From the Guidelines
The most effective way to manage flu is through annual vaccination, and for those at high risk or with severe symptoms, antiviral medications like oseltamivir should be prescribed within 48 hours of symptom onset 1.
Diagnosis and Treatment
When diagnosing flu, it's essential to consider the patient's symptoms, such as fever and acute onset of respiratory signs and symptoms, regardless of their vaccination status 1. The following groups should be considered for diagnosis:
- Immunocompetent and immunocompromised individuals, including healthcare personnel, with fever and acute respiratory symptoms
- Individuals with fever and exacerbation of underlying chronic pulmonary disease
- Infants and young children with fever and no other symptoms
- Elderly individuals with new or worsening respiratory symptoms
Antiviral Medications
Antiviral medications can be administered within 48 hours of symptom onset for patients at high risk of complications or those who want to reduce the duration of the illness and their risk of complications 1. The recommended duration of antiviral therapy is typically 5 days.
Prevention
Prevention is key in managing flu, and annual vaccination is the primary tool in preventing influenza 1. Other preventive measures include:
- Frequent handwashing
- Avoiding close contact with sick individuals
- Covering coughs and sneezes
- Considering chemoprophylaxis for individuals at high risk of complications, such as those who cannot receive the flu vaccine
Chemoprophylaxis
Chemoprophylaxis should be considered for individuals at high risk of complications, including adults and children ≥1 year with underlying medical conditions, close contacts of high-risk individuals, and employees in institutions with influenza outbreaks 1. The duration of chemoprophylaxis depends on the individual's risk factors and the type of vaccine received.
From the FDA Drug Label
RELENZA is a prescription medicine used to: • treat the flu (influenza A and B virus) in people who are aged 7 years and older who have had flu symptoms for no more than 2 days • help prevent the flu in people who are aged 5 years and older.
The primary use of RELENZA is to treat and prevent the flu in people aged 7 years and older for treatment, and 5 years and older for prevention.
- Treatment: RELENZA is used to treat the flu in people who have had flu symptoms for no more than 2 days.
- Prevention: RELENZA is used to help prevent the flu in people who are at risk. 2
From the Research
Overview of Flu Treatment
- Influenza infection is responsible for thousands of hospitalizations and deaths in the United States each year 3.
- The treatment options for flu have expanded to include antiviral agents such as zanamivir and oseltamivir, which have been approved by the US Food and Drug Administration for the treatment of influenza A and influenza B 3.
Antiviral Agents for Flu Treatment
- There are two commonly used classes of antiviral agents approved for the prevention of and treatment for influenza: the M2 Inhibitors (amantadine and rimantadine) and the neuraminidase inhibitors (oseltamivir, laninamivir, peramivir, and zanamivir) 4.
- Zanamivir and oseltamivir inactivate viral neuraminidase, an enzyme responsible for cleaving sialic acid residues on newly formed virions as they bud off from the host cell, resulting in aggregation of virions on the surface of the host cell, which limits the extent of infection and speeds recovery from illness 3.
- Clinical studies have shown that neuraminidase inhibitors can decrease the median duration of influenza-related symptoms by approximately 1 day if initiated within 48 hours of the onset of symptoms of influenza 3.
Comparison of Efficacy and Safety of Antiviral Agents
- A study comparing the efficacy and safety of oseltamivir and zanamivir in the treatment of influenza found that there was no significant difference in efficacy between the two drugs, but temperature normalization was significantly faster in patients taking zanamivir 5.
- Another study found that inhaled zanamivir is not inferior to oral oseltamivir in preventing influenza-related hospitalization or death for patients whose conditions do not require hospitalization within 2 days 6.
- A study comparing the clinical effects of oseltamivir, zanamivir, laninamivir, and peramivir on seasonal influenza infection in outpatients in Japan found that the ability of each antiviral agent to alleviate influenza symptoms and fever varied, with peramivir alleviating fever and other symptoms sooner than the other three antiviral agents 7.