What are the treatment options for Influenza (flu) in adults?

From the Guidelines

Adults with influenza should be treated with antiviral medications as soon as possible, especially if they are at high risk of complications, hospitalized, or have severe or progressive illness, as recommended by the Infectious Diseases Society of America (1). The treatment options for influenza in adults include:

• Rest and hydration to manage symptoms
• Over-the-counter medications such as:
  • Acetaminophen (Tylenol) 650mg every 6 hours or ibuprofen (Advil, Motrin) 400mg every 6 hours to reduce fever and relieve body aches
  • Decongestants like pseudoephedrine (Sudafed) 30-60mg every 4-6 hours to help with nasal congestion
  • Antihistamines such as diphenhydramine (Benadryl) 25-50mg every 6 hours to reduce runny nose and sneezing
• Prescription antiviral medications like oseltamivir (Tamiflu) 75mg twice daily for 5 days, which can shorten illness duration if started within 48 hours of symptom onset (1) It is essential to stay home for at least 24 hours after the fever subsides to prevent spreading the virus and to drink plenty of fluids to prevent dehydration. A humidifier can also be used to ease congestion. The decision to treat with antiviral medications should be based on the individual's risk factors, disease severity, and time since symptom onset, rather than waiting for a definitive influenza test result (1). Seek medical attention if you experience difficulty breathing, persistent high fever, chest pain, or if symptoms worsen after initial improvement.

From the FDA Drug Label

14 CLINICAL STUDIES 14.1 Treatment of Influenza Adults

Two randomized, placebo-controlled, double-blind clinical trials of oseltamivir phosphate were conducted in adults between 18 and 65 years old, one in the U.S. and one outside the U.S., for the treatment of acute uncomplicated influenza.

1 INDICATIONS AND USAGE 1.1 Treatment of Influenza

RELENZA (zanamivir) inhalation powder is indicated for treatment of uncomplicated acute illness due to influenza A and B virus in adults and pediatric patients aged 7 years and older who have been symptomatic for no more than 2 days.

The treatment options for Influenza (flu) in adults include:

• Oseltamivir (PO): indicated for the treatment of acute uncomplicated influenza in adults between 18 and 65 years old 2
• Zanamivir (INH): indicated for the treatment of uncomplicated acute illness due to influenza A and B virus in adults who have been symptomatic for no more than 2 days 3

From the Research

Treatment Options for Influenza in Adults

The treatment options for influenza in adults include:

• Neuraminidase inhibitors (NAIs) such as oseltamivir and zanamivir, which are the treatment of choice for influenza due to widespread resistance to the adamantanes 4, 5
• NAIs are efficacious for the treatment of influenza in ambulatory patients with mild illness, when initiated within 48 hours of symptom onset 4, 6
• Early treatment with NAIs has been shown to reduce otitis media in children, and lower respiratory tract complications, resulting in antibiotic therapy, in adults 4
• NAIs can be considered in previously healthy patients when therapy can be initiated within 48 hours of symptom onset, but the therapeutic efficacy of oseltamivir is time-dependent, with maximal benefit observed when therapy is initiated within 48 hours of symptom onset 4, 6

Special Considerations

• In patients at high risk of influenza-related complications, such as pregnant women, hospitalised patients, and patients with severe or progressive disease, NAIs should be initiated as soon as possible 4
• In patients with severe influenza, oseltamivir-resistant virus has been widely reported, and zanamivir-resistant influenza virus is rare, making inhaled or intravenous zanamivir the treatment of choice in proven or suspected oseltamivir-resistant virus 4
• Intubated patients with severe influenza can be treated with oseltamivir (suspension) administered via nasogastric tube, but the commercial dry powder formulation of zanamivir should not be administered via nebulisation due to concerns about ventilator malfunction and mortality 4

Efficacy and Safety of Antiviral Drugs

• The efficacy of antiviral drugs in preventing complications of influenza has not been consistently demonstrated, and their use should be limited to situations where a major potential benefit exists 7, 6
• Antiviral drugs have different profiles of adverse effects and drug interactions, and their use should be carefully considered in individual patients 7, 6
• The use of amantadine and rimantadine should be discouraged due to their low effectiveness and potential for adverse effects 6