Flu Treatment Info

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Flu season is well under way in many parts of Texas. Given this early start, and considering the mild flu season experienced last winter, experts believe we may experience higher influenza activity with a higher number of cases this year. Providers from around the state are seeing cases of laboratory confirmed influenza A and B virus infection – and some children’s hospitals are starting to report hospitalizations and deaths from influenza.

Initial testing of circulating strains by the CDC indicates a good match with the 2012-13 influenza vaccine. Vaccination is the best method of prevention of influenza; however, understanding treatment guidelines is imperative for providing care to patients exhibiting flu-like symptoms.

The AAP recommends treatment with influenza antivirals in all children who are hospitalized, children at risk of complications from the flu, children with complicated or progressive illness, and in anyone who want to shorten their illness. In outpatients without risk factors for complications, antiviral treatment should be considered if treatment can be initiated within 48 hours of symptom onset. The following are some suggestions from the TPS Committee on Infectious Diseases and Immunizations on treating influenza:

Treatment
Antiviral treatment for influenza is most effective if started early, with the greatest benefit seen when providing antiviral medication within the first 2 days of illness. However, there may still be some benefit to treatment when started after 48 hours of onset of symptoms, particularly in more severe cases that result in hospitalization.  Antiviral treatment can be started when patients present with flu-like symptoms and flu is suspected. You do not need to wait for laboratory confirmation of influenza to start treatment.

Use of Anti-viral Medications
The neuraminidase inhibitors, Oseltamivir (administered orally) and Zanamavir (administered through inhalation) are at present the preferred antiviral agents to treat influenza. Oral oseltamivir is safe and effective, but it may cause nausea and vomiting in some children.  Allergic reactions and other reported side effects are rare.  Resistance to oseltamivir is very rare (<2%) and is not associated with the use of the drug. Zanamavir is safe and effective, but requires understanding of the use of the device to administer the dose through oral inhalation. Treatment and prophylactic dosing recommendations for these antivirals in children is described below. 

Treatment in Children Under 1 Year of Age
On December 21, 2012, the U.S. Food and Drug Administration expanded the approved use of oseltamivir to treat children as young as 2 weeks old who have shown symptoms of flu for no longer than two days. The AAP, CDC, and other experts recommend treatment for children under one year old, as they have the highest risk of complications. Although there is a fixed dosing regimen for patients 1 year and older according to weight categories, the dosing for children younger than 1 year must be calculated for each patient based on their exact weight. These children should receive 3 milligrams per kilogram twice daily for five days. These smaller doses will require a different dispenser than what is currently co-packaged with Tamiflu. Dosing recommendations are based on clinical and pharmacokinetic studies

Current Dosing for Children
Tamiflu®, or Oseltamivir, is available as:
     30, 45, and 75 mg capsules
     6 mg/ml and 12 mg/ml suspension

Age/Weight

Treatment x 5 days
Approved for children > 1 yr

Prophylaxis x 10 days
Approved for children > 1 yr

 < 3 months

 3mg/kg/dose bid

 Not recommended

 3-11 months

 3mg/kg/dose bid

 3mg/kg/dose qd

 1 Year and Older

 < 15 kg

 30 mg po bid

 30 mg po qd

 16 – 23 kg

 45 mg po bid

 45 mg po qd

 24 – 40 kg

 60 mg po bid

 60 mg po qd

 >40 kg

 75 mg po bid

 75 mg po qd

 

Relenza®, or Zanamivir, recommended dosing:

 Approved for children > 7yrs old  10 mg (2 inhalations) twice daily
 Approved for children > 5 years old  10 mg (2 inhalations) once daily

 

References