From the Guidelines
The recommended dose of Oseltamivir (Tamiflu) for treating influenza in adults and adolescents 13 years and older is 75 mg twice daily for 5 days, while for children, the dose is weight-based, as outlined in the most recent guidelines. For children, the dose is as follows:
- 12 mo (based on body weight):
- ≤15 kg (≤33 lb): 30 mg, twice daily
15 kg–23 kg (>33 lb–51 lb): 45 mg, twice daily
23 kg–40 kg (>51 lb–88 lb): 60 mg, twice daily
40 kg (>88 lb): 75 mg, twice daily
- Infants 9–11 mo: 3.5 mg/kg per dose, twice daily
- Term infants 0–8 mo: 3 mg/kg per dose, twice daily
- Preterm infants:
- <38 wk postmenstrual age: 1.0 mg/kg per dose, twice daily
- 38 through 40 wk postmenstrual age: 1.5 mg/kg per dose, twice daily
40 wk postmenstrual age: 3.0 mg/kg per dose, twice daily For prevention of influenza, the adult dose is 75 mg once daily for at least 10 days following exposure, as indicated in the guidelines 1. Treatment should ideally begin within 48 hours of symptom onset for maximum effectiveness, and dose adjustments are necessary for patients with severe renal impairment, as noted in the guidelines 1. Common side effects include nausea and vomiting, which can be minimized by taking the medication with food, and Tamiflu works by inhibiting the influenza virus from spreading within the body, which can shorten the duration of illness and reduce the severity of symptoms when started early in the course of infection. It's essential to follow the most recent guidelines for the use of Oseltamivir, as recommendations may change based on new evidence and clinical experience, as seen in the updates from 1, 1, and 1.
From the FDA Drug Label
2 DOSAGE AND ADMINISTRATION
2.1 Dosage and Administration Overview Administer oseltamivir phosphate for oral suspension for the treatment of influenza in patients 2 weeks of age or older [see Dosage and Administration (2.2)] or for prophylaxis of influenza in patients 1 year and older [see Dosage and Administration (2. 3)] 2. 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. Pediatric Patients (2 weeks of age through 12 years of age) Table 1 displays the recommended oral dosage of oseltamivir phosphate for oral suspension for treatment of influenza in pediatric patients 2 weeks of age through 12 years of age 2. 3 Recommended Dosage for Prophylaxis of Influenza Initiate post-exposure prophylaxis with oseltamivir phosphate for oral suspension within 48 hours following close contact with an infected individual. Initiate seasonal prophylaxis with oseltamivir phosphate for oral suspension during a community outbreak Adults and Adolescents (13 years of age and older) The recommended dosage of oseltamivir phosphate for oral suspension for prophylaxis of influenza in adults and adolescents 13 years and older is 75 mg orally once daily (12. 5 mL of oral suspension once daily) for at least 10 days following close contact with an infected individual and up to 6 weeks during a community outbreak.
The recommended dose and duration of Oseltamivir (Tamiflu) are as follows:
- Treatment of Influenza:
- Adults and adolescents (13 years and older): 75 mg twice daily for 5 days
- Pediatric patients (2 weeks to 12 years): dose varies by weight (see Table 1)
- Prophylaxis of Influenza:
- Adults and adolescents (13 years and older): 75 mg once daily for at least 10 days following close contact with an infected individual and up to 6 weeks during a community outbreak
- Pediatric patients (1 year to 12 years): dose varies by weight (see Table 1) 2
From the Research
Recommended Dose and Duration of Oseltamivir (Tamiflu)
- The recommended dose of oseltamivir for adults is 75 mg twice daily for 5 days 3.
- For children, the recommended dose is 2 mg/kg twice daily for 5 days, with unit doses of 30,45, and 60 mg oral suspension recommended for children weighing ≤15 kg, >15-23 kg, and >23-40 kg, respectively 4.
- In immunocompromised pediatric patients, a dosage recommendation of 75 mg twice daily for 10 days is established, based on extrapolation of efficacy from immunocompromised adults 5.
- In immunocompromised adult patients, the use of conventional-dose oseltamivir 75 mg twice daily for 10 days is supported 6.
- The standard-dose oseltamivir (75 mg twice daily) is recommended for enteric administration as soon as possible in critically ill patients 7.
Special Considerations
- Oseltamivir should be initiated within 36 hours of symptom onset for optimal efficacy 3.
- Treatment duration of 10 days is favored over 3-5 days to limit viral rebound in immunocompromised patients 5, 6.
- Oseltamivir is well tolerated in clinical trials, with nausea and vomiting being the most commonly reported events, which can be mitigated by taking the drug with food 3.