2018 Influenza Antiviral Recommendations
Flu Vaccine Helps Reduce Flu Symptoms
The flu season is in full swing in many parts of the country and is expected to rise in the next coming weeks! Even if the vaccine is less effective on the most common strain of flu this season, it is not too late to get your flu shot to protect yourself and your loved ones!
It is important to remember that treatment options are available and should be administered promptly, especially to high-risk patients. The following high-risk patients are at greater risk of developing flu complications:
- Pregnant women
- Adults age 65 and older
- Children age 2 and younger
- People with underlying health conditions, such as immunosuppression, asthma, diabetes, or heart disease
When administered early, antiviral treatment can:
- Lessen illness severity
- Shorten the duration of illness
- Reduce serious flu-related complications, such as pneumonia in outpatients and death in hospitalized patients
Flu Treatment and Chemoprophylaxis: from the CDC and the literature
Three influenza antiviral medications approved by the FDA are recommended for use during the 2017-2018 influenza season. It is evident that the majority of recently circulating influenza viruses are susceptible to these 3 medications, including 100% susceptibility thus far in the US to influenza A (H3N2).
1. oral oseltamivir (as generic or Tamiflu)
Oseltamivir can be used with patients of any age for treatment, and age > 3 months for prophylaxis. Adult dose is 75 mg bid for 5 days and should be started within 48 hours of symptom onset. Pediatric dose is weight-based. Side effects can include nausea, vomiting, and headache. Post marketing reports of serious skin reactions and sporadic, transient neuropsychiatric events.
2. inhaled zanamivir (Relenza)
Zanamivir can be used for patients age > 7 for treatment, and age > 5 for chemoprophylaxis. Dose is 2 puffs q 12 hours for 5 days and should be started within 48 hours of symptom onset. Contraindications include those with COPD or asthma. Side effects include risk of bronchospasm, especially in the setting of underlying airways disease; sinusitis, dizziness, and ear, nose and throat infections. Post marketing reports of sporadic, transient neuropsychiatric events
3. intravenous peramivir(Rapivab)
Flu Vaccine Recommendations
- Amantadine and rimantadine are not recommended for treatment or prophylaxis of currently circulating influenza A viruses due to high levels of resistance.
- Antiviral treatment might still provide some benefit in hospitalized patients even when begun after 48 hours of illness onset.
- Consider antiviral treatment on the basis of clinical judgment for previously healthy outpatients with confirmed or suspected influenza, even if they are not considered high risk, if treatment can be initiated within 48 hours of illness onset.
- CDC does not recommend widespread or routine use of antiviral medications for chemoprophylaxis except as one of multiple interventions to control institutional influenza outbreaks. Routine use of post-exposure chemoprophylaxis is not recommended; one reason for this is to avoid sub-therapeutic treatment dosing if infection is already established.
Antiviral medications are approximately 70-90% effective in preventing influenza and are useful adjuncts to influenza vaccination.
- Antiviral medications can be considered for chemoprophylaxis to prevent influenza in certain situations, such as the following examples:
Prevention of influenza in persons at high risk of influenza complications during the first two weeks following vaccination after influenza exposure.
Prevention for people at high risk for complications from influenza who cannot receive influenza vaccine due to a contraindication after influenza exposure.
Prevention for people with severe immune deficiencies or others who might not respond to influenza vaccination, such as persons receiving immunosuppressive medications, after influenza exposure.
- An emphasis on close monitoring and early initiation of antiviral treatment if fever and/or respiratory symptoms develop is an alternative to chemoprophylaxis after a suspected exposure for some persons.
- To be effective as chemoprophylaxis, an antiviral medication must be taken each day for the duration of potential exposure to a person with influenza and continued for 7 days after the last known exposure.
- Chemoprophylaxis generally is not recommended if more than 48 hours have elapsed since the first influenza exposure.
- Patients receiving chemoprophylaxis should be encouraged to seek medical evaluation immediately if they develop a febrile illness that might indicate influenza.
- Stewart RJ et al. Influenza antiviral prescribing for outpatients with an acute respiratory illness and at high risk for influenza-associated complications during five influenza seasons—United States, 2011-2016. Clin Infect Dis. 2017 Oct 23.
- CDC Influenza Antiviral Medications Summary
- US Influenza Weekly Surveillance Report