Treatment for Influenza A

Recommended Dosing and Treatment

The American Academy of Pediatrics recommends oseltamivir 75 mg orally twice daily for 5 days for adults and adolescents ≥13 years 1
Treatment with oseltamivir reduces illness duration by approximately 24 hours and may decrease hospitalization rates and need for subsequent antibiotics 2
For pediatric patients ≥12 months, the recommended dose is weight-based, with doses ranging from 30 mg twice daily for ≤15 kg to 75 mg twice daily for >40 kg 3
For infants <12 months, the recommended dose is 3.5 mg/kg per dose twice daily for 9-11 months and 3 mg/kg per dose twice daily for 0-8 months 4
For preterm infants, the recommended dose is 1.0 mg/kg twice daily for <38 weeks postmenstrual age, 1.5 mg/kg twice daily for 38-40 weeks postmenstrual age, and 3.0 mg/kg twice daily for >40 weeks postmenstrual age 5

Zanamivir (inhaled) is an alternative treatment, with a recommended dose of 10 mg (two 5-mg inhalations) twice daily for 5 days, approved for ages ≥7 years 6
Peramivir (IV) is recommended for severely ill patients with concerns about oral absorption 3
Amantadine and rimantadine are not recommended due to high resistance rates among current influenza A strains 1

The standard treatment duration is 5 days 1
Longer duration may be considered for patients with persistent fever after 6 days, immunocompromised patients, or critically ill patients 3

Post-exposure prophylaxis with oseltamivir is recommended at a dose of 75 mg once daily for 10 days, initiated within 48 hours of exposure 1
Seasonal prophylaxis with oseltamivir is recommended at a dose of 75 mg once daily for up to 6 weeks during community outbreaks 7

Hospitalized patients with confirmed or suspected influenza should be started on oseltamivir immediately, regardless of symptom duration, as recommended by the Centers for Disease Control and Prevention 8
Patients with severe, progressive, or complicated illness, such as pneumonia or respiratory failure, should receive immediate antiviral treatment, as per the guidelines from the Centers for Disease Control and Prevention 8
High-risk patients, including children under 2 years, adults 65 years and older, pregnant and postpartum women, immunocompromised patients, and those with chronic conditions, should be treated promptly, according to the Centers for Disease Control and Prevention 8

For patients with creatinine clearance less than 30 mL/min, the oseltamivir dose should be reduced by 50% to 75 mg once daily, as recommended by the Infectious Diseases Society of America 9, 10

Previously healthy adults with acute bronchitis do not require routine antibiotics, but should be considered for antibiotics if worsening symptoms develop, as suggested by the Infectious Diseases Society of America 9, 10
High-risk patients with lower respiratory features should receive antibiotics, such as co-amoxiclav or tetracycline, as recommended by the Infectious Diseases Society of America 9, 10
For non-severe influenza-related pneumonia, oral co-amoxiclav or tetracycline is preferred, and should be administered within 4 hours of admission, as suggested by the Infectious Diseases Society of America 9, 10
For severe influenza-related pneumonia, IV combination therapy with a broad-spectrum β-lactamase stable antibiotic and a macrolide is recommended, as per the guidelines from the Infectious Diseases Society of America 9, 10

The Centers for Disease Control and Prevention recommends that treatment should be started empirically without waiting for laboratory confirmation in high-risk groups, including children <2 years, adults ≥65 years, pregnant and postpartum women, immunocompromised patients, and patients with chronic conditions, as stated in the Morbidity and Mortality Weekly Report 11
The American Academy of Pediatrics and other guideline societies support the initiation of treatment as soon as possible, ideally within 48 hours of symptom onset, to reduce illness duration and severity, with the greatest benefit occurring when treatment is initiated within 12-36 hours 11
For hospitalized patients, severely ill patients, or high-risk groups, treatment should be initiated even beyond 48 hours as it may still provide mortality benefit, according to the Morbidity and Mortality Weekly Report 11

Oseltamivir treatment reduces illness duration by 1-1.5 days and illness severity by up to 38%, and may decrease hospitalization rates and need for subsequent antibiotics, as reported in the Morbidity and Mortality Weekly Report 11

Patients with chronic cardiopulmonary disease, such as COPD, asthma, coronary artery disease, or heart failure, should receive oseltamivir, as recommended by the Infectious Diseases Society of America 12