From the Guidelines
Management of a patient with influenza-like symptoms involves a comprehensive approach focusing on diagnosis, supportive care, and potential antiviral therapy, with antiviral medications such as oseltamivir considered for patients at high risk for complications if presenting within 48 hours of symptom onset 1.
Assessment and Diagnosis
The patient's symptoms, vital signs, and risk factors for complications should be assessed. Symptoms may include fever, cough, sore throat, body aches, and fatigue. Risk factors for complications include elderly, pregnant women, immunocompromised individuals, or those with chronic medical conditions.
Supportive Care
For most healthy individuals, supportive care is recommended:
- Rest
- Adequate hydration
- Over-the-counter medications like acetaminophen (500-1000mg every 6 hours, maximum 4g daily) or ibuprofen (400-600mg every 6-8 hours with food) for fever and pain relief
Antiviral Therapy
Antiviral medications such as oseltamivir (Tamiflu, 75mg twice daily for 5 days) should be considered for patients at high risk for complications if presenting within 48 hours of symptom onset. The dosage of oseltamivir varies by age and weight, as outlined in the CDC guidelines 1.
Rapid Influenza Diagnostic Tests
Rapid influenza diagnostic tests can guide treatment decisions. Patients should be advised to isolate until fever-free for 24 hours without antipyretics to prevent transmission.
Warning Signs
Warning signs requiring urgent medical attention include:
- Difficulty breathing
- Persistent chest pain
- Confusion
- Severe weakness
- Worsening of symptoms after initial improvement
Antiviral Mechanism
Antivirals work by inhibiting viral replication, reducing symptom duration and severity when started early, while supportive measures help manage symptoms and prevent dehydration while the immune system fights the infection.
Chemoprophylaxis
Chemoprophylaxis may be considered in certain situations, such as for children at high risk of complications from influenza for whom the influenza vaccine is contraindicated, or for family members or healthcare providers who are unimmunized and are likely to have ongoing, close exposure to unimmunized children at high risk or unimmunized infants and toddlers who are younger than 24 months 1.
From the FDA Drug Label
In studies of naturally acquired and experimental influenza, treatment with oseltamivir phosphate for oral suspension did not impair normal humoral antibody response to infection.
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. Eligible subjects had fever of at least 100ºF, accompanied by at least one respiratory symptom (cough, nasal symptoms, or sore throat) and at least one systemic symptom (myalgia, chills/sweats, malaise, fatigue, or headache), and influenza virus was known to be circulating in the community
Subjects were required to self-assess the influenza-associated symptoms (nasal congestion, sore throat, cough, aches, fatigue, headaches, and chills/sweats) twice daily as "none," "mild," "moderate," or "severe". Time to improvement was calculated from the time of treatment initiation to the time when all symptoms were assessed as "none" or "mild".
The management and assessment for a patient presenting with influenza-like symptoms involves:
- Monitoring symptoms: Patients should self-assess their influenza-associated symptoms, such as nasal congestion, sore throat, cough, aches, fatigue, headaches, and chills/sweats, twice daily.
- Treatment initiation: Treatment with oseltamivir phosphate should be started within 40 hours of onset of symptoms.
- Symptom evaluation: Time to improvement should be calculated from the time of treatment initiation to the time when all symptoms are assessed as "none" or "mild".
- Fever management: Patients are allowed to take fever-reducing medications.
- Dosing: Oseltamivir phosphate should be administered twice daily for 5 days at a dose of 75 mg for adults.
From the Research
Management of Influenza-Like Symptoms
The management of patients presenting with influenza-like symptoms involves the use of antiviral medications, such as oseltamivir, to reduce the duration and severity of symptoms.
- Oseltamivir has been shown to be effective in reducing the time to recovery in patients with influenza-like illness, with a median reduction in recovery time of 1-2 days 3, 4, 5.
- The efficacy of oseltamivir is highest when initiated within 12-48 hours of symptom onset, with earlier treatment resulting in shorter illness duration 5.
- Oseltamivir is generally well-tolerated, with common adverse events including nausea and vomiting, which are usually transient and mild 3, 4, 5.
Assessment of Influenza-Like Symptoms
The assessment of patients with influenza-like symptoms involves a combination of clinical evaluation and laboratory testing.
- Clinical evaluation includes assessment of symptoms such as fever, headache, and muscle ache, as well as evaluation of underlying medical conditions and risk factors for complications 3, 4.
- Laboratory testing, such as PCR or rapid antigen testing, can be used to confirm the diagnosis of influenza and guide treatment decisions 3, 6.
- The use of oseltamivir in combination with other antiviral medications, such as zanamivir, has been studied, but the evidence suggests that this combination may not be more effective than oseltamivir monotherapy 6.
Treatment Options
Treatment options for patients with influenza-like symptoms include: