Recommended treatment options for influenza primarily involve supportive care and the selective use of antiviral agents depending on patient risk factors and timing of treatment initiation. Supportive care includes advising patients to maintain adequate hydration, use paracetamol or ibuprofen for symptomatic relief, rest if fatigued, and to stay off work or school if feeling unwell. Patients should be informed about symptom duration and when to seek medical advice for complications such as pneumonia NICE CKS.
Antiviral treatment is recommended for people with confirmed or suspected influenza who are at higher risk of complications, including those aged over 65 years, children under 6 months, pregnant women, and people with chronic or immunosuppressive conditions, ideally within 48 hours of symptom onset (36 hours for zanamivir in children). Oseltamivir (oral) is the first-line antiviral for most cases, while inhaled zanamivir is preferred for severely immunosuppressed patients infected with influenza strains at high risk for oseltamivir resistance, such as influenza A(H1N1). Treatment decisions should also consider circulating influenza strains and their resistance profiles NICE CKS.
For previously healthy individuals at serious risk of complications, antiviral treatment with oseltamivir may also be considered if started early after symptom onset. Post-exposure prophylaxis with antivirals may be used in certain high-risk exposures NICE CKS.
Antiviral agents, particularly neuraminidase inhibitors like oseltamivir and zanamivir, have been shown to modestly reduce the duration of symptoms in adults but have limited impact in asthmatic children. They do not significantly reduce hospitalizations in uncomplicated cases but may be valuable for severe or complicated influenza, especially in hospital settings NICE CKS Uyeki et al. 2019. The risk of adverse effects (e.g., nausea, vomiting) should be considered when prescribing these drugs Uyeki et al. 2019, O'Sullivan et al. 2020.
Given the limitations of antivirals, vaccination remains a key preventive measure but not a treatment NICE NG103. Clinical judgement and specialist advice are advised when using antivirals, particularly in immunocompromised patients or in the context of resistant strains NICE CKS.
Key References
- CKS - Influenza - seasonal
- NG103 - Flu vaccination: increasing uptake
- NG237 - Suspected acute respiratory infection in over 16s: assessment at first presentation and initial management
- (Uyeki et al., 2019): Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa.
- (O'Sullivan et al., 2020): Influenza management with new therapies.
- (Westin et al., 2023): Management of influenza - updated Swedish guidelines for antiviral treatment.