[ China Pharmaceutical Network Health Health ] Influenza virus belongs to the Orthomyxoviridae family and is a single-stranded negative-strand RNA virus. The virus structure can be divided into three parts: envelope, matrix protein and core from the outside. The currently used anti-influenza virus drugs mainly include NAI and M2 ion channel blockers. For children, how do you choose a flu medicine?
The flu is an acute respiratory infection caused by the flu virus. The neuraminidase inhibitor (NAI), which has been marketed in the past 10 years, has achieved certain effects in the prevention and treatment of influenza. Among them, oseltamivir has been widely used in adults and children, and peramivir has been used as the first intravenous NAI. China is listed and applied to children. Now it mainly introduces the mechanism, characteristics and application status of commonly used NAI and other anti-influenza drugs.
1 structure of influenza virus
The influenza virus belongs to the Orthomyxoviridae family and is a single-stranded negative-strand RNA virus. The virus structure can be divided into three parts: envelope, matrix protein and core from the outside. The matrix protein constitutes the outer shell of the virus, and there are matrix proteins (M1) and membrane proteins (M2) in the skeleton. The M2 protein has an ion (mainly sodium ion) channel and regulates the pH in the membrane, but in a small amount. According to the difference between viral nucleoprotein and matrix protein antigenic determinants, influenza viruses are classified into type A (A), type B (B), and type C (C). Influenza A is the most prevalent and pathogenic, and type C is less common. Hemagglutinin (HA) and neuraminidase (NA) are embedded in the envelope of influenza A virus. They are further classified into H1N1, H3N2, H5N1 and H7N9 according to the difference of the two glycoproteins. The isoforms, these two proteins play an important role in the invasion and spread of influenza viruses into host cells.
2 commonly used anti-influenza drugs
The currently used anti-influenza virus drugs mainly include NAI and M2 ion channel blockers.
2.1NAI
After the influenza virus infects the epithelial cells, it replicates inside the cells to produce a new virus, and then detaches from the host cells under the hydrolysis of NA, continuing to infect other healthy human cells. NAI blocks the spread of viral particles from the surface of infected host cells by inhibiting the NA on the viral envelope, thereby preventing the spread of the virus between the host cells. There are currently three NAIs available in the country: Oseltamivir, Zanamivir and Peramivir. Laninamivir was launched in Japan in 2010 and has not been approved for the treatment of influenza in China. NAI is used to treat influenza A and B, and it also inhibits the H5N1 and H7N9 avian influenza viruses. It is currently the main anti-influenza virus.
2.1.1 oseltamivir
In 1999, oseltamivir was first used in the United States to treat influenza in adults and adolescents. Since then, it has been used in influenza treatment for children over one year of age in 2000 and has been used for preventive treatment since 2005. Currently, the US Food and Drug Administration (FDA) has approved oseltamivir for the treatment and prevention of children aged 1 year and older, and neonates >14 days old are only used for treatment. Oseltamivir has only oral dosage forms. Currently, there are two dosage forms of granules (15mg and 25mg) and capsules (75mg). In capsule-only dosage, children can take the capsules apart and the tablets are poured into the required dose. Take a good taste in liquids (such as chocolate syrup, corn syrup, etc.) [1]. The oseltamivir is rapidly absorbed in the gastrointestinal tract after oral administration, and is rapidly converted into the active metabolite oseltamivir carboxylic acid via the liver and/or intestinal wall. The peak concentration is 3-4 hours, and the adult elimination half-life is about 7.7. h. Oseltamivir has a high oral bioavailability, with at least 75% being converted to oseltamivir carboxylic acid by first pass metabolism and <5% being reabsorbed in the form of oseltamivir carboxylic acid in urine [2 ].
Oseltamivir is currently the most widely used anti-influenza drug for adults and children. The optimal administration time is within 48 hours of the onset of flu symptoms. The recommended course of treatment is 5 days. If the symptoms are severe, the longest course of treatment can be up to 10 days. In a large randomized trial of children, the use of oseltamivir for the treatment of influenza compared with placebo was shortened by approximately 1 day, significantly reducing the incidence of otitis media and the use of antibiotics [3]. A systematic review in 2014 found that taking oseltamivir compared with placebo reduced the average duration of flu symptoms in previously healthy children by approximately 29 hours and adults by approximately 17 hours [4]. Applying oseltamivir as soon as possible after onset may work better. Studies have shown that taking oseltamivir for children aged 1-3 years within 24 hours of flu symptoms can reduce the average duration of symptoms by 3.5 days [5]; starting within 5 days of symptom onset can shorten the average duration of symptoms by 1d. [6]. However, oseltamivir does not shorten the duration of symptoms in children with bronchial asthma (referred to as asthma) [4].
The safety of oseltamivir in children is better [3]. The literature reports that children's adverse reactions are mainly gastrointestinal reactions such as nausea and vomiting and rash [7], and do not increase neurological adverse events and mortality for infants under 12 months [8,9].
NAI, including oseltamivir, has rare neurological adverse events, including delirium, hallucinations, confusion, behavioral abnormalities, convulsions, and encephalitis, which usually occur suddenly and quickly improve. NAI is also rare to cause serious skin adverse events (including toxic epidermal release syndrome, StevensJohnson syndrome, polymorphic erythema, etc.) and death. These adverse events are not triggered by the influenza virus itself [1,10].
Oseltamivir can be used in infants and young children. The recommended oral dose for patients <1 year old is 3 mg/kg twice daily. In premature infants, due to immature renal function, drug clearance is slow, and the recommended dose for term infants may lead to excessive drug concentrations in preterm infants. According to limited research data from the National Anti-Viological Research Collaborative Group of the National Institute of Allergy and Infectious Diseases, the oral dose of oseltamivir in infants with gestational age <38 weeks, 38-40 weeks, and >40 weeks was 1.0 mg/kg. 2 times / d, 1.5 mg / kg, 2 times / d and 3.0 mg / kg, 2 times / d [1].
2.1.2 Zanamivir
Zanamivir was the first NAI to be developed and was approved by the US FDA in 1999. The inhibition of influenza virus by zanamivir is carried out in a slow-binding manner and is highly specific and can be used for the prevention of children over 5 years old and for children over 7 years old. Its oral bioavailability is low (1% to 5%), so it is only used for inhaled administration [6,7]. After the intranasal or oral inhalation of zanamivir, an average of 10% to 20% is absorbed, and the maximum plasma concentration is reached in 1 to 2 hours. The bioavailability is 2% on average, and about 90% is excreted in the urine by the prototype. The half-life is about 3h.
Zanamivir can effectively improve the symptoms of flu in the short term, and the effect is better within 2 days from the beginning of the symptoms. A meta-analysis showed that zanamivir did not shorten the mean duration of symptoms in children with influenza compared with the control, but it was shortened by about 1.5 days in adults [11]. The dosage form is dry powder inhalation, and the adverse reactions are less, mainly nasal symptoms, which may cause bronchospasm and allergic reactions. It is difficult for some younger age and patients with respiratory diseases to deliver the drug to the infected site, and occasionally causes dry powder inhalation related cough. Its intravenous preparations are in clinical research and are expected to be used in the treatment of children with severe influenza in the future [1]. Zanamivir is not recommended for children under 5 years of age and is not recommended for children with basic lung diseases such as asthma [1,12].
2.1.3 peramivir
Peramivir is a cyclopentane derivative designed and synthesized based on the analysis of the interaction mechanism and structure-activity relationship between sialic acid, zanamivir, oseltamivir and NA. Its four polar groups act on different active site regions of the influenza virus NA structure, strongly inhibiting the activity of NA, preventing the replication and release of the progeny virus particles in the host cell, and the binding degree is good. A new and efficient NAI is effective for both Influenza A and Influenza B. China completed all clinical studies in 2011 and approved the marketing of peramivir injection in April 2013. It is the first NAI approved for intravenous use in the market and can be used in all age groups in China. During the 2009 H1N1 epidemic, the United States temporarily approved the drug for treatment in children and adults, and the patient was well tolerated [13]. In December 2014, the United States officially approved that peramivir is suitable for children 18 years of age and older, and patients with flu symptoms <2d are not available in children in the United States.
The recommended dose for children is 10mg/kg, and the single maximum dose is 600mg. It is recommended to administer a single dose. If the symptoms are severe, it can be administered continuously according to the condition, once/d, 1~5d. The drug is characterized by rapid onset and long duration of action. Studies have shown that the efficacy of a single dose of peramivir is comparable to that of oseltamivir 5d [14]. Because of intravenous administration, peramivir is suitable for use in patients with severe influenza and in children who cannot be taken orally [12]. A number of clinical studies have shown that peramivir is similar to oseltamivir phosphate against influenza virus [14,15,16]. A Japanese clinical study showed that 117 children (125d to 15 years old) were treated with peramivir for the treatment of A(H1N1) infection and adverse drug reactions were resolved or improved quickly [17].
2.2M2 ion channel blocker
M2 ion channel blockers include amantadine and rimantadine, which inhibit viral replication by blocking the ion channel of the influenza virus M2 protein. Because the influenza B virus lacks M2 membrane protein, these drugs are only used to treat influenza A and are not effective against influenza B. These drugs have many clinical adverse reactions, which can cause adverse reactions in the central nervous system, such as dizziness, anxiety, depression, headache, etc., and even hallucinations and convulsions; gastrointestinal reactions include nausea and vomiting. In addition, the amino acid mutation at position 31 of the influenza virus M2 ion channel protein caused high drug resistance [18]. Central nervous system adverse reactions and drug resistance problems limit the clinical application of this class of drugs in pediatrics [12].
2.3 Chinese medicine
During the H1N1 and H7N9 epidemics in 2009, China recommended and approved the application of some Chinese herbal medicines [19,20]. Among them, honeysuckle, forsythia, and nasturtium are common drugs used in the prevention and treatment of influenza prescriptions. Traditional Chinese medicine starts from the whole, and its role in syndrome differentiation is positive in the prevention and treatment of influenza. The combination of traditional Chinese and Western medicine for the treatment of influenza still needs to be continuously explored and gradually internationalized.
3 drug selection for preventing influenza
Although vaccination is the best way to prevent influenza virus infection, in the case of influenza outbreaks, people who cannot be used for vaccine prevention and some key children can use drug prevention. Recommended population: (1) high-risk children who cannot be vaccinated against influenza, or children with immune abnormalities and no response to vaccines; (2) high-risk children within 2 weeks of vaccination; (3) high-risk children with unimmunized or age < Family members or caregivers who are intimately contacted by infants and young children for 24 months; (4) used to control influenza outbreaks in unimmunized children or in child gathering places (such as kindergartens); (5) after exposure of family members Prevention, prevention of high-risk flu complications and close contact with influenza patients; (6) community or family outbreaks of influenza, influenza strains and vaccines do not match [12]. Both oseltamivir and zanamivir can be used for prophylaxis. For those who are eligible for prophylactic use, it is recommended to use it early (as much as possible within 48 hours of exposure), until 7 to 10 days after the last exposure; within 48 hours after exposure For drug users, prophylactic administration is still recommended [12].
4 drug selection for the treatment of influenza
For most previously healthy children, the flu is a mild and self-limiting infection that usually does not require antiviral medication. Excessive drug treatment may help the virus to develop resistance, and may increase the adverse effects of the drug itself on the body. The following conditions are suitable for anti-influenza drug treatment.
4.1 Recommended anti-influenza drugs
(1) Children with laboratory pathogens confirmed or highly suspected of influenza and who have high risk factors for complications, regardless of the underlying disease, influenza vaccine immune status and the severity of influenza, should be treated within 48 hours of onset; (2) In the laboratory confirmed or highly suspected flu hospitalized children, regardless of the underlying disease, influenza vaccine immune status, if the influenza virus test is positive after 48 hours of onset, antiviral drugs are also recommended.
4.2 Consider using anti-flu drugs
(1) High-risk factors for clinical suspicion of flu, no improvement in morbidity >48h, and influenza outpatients with positive specimens after 48h; (2) clinically highly suspected or laboratory confirmed influenza, uncomplicated risk factors, and onset < An anti-viral medication may be considered for a 48-hour visit, but an outpatient who wishes to shorten the course of the disease and thereby reduce the risk of complications, or who have a close history of exposure to high-risk influenza patients. Children with significant symptoms and persistence for >48 hours can also benefit from antiviral therapy [12].
The choice of antiviral drugs is mainly based on the characteristics and drug resistance of the drugs.
The resistance of influenza viruses is constantly changing, and the sensitivity of drugs should be based on virus monitoring results. There is resistance in oseltamivir. NAI is effective for most seasonal flu in recent years and has a certain effect on bird flu. The WHO tested the NAI resistance of 13312 strains of influenza virus collected between 2014 and 2015. The total resistance rate of all viruses to oseltamivir, zanamivir, palamivir and lanimivir was only about It is 0.5%, which is down from 1.9% in 2013-2014, close to 0.6% in 2012-2013. Drug-resistant strains may still be sensitive to other NAI when they are resistant to oseltamivir [21].
NAI treatment should be applied as soon as possible within 48 hours of the onset of flu symptoms. Oseltamivir is widely used in the treatment of adults and children. Zanamivir is intended for children and adults over 7 years of age, but not for patients with basic lung diseases such as asthma [1]. There are relatively few clinical studies on the use of peramivir in children, and limited research on drug resistance. It can be used in children of all ages in China and can be used in critically ill patients and children who cannot be orally or cannot be atomized. The M2 ion channel blocker is only effective against influenza A, but the drug resistance monitoring shows that it is almost completely resistant to type A H1N1 (2009) and type A H3N2, and has a high resistance rate to seasonal influenza in recent years, so it is not currently used. Empirical antiviral therapy for influenza [1]. Chinese medicine can be used for the treatment of mild cases or for the treatment of critically ill patients.
Original title: How to choose the flu drugs commonly used in children is related to the life of a child
(How can parents help children choose common flu drugs?)
The flu is an acute respiratory infection caused by the flu virus. The neuraminidase inhibitor (NAI), which has been marketed in the past 10 years, has achieved certain effects in the prevention and treatment of influenza. Among them, oseltamivir has been widely used in adults and children, and peramivir has been used as the first intravenous NAI. China is listed and applied to children. Now it mainly introduces the mechanism, characteristics and application status of commonly used NAI and other anti-influenza drugs.
1 structure of influenza virus
The influenza virus belongs to the Orthomyxoviridae family and is a single-stranded negative-strand RNA virus. The virus structure can be divided into three parts: envelope, matrix protein and core from the outside. The matrix protein constitutes the outer shell of the virus, and there are matrix proteins (M1) and membrane proteins (M2) in the skeleton. The M2 protein has an ion (mainly sodium ion) channel and regulates the pH in the membrane, but in a small amount. According to the difference between viral nucleoprotein and matrix protein antigenic determinants, influenza viruses are classified into type A (A), type B (B), and type C (C). Influenza A is the most prevalent and pathogenic, and type C is less common. Hemagglutinin (HA) and neuraminidase (NA) are embedded in the envelope of influenza A virus. They are further classified into H1N1, H3N2, H5N1 and H7N9 according to the difference of the two glycoproteins. The isoforms, these two proteins play an important role in the invasion and spread of influenza viruses into host cells.
2 commonly used anti-influenza drugs
The currently used anti-influenza virus drugs mainly include NAI and M2 ion channel blockers.
2.1NAI
After the influenza virus infects the epithelial cells, it replicates inside the cells to produce a new virus, and then detaches from the host cells under the hydrolysis of NA, continuing to infect other healthy human cells. NAI blocks the spread of viral particles from the surface of infected host cells by inhibiting the NA on the viral envelope, thereby preventing the spread of the virus between the host cells. There are currently three NAIs available in the country: Oseltamivir, Zanamivir and Peramivir. Laninamivir was launched in Japan in 2010 and has not been approved for the treatment of influenza in China. NAI is used to treat influenza A and B, and it also inhibits the H5N1 and H7N9 avian influenza viruses. It is currently the main anti-influenza virus.
2.1.1 oseltamivir
In 1999, oseltamivir was first used in the United States to treat influenza in adults and adolescents. Since then, it has been used in influenza treatment for children over one year of age in 2000 and has been used for preventive treatment since 2005. Currently, the US Food and Drug Administration (FDA) has approved oseltamivir for the treatment and prevention of children aged 1 year and older, and neonates >14 days old are only used for treatment. Oseltamivir has only oral dosage forms. Currently, there are two dosage forms of granules (15mg and 25mg) and capsules (75mg). In capsule-only dosage, children can take the capsules apart and the tablets are poured into the required dose. Take a good taste in liquids (such as chocolate syrup, corn syrup, etc.) [1]. The oseltamivir is rapidly absorbed in the gastrointestinal tract after oral administration, and is rapidly converted into the active metabolite oseltamivir carboxylic acid via the liver and/or intestinal wall. The peak concentration is 3-4 hours, and the adult elimination half-life is about 7.7. h. Oseltamivir has a high oral bioavailability, with at least 75% being converted to oseltamivir carboxylic acid by first pass metabolism and <5% being reabsorbed in the form of oseltamivir carboxylic acid in urine [2 ].
Oseltamivir is currently the most widely used anti-influenza drug for adults and children. The optimal administration time is within 48 hours of the onset of flu symptoms. The recommended course of treatment is 5 days. If the symptoms are severe, the longest course of treatment can be up to 10 days. In a large randomized trial of children, the use of oseltamivir for the treatment of influenza compared with placebo was shortened by approximately 1 day, significantly reducing the incidence of otitis media and the use of antibiotics [3]. A systematic review in 2014 found that taking oseltamivir compared with placebo reduced the average duration of flu symptoms in previously healthy children by approximately 29 hours and adults by approximately 17 hours [4]. Applying oseltamivir as soon as possible after onset may work better. Studies have shown that taking oseltamivir for children aged 1-3 years within 24 hours of flu symptoms can reduce the average duration of symptoms by 3.5 days [5]; starting within 5 days of symptom onset can shorten the average duration of symptoms by 1d. [6]. However, oseltamivir does not shorten the duration of symptoms in children with bronchial asthma (referred to as asthma) [4].
The safety of oseltamivir in children is better [3]. The literature reports that children's adverse reactions are mainly gastrointestinal reactions such as nausea and vomiting and rash [7], and do not increase neurological adverse events and mortality for infants under 12 months [8,9].
NAI, including oseltamivir, has rare neurological adverse events, including delirium, hallucinations, confusion, behavioral abnormalities, convulsions, and encephalitis, which usually occur suddenly and quickly improve. NAI is also rare to cause serious skin adverse events (including toxic epidermal release syndrome, StevensJohnson syndrome, polymorphic erythema, etc.) and death. These adverse events are not triggered by the influenza virus itself [1,10].
Oseltamivir can be used in infants and young children. The recommended oral dose for patients <1 year old is 3 mg/kg twice daily. In premature infants, due to immature renal function, drug clearance is slow, and the recommended dose for term infants may lead to excessive drug concentrations in preterm infants. According to limited research data from the National Anti-Viological Research Collaborative Group of the National Institute of Allergy and Infectious Diseases, the oral dose of oseltamivir in infants with gestational age <38 weeks, 38-40 weeks, and >40 weeks was 1.0 mg/kg. 2 times / d, 1.5 mg / kg, 2 times / d and 3.0 mg / kg, 2 times / d [1].
2.1.2 Zanamivir
Zanamivir was the first NAI to be developed and was approved by the US FDA in 1999. The inhibition of influenza virus by zanamivir is carried out in a slow-binding manner and is highly specific and can be used for the prevention of children over 5 years old and for children over 7 years old. Its oral bioavailability is low (1% to 5%), so it is only used for inhaled administration [6,7]. After the intranasal or oral inhalation of zanamivir, an average of 10% to 20% is absorbed, and the maximum plasma concentration is reached in 1 to 2 hours. The bioavailability is 2% on average, and about 90% is excreted in the urine by the prototype. The half-life is about 3h.
Zanamivir can effectively improve the symptoms of flu in the short term, and the effect is better within 2 days from the beginning of the symptoms. A meta-analysis showed that zanamivir did not shorten the mean duration of symptoms in children with influenza compared with the control, but it was shortened by about 1.5 days in adults [11]. The dosage form is dry powder inhalation, and the adverse reactions are less, mainly nasal symptoms, which may cause bronchospasm and allergic reactions. It is difficult for some younger age and patients with respiratory diseases to deliver the drug to the infected site, and occasionally causes dry powder inhalation related cough. Its intravenous preparations are in clinical research and are expected to be used in the treatment of children with severe influenza in the future [1]. Zanamivir is not recommended for children under 5 years of age and is not recommended for children with basic lung diseases such as asthma [1,12].
2.1.3 peramivir
Peramivir is a cyclopentane derivative designed and synthesized based on the analysis of the interaction mechanism and structure-activity relationship between sialic acid, zanamivir, oseltamivir and NA. Its four polar groups act on different active site regions of the influenza virus NA structure, strongly inhibiting the activity of NA, preventing the replication and release of the progeny virus particles in the host cell, and the binding degree is good. A new and efficient NAI is effective for both Influenza A and Influenza B. China completed all clinical studies in 2011 and approved the marketing of peramivir injection in April 2013. It is the first NAI approved for intravenous use in the market and can be used in all age groups in China. During the 2009 H1N1 epidemic, the United States temporarily approved the drug for treatment in children and adults, and the patient was well tolerated [13]. In December 2014, the United States officially approved that peramivir is suitable for children 18 years of age and older, and patients with flu symptoms <2d are not available in children in the United States.
The recommended dose for children is 10mg/kg, and the single maximum dose is 600mg. It is recommended to administer a single dose. If the symptoms are severe, it can be administered continuously according to the condition, once/d, 1~5d. The drug is characterized by rapid onset and long duration of action. Studies have shown that the efficacy of a single dose of peramivir is comparable to that of oseltamivir 5d [14]. Because of intravenous administration, peramivir is suitable for use in patients with severe influenza and in children who cannot be taken orally [12]. A number of clinical studies have shown that peramivir is similar to oseltamivir phosphate against influenza virus [14,15,16]. A Japanese clinical study showed that 117 children (125d to 15 years old) were treated with peramivir for the treatment of A(H1N1) infection and adverse drug reactions were resolved or improved quickly [17].
2.2M2 ion channel blocker
M2 ion channel blockers include amantadine and rimantadine, which inhibit viral replication by blocking the ion channel of the influenza virus M2 protein. Because the influenza B virus lacks M2 membrane protein, these drugs are only used to treat influenza A and are not effective against influenza B. These drugs have many clinical adverse reactions, which can cause adverse reactions in the central nervous system, such as dizziness, anxiety, depression, headache, etc., and even hallucinations and convulsions; gastrointestinal reactions include nausea and vomiting. In addition, the amino acid mutation at position 31 of the influenza virus M2 ion channel protein caused high drug resistance [18]. Central nervous system adverse reactions and drug resistance problems limit the clinical application of this class of drugs in pediatrics [12].
2.3 Chinese medicine
During the H1N1 and H7N9 epidemics in 2009, China recommended and approved the application of some Chinese herbal medicines [19,20]. Among them, honeysuckle, forsythia, and nasturtium are common drugs used in the prevention and treatment of influenza prescriptions. Traditional Chinese medicine starts from the whole, and its role in syndrome differentiation is positive in the prevention and treatment of influenza. The combination of traditional Chinese and Western medicine for the treatment of influenza still needs to be continuously explored and gradually internationalized.
3 drug selection for preventing influenza
Although vaccination is the best way to prevent influenza virus infection, in the case of influenza outbreaks, people who cannot be used for vaccine prevention and some key children can use drug prevention. Recommended population: (1) high-risk children who cannot be vaccinated against influenza, or children with immune abnormalities and no response to vaccines; (2) high-risk children within 2 weeks of vaccination; (3) high-risk children with unimmunized or age < Family members or caregivers who are intimately contacted by infants and young children for 24 months; (4) used to control influenza outbreaks in unimmunized children or in child gathering places (such as kindergartens); (5) after exposure of family members Prevention, prevention of high-risk flu complications and close contact with influenza patients; (6) community or family outbreaks of influenza, influenza strains and vaccines do not match [12]. Both oseltamivir and zanamivir can be used for prophylaxis. For those who are eligible for prophylactic use, it is recommended to use it early (as much as possible within 48 hours of exposure), until 7 to 10 days after the last exposure; within 48 hours after exposure For drug users, prophylactic administration is still recommended [12].
4 drug selection for the treatment of influenza
For most previously healthy children, the flu is a mild and self-limiting infection that usually does not require antiviral medication. Excessive drug treatment may help the virus to develop resistance, and may increase the adverse effects of the drug itself on the body. The following conditions are suitable for anti-influenza drug treatment.
4.1 Recommended anti-influenza drugs
(1) Children with laboratory pathogens confirmed or highly suspected of influenza and who have high risk factors for complications, regardless of the underlying disease, influenza vaccine immune status and the severity of influenza, should be treated within 48 hours of onset; (2) In the laboratory confirmed or highly suspected flu hospitalized children, regardless of the underlying disease, influenza vaccine immune status, if the influenza virus test is positive after 48 hours of onset, antiviral drugs are also recommended.
4.2 Consider using anti-flu drugs
(1) High-risk factors for clinical suspicion of flu, no improvement in morbidity >48h, and influenza outpatients with positive specimens after 48h; (2) clinically highly suspected or laboratory confirmed influenza, uncomplicated risk factors, and onset < An anti-viral medication may be considered for a 48-hour visit, but an outpatient who wishes to shorten the course of the disease and thereby reduce the risk of complications, or who have a close history of exposure to high-risk influenza patients. Children with significant symptoms and persistence for >48 hours can also benefit from antiviral therapy [12].
The choice of antiviral drugs is mainly based on the characteristics and drug resistance of the drugs.
The resistance of influenza viruses is constantly changing, and the sensitivity of drugs should be based on virus monitoring results. There is resistance in oseltamivir. NAI is effective for most seasonal flu in recent years and has a certain effect on bird flu. The WHO tested the NAI resistance of 13312 strains of influenza virus collected between 2014 and 2015. The total resistance rate of all viruses to oseltamivir, zanamivir, palamivir and lanimivir was only about It is 0.5%, which is down from 1.9% in 2013-2014, close to 0.6% in 2012-2013. Drug-resistant strains may still be sensitive to other NAI when they are resistant to oseltamivir [21].
NAI treatment should be applied as soon as possible within 48 hours of the onset of flu symptoms. Oseltamivir is widely used in the treatment of adults and children. Zanamivir is intended for children and adults over 7 years of age, but not for patients with basic lung diseases such as asthma [1]. There are relatively few clinical studies on the use of peramivir in children, and limited research on drug resistance. It can be used in children of all ages in China and can be used in critically ill patients and children who cannot be orally or cannot be atomized. The M2 ion channel blocker is only effective against influenza A, but the drug resistance monitoring shows that it is almost completely resistant to type A H1N1 (2009) and type A H3N2, and has a high resistance rate to seasonal influenza in recent years, so it is not currently used. Empirical antiviral therapy for influenza [1]. Chinese medicine can be used for the treatment of mild cases or for the treatment of critically ill patients.
Original title: How to choose the flu drugs commonly used in children is related to the life of a child
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