From the Guidelines
Tamiflu (oseltamivir) should be prescribed at a dose of 75 mg twice daily for 5 days for adults and adolescents with influenza, while children should receive weight-based dosing, with those weighing more than 40 kg receiving the adult dose, and those weighing less receiving adjusted doses (30-60 mg twice daily depending on weight) 1.
Key Considerations
- The treatment should ideally begin within 48 hours of symptom onset for maximum effectiveness.
- For prevention after exposure, the adult dose is 75 mg once daily for 10 days.
- Patients with kidney problems may need reduced doses, with a recommended dose of 75 mg once daily for 5 days for treatment, and 30 mg once daily for 10 days for chemoprophylaxis in patients with creatinine clearance 10–30 mL/min 1.
- Common side effects include nausea and vomiting, which can be minimized by taking the medication with food.
Dosage Recommendations
- For children aged 1 year and older, the dosing is weight-based: + Children weighing ≤15 kg: 30 mg twice daily for treatment, and 30 mg once daily for chemoprophylaxis. + Children weighing >15 kg and up to 23 kg: 45 mg twice daily for treatment, and 45 mg once daily for chemoprophylaxis. + Children weighing >23 kg and up to 40 kg: 60 mg twice daily for treatment, and 60 mg once daily for chemoprophylaxis. + Children weighing >40 kg: 75 mg twice daily for treatment, and 75 mg once daily for chemoprophylaxis 1.
Special Populations
- Preterm infants: the weight-based dosing recommendation is lower than for term infants, with a recommended dose of 1.0 mg/kg per dose, twice daily, for preterm infants <38 weeks' postmenstrual age, and 3.0 mg/kg per dose, twice daily, for preterm infants ≥40 weeks' postmenstrual age 1.
- Patients with renal insufficiency: the dose should be adjusted on the basis of creatinine clearance, with a recommended dose of 75 mg once daily for 5 days for treatment, and 30 mg once daily for 10 days for chemoprophylaxis in patients with creatinine clearance 10–30 mL/min 1.
From the FDA Drug Label
2 DOSAGE AND ADMINISTRATION
- 2 Recommended Dosage for Treatment of Influenza Initiate treatment with oseltamivir phosphate for oral suspension within 48 hours of influenza symptom onset. Adults and Adolescents (13 years of age and older) The recommended oral dosage of oseltamivir phosphate for oral suspension for treatment of influenza in adults and adolescents 13 years and older is 75 mg twice daily (12. 5 mL of oral suspension twice daily) for 5 days.
The recommended dose of oseltamivir (Tamiflu) for influenza treatment is:
- 75 mg twice daily for adults and adolescents (13 years of age and older) for 5 days.
- For pediatric patients (2 weeks of age through 12 years of age), the dose is based on weight, as shown in Table 1 2. Key points:
- The dose should be initiated within 48 hours of influenza symptom onset.
- The treatment duration is 5 days.
From the Research
Oseltamivir Dosing for Influenza
- The recommended dosage of oseltamivir for the treatment of influenza is 75 mg twice daily for 5 days 3.
- A liquid formulation of oseltamivir (2 mg/kg twice daily for 5 days) has been shown to be effective in the treatment of children with influenza 3.
- For immunocompromised adult patients, a dose of 75 mg twice daily for 10 days is recommended 4.
- There is no significant benefit in doubling the dose of oseltamivir or extending treatment beyond 5 days in most patient populations 5.
Special Considerations
- In geriatric patients, oseltamivir has the most abundant evidence for reducing mortality and complications, and is recommended for use in this population 6.
- For patients who require ICU admission, oseltamivir may increase survival when used within 5 days of symptom onset 5.
- The use of oseltamivir in pediatric and high-risk patients requires further study to clarify its utility and tolerability 7.