Table 8.
Antiviral Agents and Dosing Recommendations for Treatment and Chemoprophylaxis of Influenza
| Antiviral Agents and Age Group | Treatment Dosing | Chemoprophylaxis Dosing |
|---|---|---|
| Oseltamivir | ||
| Adults | 75 mg twice daily | 75 mg once daily |
| Pregnancy (any trimester)a | 75 mg twice dailyb | 75 mg once dailyb |
| Children (1 year or older) ≤15 kg | 30 mg twice daily | 30 mg once daily |
| Children >15–23 kg | 45 mg twice daily | 45 mg once daily |
| Children >23–40 kg | 60 mg twice daily | 60 mg once daily |
| Children >40 kg | 75 mg twice daily | 75 mg once daily |
| Infants 9–11 months | 3.5 mg/kg per dose twice dailyc | 3.5 mg/kg per dose once dailyc |
| 3 mg/kg per dose twice dailyc | 3 mg/kg per dose once dailyc | |
| Term infants 0–8 months | 3 mg/kg per dose twice daily | 3 mg/kg per dose once daily if ≥3 months; not recommended for infants <3 months unless the situation is judged critical due to lack of safety and efficacy data |
| Preterm infants | See details in footnotea | No data |
| Zanamivir | ||
| Adults | 10 mg (two 5-mg inhalations), twice daily | 10 mg (two 5-mg inhalations), once daily |
| Children (≥7 years) | 10 mg (two 5-mg inhalations), twice daily | 10 mg (two 5-mg inhalations), once daily |
| Peramivird | ||
| Adults | 600 mg intravenous infusion once, given over 15–30 minutes | NA |
| Children (2—12 years) | One 12 mg/kg dose, up to 600 mg maximum, intravenous, given over 15–30 minutes | NA |
| Children (13–17 years) | 600 mg intravenous infusion once, given over 15–30 minutes | NA |
Antiviral resistance information is available in the weekly Centers for Disease Control and Prevention (CDC) influenza surveillance report: https://wwwcdc.gov/flu/weekly/index.htm. Abbreviation: NA, not applicable.
The weight-based dosing recommendation for preterm infants is lower than for term infants. Preterm infants may have lower clearance of oseltamivir because of immature renal function, and doses recommended for full-term infants may lead to very high drug concentrations in this age group. Limited data from the National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group provide the basis for dosing preterm infants using their postmenstrual age (ie, gestational age + chronological age): 1.0 mg/kg per dose, orally, twice daily, for those <38 weeks postmenstrual age; 1.5 mg/kg per dose, orally, twice daily, for those 38–40 weeks postmenstrual age; 3.0 mg/kg per dose, orally, twice daily, for those >40 weeks postmenstrual age. For extremely premature infants (<28 weeks), please consult a pediatric infectious diseases physician (Committee on Infectious Diseases. Recommendations for prevention and control of influenza in children, 2017–2018. Pediatrics 2018; 141. pii:e20173535).
Based on pharmacokinetic data in pregnancy, regardless of trimester, a dose of 105 mg twice daily was predicted to provide the effective exposure provided to nonpregnant adults Some experts recommend 150 mg twice daily for severe illness in pregnant women. Optimal dosing for prophylaxis in pregnant women is unknown.
The American Academy of Pediatrics recommends 3.5 mg/kg per dose twice daily; CDC and US Food and Drug Administration (FDA)-approved dosing is 3 mg/kg per dose twice daily for children aged 9–11 months.
Approved for early treatment of uncomplicated influenza in outpatients. If used off-label for treatment of hospitalized patients, repeated once-daily dosing can be considered, although data are very limited.