What is the treatment for prolonged influenza (flu) symptoms?

From the Guidelines

If you're experiencing prolonged influenza symptoms, you should seek medical attention immediately, especially if symptoms have lasted more than 7-10 days or are worsening, and antiviral medications like oseltamivir (Tamiflu) may be prescribed, typically 75mg twice daily for 5 days, as recommended by the most recent guidelines 1.

Treatment Recommendations

The treatment for prolonged influenza symptoms should prioritize antiviral medications, as they have been shown to reduce the duration of illness and the risk of complications, especially when started within 48 hours of symptom onset 1.

• Oseltamivir is recommended for treatment of influenza in adults and children, with dosages varying based on age and weight, as outlined in the guidelines 1.
• For adults, the recommended dosage is 75mg twice daily for 5 days, while for children, the dosage is based on weight, ranging from 30mg to 75mg twice daily for 5 days 1.
• Zanamivir is also an option, but it is not recommended for people with chronic respiratory diseases, such as asthma or chronic obstructive pulmonary disease, due to the risk of bronchospasm 1.

Symptom Relief

In addition to antiviral medications, symptom relief is crucial for managing prolonged influenza symptoms.

• Acetaminophen (Tylenol) 650mg every 6 hours or ibuprofen (Advil) 400mg every 6 hours can be taken for fever and pain relief.
• Staying hydrated with at least 2-3 liters of fluids daily and getting plenty of rest is essential for recovery.
• Saline nasal sprays and humidifiers can help alleviate congestion, while persistent cough can be managed with dextromethorphan-containing cough suppressants and honey in warm tea.

Complications and High-Risk Groups

Prolonged symptoms may indicate complications like secondary bacterial infections or that the condition isn't influenza.

• If you have underlying conditions like asthma, heart disease, or are immunocompromised, you should seek medical care promptly as you're at higher risk for complications 1.
• Influenza typically resolves within 1-2 weeks as your immune system clears the viral infection, but fatigue may persist longer.

From the FDA Drug Label

Oseltamivir phosphate for oral suspension is indicated for the treatment of acute, uncomplicated illness due to influenza A and B infection in patients 2 weeks of age and older who have been symptomatic for no more than 48 hours. Initiate treatment with oseltamivir phosphate for oral suspension within 48 hours of influenza symptom onset. The recommended oral dosage of oseltamivir phosphate for oral suspension for treatment of influenza in adults and adolescents 13 years and older is 75 mg twice daily for 5 days.

The treatment for prolonged influenza symptoms is not directly addressed in the provided drug labels. Oseltamivir and zanamivir are only recommended for treatment of influenza symptoms that have lasted no more than 48 hours for oseltamivir and no more than 2 days for zanamivir. Therefore, the FDA drug label does not provide guidance on the treatment of prolonged influenza symptoms. 2 3

From the Research

Treatment Options for Prolonged Influenza Symptoms

• The treatment for prolonged influenza symptoms typically involves the use of anti-influenza drugs, such as oseltamivir and zanamivir, which can decrease the duration of illness by about 24 hours in otherwise healthy patients 4.
• These drugs work by inhibiting the viral neuraminidase enzyme, which is responsible for cleaving sialic acid residues on newly formed virions, thereby limiting the extent of infection and speeding recovery from illness 5, 6.
• 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 5, 6.
• The benefit of treatment is greatest when antiviral therapy is started within 24 hours of symptom onset 4.
• Inhaled zanamivir and oral oseltamivir have been shown to be effective in preventing influenza-related hospitalization or death, with no significant difference in risk between the two treatments 7.
• Oseltamivir and zanamivir have also been shown to be effective in preventing symptomatic laboratory-confirmed influenza in seasonal prophylaxis and post-exposure prophylaxis, with a relatively low proportion of subjects experiencing drug-related adverse events 8.

Effectiveness of Treatment

• The effectiveness of treatment with oseltamivir and zanamivir is greatest when initiated within 30 hours of symptom onset in febrile individuals 6.
• Treatment is more effective in preventing culture-positive influenza or for treatment of culture-positive influenza in febrile individuals 6.
• The clinical efficacy of oseltamivir and zanamivir is closer to 60-70% when used to treat laboratory-confirmed influenza, with symptom reduction of approximately 0.7-1.5 days 6.

High-Risk Subgroups

• Inhaled zanamivir is not inferior to oral oseltamivir in patients aged ≥65 years or patients with chronic lung diseases 7.
• Oseltamivir and zanamivir have been shown to be effective in preventing symptomatic laboratory-confirmed influenza in at-risk elderly subjects and in post-exposure prophylaxis within households of mixed composition 8.