Oseltamivir resistant strains. Medical search. Frequent questions

A/Shanghai/1/2013 with mixed R/K at residue 292 exhibited a phenotype that is sensitive to zanamivir and oseltamivir carboxylate by the enzyme-based NA inhibition assay. (flutrackers.com)
Neuraminidase inhibitors (NAIs), such as oseltamivir and zanamivir, are the medicines of choice against influenza A or B. Oseltamivir resistance can be conferred by a single point missense mutation from histidine to tyrosine at position 275 (H275Y) of the neuraminidase gene. (eurekaselect.com)
of further concern, strains demonstrating low level resistance to both oseltamivir and zanamivir have been reported. (eurekaselect.com)
Antiviral agents available for influenza treatment and/or prevention include neuraminidase inhibitors (oseltamivir, peramivir, zanamivir) and the cap-dependent endonuclease inhibitor (baloxavir marboxil). (medscape.com)
The Tamiflu-resistant H1N1 strains are sensitive to another drug, Relenza (zanamivir). (virology.ws)
Zanamivir and oseltamivir, which are prodrugs processed in vivo to their active form, can inhibit both IAV and IBV replication, reducing the duration time of virus release. (pharmacytimes.com)
IV peramivir is a reserved treatment option for those that cannot take oral oseltamivir or tolerate inhaled zanamivir. (hdrxservices.com)
No reason to abuse it, even though resistent strains do not seem to be resistant to zanamivir. (caymannewsservice.com)
Influenza viruses are treated with two classes of drugs: M2 blockers (adamantanes) and neuraminidase inhibitors (NAIs), including oseltamivir and zanamivir. (medicaldesignandoutsourcing.com)
These findings suggest that oseltamivir may not be the frontline drug of choice in hematology patients, and zanamivir may prove to be more beneficial," the study authors wrote. (medicaldesignandoutsourcing.com)
ABSTRACT We monitored phenotypic and genotypic susceptibility of influenza viruses circulating in Morocco during 2014-2015 to oseltamivir and zanamivir. (who.int)
The current therapeutic regimen for influenza A viruses is limited to two classes of drugs: the adamantanes (amantadine and rimantadine) and the neuraminidase inhibitors (oseltamivir and zanamivir). (distantreader.org)
Oseltamivir and zanamivir are antiviral neuraminidase inhibitors that are used for chemoprophylaxis and treatment of influenza A and B infection. (medscape.com)
Zanamivir and oseltamivir are members of a class of drugs termed neuraminidase inhibitors and are active against both influenza virus type A and type B. They are approved for both prophylaxis and treatment of influenza. (medscape.com)
The Cochrane Collaboration published an evidence review of Tamiflu (the antiviral drug oseltamivir) and Relenza (zanamivir) trials, reporting that Tamiflu shortens symptoms of influenza but other claims made for the drugs were not well supported by evidence from clinical study reports. (sciencemediacentre.org)

Oseltamivir resistance in seasonal influenza A/H1N1 strains rose markedly during the 2007-2008 season. (eurekaselect.com)
Furthermore, oseltamivir resistant (OsR) strains of pandemic influenza A/H1N1 2009 (influenza A(H1N1)pdm09) have been increasingly isolated, although the majority remain sensitive. (eurekaselect.com)
The authors cited antiviral resistance to other therapies as a threat, as evidenced by global circulation of oseltamivir-resistant seasonal influenza A (H1N1) viruses in 2008-2009, as well as community clusters of oseltamivir-resistant influenza A (H1N1) viruses. (medpagetoday.com)
As with other influenza strains, H1N1 flu can be expected to show signs of resistance to oseltamivir, and new treatments will be needed to respond to this and future pandemics. (tgen.org)
The WHO said it was investigating the extent of resistance worldwide to Tamiflu, known generically as oseltamivir, in some seasonal H1N1 flu viruses that have a mutation making them "highly resistant. (yourlawyer.com)
Â "The frequency of oseltamivir resistance in H1N1 viruses in the current influenza season is unexpected and the reason why a higher percentage of these viruses are resistant is currently unknown," the WHO said. (yourlawyer.com)
The study found that Pelargonium sidoides was effective against pandemic H1N1, oseltamivir-sensitive and -resistant seasonal H1N1, seasonal H3N2 and the laboratory H1N1 strain A/Puerto Rico/8/34. (drmichellecook.com)
Yesterday the New York Times ran an article on the resistance to Tamiflu of current influenza H1N1 strains circulating in the US. (virology.ws)
Most of the flu in the US now is caused by H1N1 strains. (virology.ws)
However, these H1N1 strains are sensitive to Rimantadine, so its use is a good alternative. (virology.ws)
15.6% for the A/H1N1 strain) during the 2005/2006 influenza season. (pharmacytimes.com)
Using it inappropriately is irresponsible as it increases the chance of the H1N1 flu virusbecoming resistant to the drug. (caymannewsservice.com)
The results demonstrated that N30 inhibited the replication of H1N1, H3N2, influenza B viruses, including oseltamivir and amantadine resistant strains in vitro. (biomedcentral.com)
The study analyzed 28 seasonal H1N1 viruses with dual resistance from 2008 to 2010 from five countries, revealing that additional antiviral resistance could rapidly develop in a previously single-resistant strain as a result of mutation, drug response, or gene exchange with another virus. (medicaldesignandoutsourcing.com)
A second study, conducted by Catherine Moore and colleagues in the United Kingdom, examined an outbreak of oseltamivir resistant (OR) pandemic H1N1 infection in a hematology unit in the UK. (medicaldesignandoutsourcing.com)
The 2009 pandemic H1N1 virus was inherently resistant to adamantine, but was susceptible to and treated with oseltamivir. (medicaldesignandoutsourcing.com)
However, by October 2009, emergence of OR H1N1 had been documented in rare patients on oseltamivir therapy. (medicaldesignandoutsourcing.com)
In the hematology unit that Moore and colleagues studied, eight of the 11 pandemic H1N1 virus infections were resistant to oseltamivir, with half of those cases resulting from direct transmission of the resistant virus. (medicaldesignandoutsourcing.com)
Guidelines may need to be changed to include active screening for the [OR] mutation in hematology patients diagnosed with H1N1 and other patients who are immunocompromised when oseltamivir is used. (medicaldesignandoutsourcing.com)
A study of 410 young adults has found that a Chinese herbal combination called maxingshigan-yinqiaosan treats H1N1 virus infections more successfully than the conventional drug oseltamivir (Tamiflu). (plantmedicines.org)
Oseltamivir, produced by Roche under the trademark Tamiflu, is considered by the CDC, the World Health Organization and other agencies as the 'go-to' medication for treating H1N1. (plantmedicines.org)
However, the H1N1 virus has become increasingly resistant to oseltamivir. (plantmedicines.org)
The World Health Organization reported that 314 strains of the H1N1 virus had become resistant to oseltamivir as of December 2010. (plantmedicines.org)
The 2010 Victorian influenza season was characterized by normal seasonal influenza activity and the dominance of the pandemic A(H1N1) 2009 strain. (who.int)
The World Health Organization Collaborating Centre for Reference and Research on Influenza tested 403 isolates of which 261 were positive for influenza, 250 of which were influenza A and 11 were influenza B. Ninety-two per cent of the influenza A viruses were pandemic A(H1N1) 2009, and following antigenic analysis all of these were found to be similar to the current vaccine strain. (who.int)
This correlates with the seeming disappearance of the previously circulating H1N1 strain (called "seasonal") that was resistant to oseltamivir. (chestervetclinic.com)
A resistance of A/H1N1 influenza viruses to oseltamivir has recently emerged in a number of countries. (biomedcentral.com)
As children have the highest incidence of influenza infection and are at high risk of severe disease, the aim of this study was to evaluate the clinical importance and the impact on the households of oseltamivir-resistant seasonal A/H1N1 influenza virus in an otherwise healthy pediatric population. (biomedcentral.com)
No significant differences were found in terms of clinical importance or impact on the households between the children with oseltamivir-resistant seasonal A/H1N1 influenza virus and those with the wild-type. (biomedcentral.com)
Similarly, during the 2009-2010 novel influenza A H1N1 pandemic, preliminary data from a limited number of states indicated a high prevalence of virus strains resistant to oseltamivir. (medscape.com)
Enteric absorption and pharmacokinetics of oseltamivir in critically ill patients with pandemic (H1N1) influenza. (cdc.gov)

Upcoming strains resistant to present drugs, predominantly oseltamivir (Tamiflu), appear to be a threat and make the progress of alternate antivirals an imperative public health issue. (healthjockey.com)
So although the H3N2 strains are sensitive to Tamiflu, it's not much help. (virology.ws)
For these reasons, oseltamivir (Tamiflu) remains the preferred treatment option, unless an oseltamivir-resistant flu strain is suspected. (hdrxservices.com)
Probably the same experts claiming oseltamivir (marketed as Tamiflu) is ineffective against seasonal flu. (caymannewsservice.com)
Oseltamivir is an anti-viral neuraminidase inhibitor (Tamiflu) used to treat influenza infections. (herbs.news)
The group taking the Chinese herbal medication had 37% faster fever reduction over untreated patients, while oseltamivir (Tamiflu) reduced fevers by 34% over the untreated group. (plantmedicines.org)
Furthermore, combined treatment with oseltamivir (Tamiflu) and the Chinese herbal formula reduced fevers by 47%, and 19% sooner than oseltamivir alone. (plantmedicines.org)
One form of the protein makes influenza virus resistant to Oseltamivir (Tamiflu®) Don't worry, these proteins aren't from H5N1, but they do come from a related influenza virus that also infects birds. (digitalworldbiology.com)
Oseltamivir (Tamiflu) resistance emerged in the United States during the 2008-2009 influenza season, and the CDC issued revised interim recommendations for antiviral treatment and prophylaxis of influenza. (medscape.com)

Development of Digital Droplet PCR Targeting the Influenza H3N2 Oseltamivir-Resistant E119V Mutation and Its Performance through the Use of Reverse Genetics Mutants. (sciensano.be)
And the other strain currently circulating, H3N2? (virology.ws)
Most H3N2 strains are resistant to Rimantadine, which is why it has not been used much in recent years. (virology.ws)
This season, influenza B is prominent in the Americas and Africa, and influenza A H3N2 comprises half the reported cases Prof. Emerita, Stanford University in Europe and Australia, and more than 75% of strains in ChinaA. (chestervetclinic.com)
In temperate South America, numbers of influenza cases began to increase in May, peaking around July with the largest numbers seen for A(H3N2), but showing a second peak in August with more influenza B strains and untyped influenza A strains (Figure 1). (chestervetclinic.com)
However, a new virus, variant H3N2 (H3N2v), associated with pigs and originally discovered in 2011, has cropped up this year in some human outbreaks periodically since July, 2012.1,B Although the strains of influenza circulating globally now are genetically slightly different from those in the current vaccine, the CDC feels that there will be significant cross-reactive protection, so they recommend that the vaccines not be changed. (chestervetclinic.com)

CS-8958 is highly effective for the treatment and prophylaxis of infection with H5N1 influenza viruses, including oseltamivir-resistant mutants. (healthjockey.com)
and the A/Shanghai/2/2013 viruses was completely inhibited at 250 ?M and 31.25 ?M of oseltamivir carboxylate, respectively. (flutrackers.com)
They noted that baloxavir showed nanomolar antiviral activity against influenza A and B viruses in preclinical models, including "strains resistant to current antiviral agents. (medpagetoday.com)
Rapid evolution of influenza RNA virus has resulted in limitation of vaccine effectiveness, increased emergence of drug-resistant viruses and occurrence of pandemics. (nairaland.com)
However, it is a last-resort medication to treat the novel or re-emerging influenza viruses that are resistant to certain antivirals, like oseltamivir [ 1 ]. (springer.com)
Drug-resistant viruses from favipiravir-treated patients have not been identified so far. (springer.com)
Xofluza is a first-in-line, single-dose oral medicine designed with a novel mechanism of action that has shown effectiveness to a variety of influenza viruses, in non clinical studies, including in vitro activity against oseltamivir-resistant strains and avian strains (H7N9, H5N1). (pharma-industry-review.com)
Drug-resistant viruses are not 'reactions' to overuse of the drug. (virology.ws)
Usually the drug-resistant mutants are already in the host, and outpace other drug-sensitive viruses. (virology.ws)
In an accompanying editorial, Frederick G. Hayden, MD, of the University of Virginia School of Medicine, and Menno D. de Jong, MD, of the University of Amsterdam in the Netherlands, agreed that increasingly detailed monitoring and creative preventive and therapeutic choices will be required as unpredictable and antiviral-resistant influenza viruses continue to appear. (medicaldesignandoutsourcing.com)
Three viruses (0.9%) were found to be oseltamivir resistant due to an H275Y mutation in the neuraminidase gene. (who.int)
To the researchers' surprise, increased expression of IFITMs also blocked the replication of completely different viruses, including strains of West Nile and Dengue viruses. (drugdiscoveryopinion.com)
B viruses with reduced susceptibility to oseltamivir show that ongoing NAI susceptibility surveillance is essential. (who.int)
Of 1015 sequences of HPAI A (H5N1) viruses collected in the United States during 2022, eight viruses (0.8%) had a molecular marker of drug resistance to an FDA-approved antiviral: three adamantane-resistant (M2-V27A), four oseltamivir-resistant (NA-H275Y), and one baloxavir-resistant (PA-I38T). (cdc.gov)
More than 20 strains of Influenza A viruses are identified, based on their difference in protein spikes. (vetcos.com)

Antibiotic resistance is a major subset of AMR, that applies specifically to bacteria that become resistant to antibiotics. (wikipedia.org)
Resistance can appear spontaneously because of random mutations, but also arises through spreading of resistant genes through horizontal gene transfer. (wikipedia.org)
Antifungal resistance is a subset of AMR, that specifically applies to fungi that have become resistant to antifungals. (wikipedia.org)
Rising drug resistance is caused mainly by use of antimicrobials in humans and other animals, and spread of resistant strains between the two. (wikipedia.org)
While monitoring influenza virus resistance as it develops, researchers are prioritizing further investigations to decrease the risk of resistant strains. (pharmacytimes.com)
While the spread of influenza strains with resistance to one class of drugs has been well documented in recent years, a new report from Larisa Gubareva, MD, PhD and colleagues at the Centers for Disease Control and Prevention (CDC) and at health agencies in West Virginia, Texas, and Canada, confirms that dual resistance can emerge in several ways and has been on the rise during the past three years. (medicaldesignandoutsourcing.com)
Of course, occasional resistance can arise and patients who fail to improve after a week of therapy should be evaluated for drug resistant strains, as well as for other complications. (chestervetclinic.com)
Circulating strains of influenza A virus with resistance to existing neuraminidase inhibitors have already been discovered, and new molecular targets would provide additional protection in the event of a fresh outbreak. (drugdiscoveryopinion.com)

Vaccines against seasonal influenza are reformulated annually in order to contain the most recently circulating strains. (medscape.com)

Since the 2005-2006 influenza season, amantadine and rimantadine are no longer recommended by the Centers for Disease Control and Prevention (CDC) because circulating strains of influenza virus have proved resistant. (medscape.com)
A second-line alternative is a combination of oseltamivir plus rimantadine, rather than oseltamivir alone. (medscape.com)

A study headed by a University of Wisconsin-Madison virologist claims that a new compound could be extremely effectual against the pathogenic H5N1 avian influenza virus, counting a few drug-resistant strains. (healthjockey.com)
While working with mice, the experts apparently discovered that a single intranasal dose of CS-8958 given two hours following infection with H5N1 influenza virus supposedly led to elevated survival rate and lower virus levels as compared to a usual five-day course of oseltamivir. (healthjockey.com)
CS-8958 was also believed to be effectual against extremely pathogenic and oseltamivir-resistant strains of H5N1 virus. (healthjockey.com)
During 2003-05 period the A (H5N1) strain of bird flu virus infected 117 people out of which 64 died. (vetcos.com)
Public health officials remain concerned that the genes of Influenza A (H5N1) strain virus which is slightly infectious to human beings could yet mix with a human strain to create a new strain that could spread widely in human population. (vetcos.com)
Actualización sobre el virus la influenza aviar A (H5N1) en los seres humanos. (cdc.gov)

Early administration of oral oseltamivir increases the benefits of influenza treatment. (cdc.gov)

Due to its high mutation rate, the influenza virus has rapidly and continuously evolved and has now generated new strains that are resistant to anti-viral medications commonly used today. (herbs.news)
A Nature Communications paper showed a mutation in newly emerged H7N9 influenza can render it resistant to the only class of drugs active against the virus, without affecting its ability to spread in animals. (sciencemediacentre.org)
New strains of flu virus arise not through mutation but through recombination of genes. (vetcos.com)

However, there are three studies where favipiravir-resistant mutants were obtained in vitro. (springer.com)

OS, oseltamivir susceptible. (cdc.gov)
As IMPDH inhibitors targeted on host cells, it would be less susceptible for selection of drug-resistant strains. (biomedcentral.com)

In the present study, we developed the broad-spectrum antiviral activity of N30 in vitro, including oseltamivir-resistant strains and amantadine-resistant strains of influenza virus, coxsackie B virus, coronavirus, and respiratory syncytial virus. (biomedcentral.com)

In addition to a significantly shorter median time to alleviation of symptoms compared with placebo, baloxavir was linked with significantly greater reduction of viral load 1 day after initiation compared with oseltamivir and placebo groups. (medpagetoday.com)
Herbal extracts that contain compounds called pentacyclic triterpenes have exhibited higher anti-viral activity than oseltamivir. (herbs.news)
For this reason, seasonal vaccines need to be annually reformulated based upon the forecasting of viral strains that will circulate in the coming influenza season. (distantreader.org)
Oseltamivir is an inhibitor of neuraminidase, which is a glycoprotein on the surface of the influenza virus that destroys the infected cell's receptor for viral hemagglutinin. (medscape.com)
Antigenic drift refers to relatively minor, progressive mutations in preexisting combinations of H and NA antigens, resulting in the frequent emergence of new viral strains. (msdmanuals.com)

WHO has recommended vaccine strains for the 2009-10 Northern Hemisphere trivalent influenza vaccine, and FDA has made the same recommendations for the U.S. influenza vaccine. (cdc.gov)

For the trivalent formulation influenza vaccines, two strains of influenza A and one of influenza B are included. (medscape.com)

In contrast to both teas, oseltamivir carboxylate (OC) demonstrated high potency against the growth of A/Narita/1/09 (IC(50) of 3.83nM) and A/Yamaguchi/20/06 (IC(50) of 11.57nM) but not against that of A/Kitakyushu/10/06 bearing a His274-to-Tyr substitution (IC(50) of 15.97μM). (nairaland.com)

Bacteria frequently reported include Streptococcus pneumoniae and Staphylococcus aureus , including methicillin-resistant strains in some cases. (clinlabnavigator.com)

Some studies have also reported that certain herbal extracts can inhibit the replication of oseltamivir-resistant strains. (herbs.news)
Based on these findings, we further confirmed that N30 provided a strong inhibition on the replication of respiratory syncytial virus, coronavirus, enterovirus 71 and a diverse strains of coxsackie B virus. (biomedcentral.com)

Furthermore, over time, antigenic variation (antigenic drift) within a subtype may be so marked that infection or vaccination with one strain may not induce immunity to distantly related strains of the same subtype. (canada.ca)
Pandemics can result from antigenic shift because antibodies against other strains (resulting from vaccination or natural infection) provide little or no protection against the new strain. (msdmanuals.com)

All three resistant mutants carried mutations in their polymerase gene. (springer.com)
Oseltamivir was least potent at inhibiting NA activity, while the investigational NA inhibitor AV5080 was most potent, including against NA mutants. (cdc.gov)

In this work we identify a new class of compounds, structurally similar to the anti-inflammation drug antrafenine, with good potency against influenza A strains. (bvsalud.org)

By 2013, approximately 45% of all IAV subtypes were resistant to amantadine. (pharmacytimes.com)

However, some strains, capable of causing disease, are pathogenic clones in healthy hosts [23]. (immune-source.com)

2 The pandemic strain continued to be dominant around the world into the 2009/2010 northern hemisphere influenza season and there was considerable interest in the epidemiology of a likely second southern hemisphere pandemic wave during the 2010 influenza season. (who.int)

Strategies to reduce emergence of resistant strains, such as higher dose oseltamivir regimens, need further examination. (eurekaselect.com)
A higher dose of oseltamivir (150 mg twice daily) and nonconventional modes of ventilation may have improved the outcome in these patients. (medscape.com)

So far, it looks like this assay is very effective with strains in the U.S., and we expect it to have the same accuracy with strains around the world,'' said Engelthaler, the former State Epidemiologist for Arizona and former State of Arizona Biodefense Coordinator. (tgen.org)

Glycopeptides are used for Staphylococcus aureus (S aureus) infections that have become resistant to standard antibiotics. (adam.com)
Persistence of the Staphylococcus aureus epidemic European fusidic acid-resistant impetigo clone (EEFIC) in Belgium. (sciensano.be)

In 1999 a different strain of bird flu virus identified as A (H9N2) infected two people in Hong Kong. (vetcos.com)

Antibiotic overuse contributes to the emergence of drug-resistant organisms. (medscape.com)

Health care providers can minimize spread of resistant infections by use of proper sanitation and hygiene, including handwashing and disinfecting between patients, and should encourage the same of the patient, visitors, and family members. (wikipedia.org)
Neuropsychiatric events: Patients with influenza, including those receiving oseltamivir phosphate capsules, particularly pediatric patients, may be at an increased risk of confusion or abnormal behavior early in their illness. (nih.gov)

In April 2003, a Dutch veterinarian working in a farm infected with bird flu virus of H7 strain died of pneumonia. (vetcos.com)

TB genotyping was performed to determine if the MDR TB cases were the same strain, which could suggest recent transmission or an outbreak. (cdc.gov)
TB strains were in fact all similar, the main conclusion was that an outbreak of MDR TB had occurred in a camp already characterized by elevated rates of TB. (cdc.gov)

DOT is expensive but should always be used in the treatment of drug-resistant TB to ensure adherence. (cdc.gov)
The research published in the journal Antiviral Research showed that Umckaloabo is a promising, antiviral natural medicine even against some drug-resistant strains of flu virus. (drmichellecook.com)
Health Advisory: Increase in Extensively Drug-Resistant (XDR) Shigellosis in the U.S. (snohd.org)
How does a single nucleotide change make influenza virus resistant to a drug? (digitalworldbiology.com)

this increases the percentage of resistant bacteria which continue growing. (wikipedia.org)

These new strains may cause seasonal epidemics because protection by antibody generated to the previous strain is decreased. (msdmanuals.com)

Oseltamivir use in pregnancy: Risk of birth defects, preterm delivery, and small for gestational age infants. (cdc.gov)

Proteins expression for every group of vectors was examined in five strains of 1 Shot BL21 Star (DE3) (ThermoFisher), Arctic Express (Stratagene), Origami B(DE3) (Novagen), SHuffle T7(New England BioLabs), and SHuffle K12 competent AB1010 cell signaling cells (New England BioLabs). (immune-source.com)

Organisms10

Diseases2

Chemicals and Drugs17

Analytical, Diagnostic and Therapeutic Techniques and Equipment3

Phenomena and Processes9

Information Science1

Health Care2

Zanamivir15

H1N131

Tamiflu9

H3N26

Viruses15

Resistance8

Seasonal influenza1

Rimantadine2

H5N16

Oral oseltamivir1

Mutation3

Obtained in vitro1

Susceptible2

Vitro1

Viral5

Vaccine1

Trivalent1

Carboxylate1

Methicillin-resistant1

Replication2

Infection2

Mutants2

Potency1

Amantadine1

Pathogenic1

Pandemic strain1

Higher dose2

Assay1

Staphylococcus2

19991

Emergence of drug-resistant1

Patients2

Bird flu1

Outbreak2

Drug4

Increases1

Antibody1

Pregnancy1

Proteins1