From the Guidelines
The influenza infection period typically lasts 5-7 days in most healthy adults, though some symptoms like cough and fatigue may persist for up to 2 weeks, as noted in studies such as 1 and 1. Management involves both limiting transmission and treating symptoms. To prevent spreading the virus, infected individuals should stay home for at least 24 hours after fever resolves without fever-reducing medications. Symptom management includes:
- Rest
- Adequate hydration
- Over-the-counter medications like acetaminophen (325-650 mg every 4-6 hours, not exceeding 3000 mg daily) or ibuprofen (200-400 mg every 4-6 hours with food) for fever and pain. Antiviral medications such as oseltamivir (Tamiflu, 75 mg twice daily for 5 days) can reduce illness duration if started within 48 hours of symptom onset, as recommended by 1 and 1. These medications work by inhibiting viral replication, while supportive care helps the immune system fight the infection. High-risk individuals, including the elderly, pregnant women, young children, and those with chronic medical conditions, should contact healthcare providers promptly as they may benefit most from early antiviral treatment and might require closer monitoring for complications, as suggested by 1 and 1.
The most recent and highest quality study, 1, provides guidance on the prevention and treatment of cancer-related infections, including influenza, and supports the use of antiviral medications like oseltamivir for the treatment of influenza. This study also highlights the importance of rapid screening tests for detection of influenza and the need for empirical antiviral therapy in patients with symptoms suggestive of influenza, especially during community outbreaks.
Overall, the management of influenza infection involves a combination of limiting transmission, treating symptoms, and using antiviral medications to reduce illness duration and prevent complications, as supported by the evidence from 1, 1, 1, and 1.
From the FDA Drug Label
In both trials, there was a 1.3-day reduction in the median time to improvement in influenza-infected subjects who received oseltamivir phosphate 75 mg twice a day for 5 days compared to subjects who received placebo.
The duration of the influenza infection period is not directly stated in the provided drug labels. However, the time to improvement in influenza-infected subjects was reduced by 1.3 days with oseltamivir phosphate treatment.
- Management of the influenza infection period includes treatment with oseltamivir phosphate 75 mg twice daily for 5 days, as well as the use of fever-reducing medications as needed 2.
- The treatment effect of oseltamivir phosphate was consistent across different populations, including adults, adolescents, and pediatric subjects 2.
From the Research
Influenza Infection Period
- The duration of influenza infection can vary, but treatment with anti-influenza drugs can decrease the duration of illness by about 24 hours in otherwise healthy patients 3.
- The benefit of treatment is greatest when antiviral therapy is started within 24 hours of symptom onset 3.
- Neuraminidase inhibitors, such as zanamivir and oseltamivir, 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 4.
- Clinical studies have shown that zanamivir and oseltamivir can reduce the duration of influenza-related symptoms by approximately 0.7-1.5 days 5.
Management of Influenza Infection
- Annual influenza vaccination is recommended for all people six months and older who do not have contraindications 3.
- Treatment with one of four approved anti-influenza drugs may be considered if the patient presents within 48 hours of symptom onset 3.
- Zanamivir and oseltamivir are effective in preventing culture-positive influenza or for treatment of culture-positive influenza in febrile individuals 5.
- The most common adverse effects of zanamivir and oseltamivir include upper respiratory tract symptoms, headaches, nausea, and vomiting 5.
- Peramivir has been shown to alleviate fever and other symptoms sooner than zanamivir, oseltamivir, and laninamivir in some studies 6.
Comparison of Anti-Influenza Drugs
- There is no significant difference in efficacy between oseltamivir and zanamivir 7.
- Temperature normalization was significantly faster in patients taking zanamivir compared to oseltamivir 7.
- Respiratory distress was observed in some patients taking zanamivir, but not in those taking oseltamivir 7.
- The appropriate use of neuraminidase inhibitors requires further study 6.