whilst on treatment (RD 4.15%, 95% CI 0.86 to 9.51); NNTH = 25 (95% CI 11 to 116).
AUTHORS' CONCLUSIONS
Oseltamivir and zanamivir have small, non-specific effects on reducing the time to alleviation of influenza symptoms in adults, but not in asthmatic children. Using either drug as prophylaxis reduces the risk of developing symptomatic influenza. Treatment trials with oseltamivir or zanamivir do not settle the question of whether the complications of influenza (such as pneumonia) are reduced, because of a lack of diagnostic definitions. The use of oseltamivir increases the risk of adverse effects, such as nausea, vomiting, psychiatric effects and renal events in adults and vomiting in children. The lower bioavailability may explain the lower toxicity of zanamivir compared to oseltamivir. The balance between benefits and harms should be considered when making decisions about use of both NIs for either the prophylaxis or treatment of influenza. The influenza virus-specific mechanism of action proposed by the producers does not fit the clinical evidence.
Topics: Adult; Antiviral Agents; Child; Drug Evaluation; Enzyme Inhibitors; Europe; Health Status; Humans; Influenza, Human; Japan; Legislation, Drug; Neuraminidase; Oseltamivir; Pneumonia; Publication Bias; Randomized Controlled Trials as Topic; United Kingdom; United States; Zanamivir
PubMed: 24718923
DOI: 10.1002/14651858.CD008965.pub4 -
PLoS Neglected Tropical Diseases Jan 2022Thrombocytopenia, bleeding and plasma leakage are major complications of dengue. Activation of endogenous sialidases with desialylation of platelets and endothelial... (Randomized Controlled Trial)
Randomized Controlled Trial
Effect of oseltamivir phosphate versus placebo on platelet recovery and plasma leakage in adults with dengue and thrombocytopenia; a phase 2, multicenter, double-blind, randomized trial.
BACKGROUND
Thrombocytopenia, bleeding and plasma leakage are major complications of dengue. Activation of endogenous sialidases with desialylation of platelets and endothelial cells may underlie these complications. We aimed to assess the effects of the neuraminidase inhibitor oseltamivir on platelet recovery and plasma leakage in dengue.
METHODS
We performed a phase 2, double-blind, multicenter, randomized trial in adult dengue patients with thrombocytopenia (<70,000/μl) and a duration of illness ≤ 6 days. Oseltamivir phosphate 75mg BID or placebo were given for a maximum of five days. Primary outcomes were the time to platelet recovery (≥ 100,000/μl) or discharge from hospital and the course of measures of plasma leakage.
RESULTS
A total of 70 patients were enrolled; the primary outcome could be assessed in 64 patients (31 oseltamivir; 33 placebo). Time to platelet count ≥100,000/μl (n = 55) or discharge (n = 9) were similar in the oseltamivir and placebo group (3.0 days [95% confidence interval, 2.7 to 3.3] vs. 2.9 days [2.5 to 3.3], P = 0.055). The kinetics of platelet count and parameters of plasma leakage (gall bladder thickness, hematocrit, plasma albumin, syndecan-1) were also similar between the groups.
DISCUSSION
In this trial, adjunctive therapy with oseltamivir phosphate had no effect on platelet recovery or plasma leakage parameters.
TRIAL REGISTRATION
ISRCTN35227717.
Topics: Adolescent; Adult; Antiviral Agents; Blood Platelets; Dengue; Double-Blind Method; Female; Humans; Male; Oseltamivir; Young Adult
PubMed: 34995275
DOI: 10.1371/journal.pntd.0010051 -
The Journal of Antimicrobial... Apr 2010Influenza is a transmissible viral pathogen that continues to cause substantial morbidity and mortality. Oseltamivir is an orally administered antiviral medication that... (Review)
Review
Influenza is a transmissible viral pathogen that continues to cause substantial morbidity and mortality. Oseltamivir is an orally administered antiviral medication that selectively inhibits the influenza neuraminidase enzymes that are essential for viral replication. Treatment of infected children > or =1 year and adults of all ages may decrease the severity and duration of the symptoms of infection, while prophylactic dosing can prevent their onset. Oseltamivir is ingested in the form of a prodrug (oseltamivir phosphate) that is rapidly converted by hepatic esterases into the active metabolite, oseltamivir carboxylate. Oseltamivir carboxylate has high bioavailability and penetrates sites of infection at concentrations that are sufficient to inhibit viral replication. The pharmacokinetics of oseltamivir and oseltamivir carboxylate are dose proportional after repeated doses of up to 500 mg twice daily. This predictable profile means that oseltamivir is suitable for use in diverse patient populations, which may include young children and elderly patients, various ethnic groups and those with renal or hepatic impairment. As the potential for drug interactions is low, oseltamivir is also suitable for use in patients with co-morbid conditions who are likely to be receiving concomitant medications.
Topics: Administration, Oral; Antiviral Agents; Biological Availability; Drug Interactions; Humans; Influenza, Human; Oseltamivir; Prodrugs
PubMed: 20215135
DOI: 10.1093/jac/dkq015 -
Oncotarget Jun 2016Several of the growth factors and their receptor tyrosine kinases (RTK) such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF), fibroblast growth... (Review)
Review
Several of the growth factors and their receptor tyrosine kinases (RTK) such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), nerve growth factor (NGF) and insulin are promising candidate targets for cancer therapy. Indeed, tyrosine kinase inhibitors (TKI) have been developed to target these growth factors and their receptors, and have demonstrated dramatic initial responses in cancer therapy. Yet, most patients ultimately develop TKI drug resistance and relapse. It is essential in the clinical setting that the targeted therapies are to circumvent multistage tumorigenesis, including genetic mutations at the different growth factor receptors, tumor neovascularization, chemoresistance of tumors, immune-mediated tumorigenesis and the development of tissue invasion and metastasis. Here, we identify a novel receptor signaling platform linked to EGF, NGF, insulin and TOLL-like receptor (TLR) activations, all of which are known to play major roles in tumorigenesis. The importance of these findings signify an innovative and promising entirely new targeted therapy for cancer. The role of mammalian neuraminidase-1 (Neu1) in complex with matrix metalloproteinase-9 and G protein-coupled receptor tethered to RTKs and TLRs is identified as a major target in multistage tumorigenesis. Evidence exposing the link connecting growth factor-binding and immune-mediated tumorigenesis to this novel receptor-signaling paradigm will be reviewed in its current relationship to cancer.
Topics: Animals; Breast Neoplasms; Carcinogenesis; Cell Survival; Disease Progression; Drug Resistance, Neoplasm; Enzyme Activation; ErbB Receptors; Female; Humans; Macrophages; Matrix Metalloproteinase 9; Mice; Mutation; Neoplasm Metastasis; Neoplasms; Neuraminidase; Oseltamivir; Ovarian Neoplasms; Receptor Protein-Tyrosine Kinases; Signal Transduction
PubMed: 27029067
DOI: 10.18632/oncotarget.8396 -
Cancers Jul 2022Metastatic pancreatic cancer has an invariably fatal outcome, with an estimated median progression-free survival of approximately six months employing our best...
Repositioning of Old Drugs for Novel Cancer Therapies: Continuous Therapeutic Perfusion of Aspirin and Oseltamivir Phosphate with Gemcitabine Treatment Disables Tumor Progression, Chemoresistance, and Metastases.
Metastatic pancreatic cancer has an invariably fatal outcome, with an estimated median progression-free survival of approximately six months employing our best combination chemotherapeutic regimens. Once drug resistance develops, manifested by increased primary tumor size and new and growing metastases, patients often die rapidly from their disease. Emerging evidence indicates that chemotherapy may contribute to the development of drug resistance through the upregulation of epithelial-mesenchymal transition (EMT) pathways and subsequent cancer stem cell (CSC) enrichment. Neuraminidase-1 (Neu-1) regulates the activation of several receptor tyrosine kinases implicated in EMT induction, angiogenesis, and cellular proliferation. Here, continuous therapeutic targeting of Neu-1 using parenteral perfusion of oseltamivir phosphate (OP) and aspirin (ASA) with gemcitabine (GEM) treatment significantly disrupts tumor progression, critical compensatory signaling mechanisms, EMT program, CSC, and metastases in a preclinical mouse model of human pancreatic cancer. ASA- and OP-treated xenotumors significantly inhibited the metastatic potential when transferred into animals.
PubMed: 35892853
DOI: 10.3390/cancers14153595 -
Science Advances Jun 2023Viral infections continue to threaten human health. It remains a major challenge to efficiently inhibit viral infection while avoiding secondary injury. Here, we...
Viral infections continue to threaten human health. It remains a major challenge to efficiently inhibit viral infection while avoiding secondary injury. Here, we designed a multifunctional nanoplatform (termed as ODCM), prepared by oseltamivir phosphate (OP)-loaded polydopamine (PDA) nanoparticles camouflaged by the macrophage cell membrane (CM). OP can be efficiently loaded onto the PDA nanoparticles through the π-π stacking and hydrogen bonding interactions with a high drug-loading rate of 37.6%. In particular, the biomimetic nanoparticles can accumulate actively in the damaged lung model of viral infection. At the infection site, PDA nanoparticles can consume excess reactive oxygen species and be simultaneously oxidized and degraded to achieve controlled release of OP. This system exhibits enhanced delivery efficiency, inflammatory storm suppression, and viral replication inhibition. Therefore, the system exerts outstanding therapeutic effects while improving pulmonary edema and protecting lung injury in a mouse model of influenza A virus infection.
Topics: Humans; Animals; Mice; Antiviral Agents; Nanomedicine; Oseltamivir; Indoles
PubMed: 37315148
DOI: 10.1126/sciadv.adf4098 -
BMC Pharmacology & Toxicology Feb 2023The study was aimed at evaluating the bioequivalence and safety of oseltamivir phosphate for suspension, provided by Shenzhen Beimei Pharmaceutical Co. Ltd. and... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
The study was aimed at evaluating the bioequivalence and safety of oseltamivir phosphate for suspension, provided by Shenzhen Beimei Pharmaceutical Co. Ltd. and manufactured by Hetero Labs Limited, and the reference product TAMIFLU® in healthy Chinese subjects.
METHODS
A single-dose, randomized, two-phase, self-crossed model was adopted. Among 80 healthy subjects, 40 subjects in the fasting group and 40 subjects in the fed group. Subjects in the fasting group were randomized into two sequences according to the proportion of 1:1, each given 75 mg/12.5 mL of Oseltamivir Phosphate for Suspension or TAMIFLU®, and cross-administered after 7 days. Postprandial group is the same as fasting group.
RESULTS
The T of TAMIFLU® and Oseltamivir Phosphate for Suspension in the fasting group were 1.50 h and 1.25 h, which in the fed group were both 1.25 h. Geometrically adjusted mean ratios of the PK parameters of Oseltamivir Phosphate for Suspension along with TAMIFLU® under fasting and postprandial conditions were in the range of 80.00-125.00% at the 90% confidence interval (CI). The 90% CI of C, AUC, AUC for fasting group and postprandial group were (92.39,106.50), (94.26,100.67), (94.32,100.89) and (93.61,105.83),(95.64,100.19),(96.06,102.66). Among the subjects on medication, a total of 18 subjects reported 27 adverse events, all of which were treatment-emergent adverse events (TEAEs), six of these TEAEs were rated as grade 2 in severity and the rest were as grade 1. The number of TEAEs in the test product and the reference product were 14,13 respectively.
CONCLUSION
Two Oseltamivir phosphate for suspensions are safe and bioequivalent.
Topics: Humans; Oseltamivir; Therapeutic Equivalency; Suspensions; Cross-Over Studies; Area Under Curve; Fasting; Healthy Volunteers; Phosphates; Tablets
PubMed: 36810140
DOI: 10.1186/s40360-023-00646-1 -
BMJ (Clinical Research Ed.) Apr 2014To describe the potential benefits and harms of oseltamivir by reviewing all clinical study reports (or similar document when no clinical study report exists) of... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To describe the potential benefits and harms of oseltamivir by reviewing all clinical study reports (or similar document when no clinical study report exists) of randomised placebo controlled trials and regulatory comments ("regulatory information").
DESIGN
Systematic review of regulatory information.
DATA SOURCES
Clinical study reports, trial registries, electronic databases, regulatory archives, and correspondence with manufacturers.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Randomised placebo controlled trials on adults and children who had confirmed or suspected exposure to natural influenza.
MAIN OUTCOME MEASURES
Time to first alleviation of symptoms, influenza outcomes, complications, admissions to hospital, and adverse events in the intention to treat population.
RESULTS
From the European Medicines Agency and Roche, we obtained clinical study reports for 83 trials. We included 23 trials in stage 1 (reliability and completeness screen) and 20 in stage 2 (formal analysis). In treatment trials on adults, oseltamivir reduced the time to first alleviation of symptoms by 16.8 hours (95% confidence interval 8.4 to 25.1 hours, P<0.001). There was no effect in children with asthma, but there was an effect in otherwise healthy children (mean difference 29 hours, 95% confidence interval 12 to 47 hours, P=0.001). In treatment trials there was no difference in admissions to hospital in adults (risk difference 0.15%, 95% confidence interval -0.91% to 0.78%, P=0.84) and sparse data in children and for prophylaxis. In adult treatment trials, oseltamivir reduced investigator mediated unverified pneumonia (risk difference 1.00%, 0.22% to 1.49%; number needed to treat to benefit (NNTB) 100, 95% confidence interval 67 to 451). The effect was not statistically significant in the five trials that used a more detailed diagnostic form for "pneumonia," and no clinical study reports reported laboratory or diagnostic confirmation of "pneumonia." The effect on unverified pneumonia in children and for prophylaxis was not significant. There was no significant reduction in risk of unverified bronchitis, otitis media, sinusitis, or any complication classified as serious or that led to study withdrawal. 14 of 20 trials prompted participants to self report all secondary illnesses to an investigator. Oseltamivir in the treatment of adults increased the risk of nausea (risk difference 3.66%, 0.90% to 7.39%; number needed to treat to harm (NNTH) 28, 95% confidence interval 14 to 112) and vomiting (4.56%, 2.39% to 7.58%; 22, 14 to 42). In treatment of children, oseltamivir induced vomiting (5.34%, 1.75% to 10.29%; 19, 10 to 57). In prophylaxis trials, oseltamivir reduced symptomatic influenza in participants by 55% (3.05%, 1.83% to 3.88%; NNTB 33, 26 to 55) and households (13.6%, 9.52% to 15.47%; NNTB 7, 6 to 11) based on one study, but there was no significant effect on asymptomatic influenza and no evidence of a reduction in transmission. In prophylaxis studies, oseltamivir increased the risk of psychiatric adverse events during the combined "on-treatment" and "off-treatment" periods (risk difference 1.06%, 0.07% to 2.76%; NNTH 94, 36 to 1538) and there was a dose-response effect on psychiatric events in two "pivotal" treatment trials of oseltamivir, at 75 mg (standard dose) and 150 mg (high dose) twice daily (P=0.038). In prophylaxis studies, oseltamivir increased the risk of headaches on-treatment (risk difference 3.15%, 0.88% to 5.78%; NNTH 32, 18 to 115), renal events with treatment (0.67%, -0.01% to 2.93%), and nausea while receiving treatment (4.15%, 0.86% to 9.51%; NNTH 25, 11 to 116).
CONCLUSIONS
In prophylactic studies oseltamivir reduces the proportion of symptomatic influenza. In treatment studies it also modestly reduces the time to first alleviation of symptoms, but it causes nausea and vomiting and increases the risk of headaches and renal and psychiatric syndromes. The evidence of clinically significant effects on complications and viral transmission is limited because of rarity of such events and problems with study design. The trade-off between benefits and harms should be borne in mind when making decisions to use oseltamivir for treatment, prophylaxis, or stockpiling.
Topics: Adult; Age Factors; Antiviral Agents; Child; Headache; Humans; Influenza, Human; Kidney Diseases; Nausea; Oseltamivir; Randomized Controlled Trials as Topic; Treatment Outcome; Vomiting
PubMed: 24811411
DOI: 10.1136/bmj.g2545 -
ADMET & DMPK 2019Oseltamivir phosphate (OP, Tamiflu®) is a widely used prodrug for the treatment of influenza viral infections. Orally administered OP is rapidly hydrolyzed by the...
Oseltamivir phosphate (OP, Tamiflu®) is a widely used prodrug for the treatment of influenza viral infections. Orally administered OP is rapidly hydrolyzed by the carboxylesterases in animals to oseltamivir carboxylate (OC), a potent influenza virus neuraminidase inhibitor. The goals of this study were to develop and validate a physiologically-based pharmacokinetic (PBPK) model of OP/OC in rats and humans, and to predict the internal tissue doses for OP and OC in humans after receiving OP orally. To this end, a PBPK model of OP/OC was first developed in the rat, which was then scaled up to humans by replacing the physiological and biochemical parameters with human-specific values. The proposed PBPK model consisted of an OP and an OC sub-models each containing nine first-order, flow-limited tissue/organ compartments. OP metabolism to OC was assumed to carry out mainly by hepatic carboxylesterases although extra-hepatic metabolism also occurred especially in the plasma. The PBPK model was developed and validated by experimental data from our laboratories and from the literature. The proposed PBPK model accurately predicted the pharmacokinetic behavior of OP and OC in humans and rats after receiving a single or multiple doses of OP orally or an OC dose i.v. The PBPK model was used to predict the internal tissue doses of OP and OC in a hypothetical human after receiving the recommended dose of 75 mg/kg OP b.i.d. for 6 days. Steady-state OC concentrations in the plasma and major organs such as the lung and the brain were higher than the minimum in vitro IC50 reported for H1N1 influenza virus neuraminidase, confirming OP is an effective, anti-viral agent. OP side-effects in the gastrointestinal tract and brain of humans were explainable by the tissue doses found in these organs. The PBPK model provides a quantitative tool to evaluate the relationship between an externally applied dose of OP and the internal tissue doses in humans. As such the model can be used to adjust the dose regimens for adult patients in disease states e.g., renal failure and liver damage.
PubMed: 35350745
DOI: 10.5599/admet.628 -
Virology Jan 2013The cytokine storm is an aggressive immune response characterized by the recruitment of inflammatory leukocytes and exaggerated levels of cytokines and chemokines at the... (Review)
Review
The cytokine storm is an aggressive immune response characterized by the recruitment of inflammatory leukocytes and exaggerated levels of cytokines and chemokines at the site of infection. Here we review evidence that cytokine storm directly contributes to the morbidity and mortality resulting from influenza virus infection and that sphingosine-1-phosphate (S1P) receptor agonists can abort cytokine storms providing significant protection against pathogenic human influenza viral infections. In experiments using murine models and the human pathogenic 2009 influenza viruses, S1P1 receptor agonist alone reduced deaths from influenza virus by over 80% as compared to lesser protection (50%) offered by the antiviral neuraminidase inhibitor oseltamivir. Optimal protection of 96% was achieved by combined therapy with the S1P1 receptor agonist and oseltamivir. The functional mechanism of S1P receptor agonist(s) action and the predominant role played by pulmonary endothelial cells as amplifiers of cytokine storm during influenza infection are described.
Topics: Animals; Cytokines; Drug Synergism; Drug Therapy, Combination; Endothelial Cells; Enzyme Inhibitors; Humans; Influenza A Virus, H1N1 Subtype; Influenza, Human; Lung; Mice; Mycotoxins; Orthomyxoviridae Infections; Oseltamivir; Receptors, Lysosphingolipid; Survival Rate
PubMed: 23217619
DOI: 10.1016/j.virol.2012.09.039