What is the appropriate Oseltamivir (Tamiflu) dosing for a child weighing 35 pounds?

From the Guidelines

For a 35 lb (approximately 16 kg) child, the recommended Tamiflu (oseltamivir) dose is 45 mg twice daily for 5 days for treatment of influenza, as stated in the most recent guidelines 1. This dose is based on the child's weight, as Tamiflu dosing for children is 30 mg twice daily for those weighing less than 15 kg, 45 mg twice daily for those weighing 15-23 kg, and 60 mg twice daily for those weighing 23-40 kg. Some key points to consider when administering Tamiflu to children include:

• Tamiflu comes as a liquid suspension (6 mg/mL) or capsules (30 mg, 45 mg, and 75 mg), so the 45 mg dose would be 7.5 mL of the suspension or one 45 mg capsule twice daily.
• Tamiflu works best when started within 48 hours of symptom onset, as it inhibits the viral neuraminidase enzyme, preventing the release of new virus particles from infected cells.
• Common side effects include nausea and vomiting, which may be reduced by taking the medication with food.
• If using for prevention after exposure to influenza, the same dose would be given once daily for 10 days, as recommended by the Centers for Disease Control and Prevention 1. It's essential to follow the recommended dosage and administration guidelines to ensure the effectiveness of the treatment and minimize potential side effects.

From the FDA Drug Label

Table 1 Oseltamivir Phosphate for Oral Suspension Dosage Recommendations in Pediatric Patients for Treatment and Prophylaxis of Influenza Weight Treatment Dosage for 5 days Prophylaxis Dosage for 10 days* Volume of OralSuspension(6 mg/mL) for each Dose† Number of Bottles of OralSuspensionto Dispense Patients from 2 Weeks to less than 1 Year of Age Any weight 3 mg/kg twicedaily Not applicable 0. 5 mL/kg§ 1 bottle Patients 1 to 12 Years of Age Based on Body Weight 15 kg or less 30 mg twicedaily 30 mg oncedaily 5 mL 1 bottle 15.1 kg to 23 kg 45 mg twicedaily 45 mg oncedaily 7.5 mL 2 botles 23.1 kg to 40 kg 60 mg twicedaily 60 mg oncedaily 10 mL 2 bottles 40.1 kg or more 75 mg twicedaily 75 mg oncedaily 12. 5 mL 3 bottles

For a child weighing 35 pounds, first convert the weight to kilograms: 35 pounds is approximately 15.9 kg. Based on the weight, the recommended dosage is for the weight range of 15.1 kg to 23 kg. The recommended treatment dosage is 45 mg twice daily and the recommended prophylaxis dosage is 45 mg once daily. The volume of oral suspension for each dose is 7.5 mL. 2

From the Research

Oseltamivir Dosing for Children

To determine the appropriate Oseltamivir (Tamiflu) dosing for a child weighing 35 pounds, we need to consider the available evidence.

• The dosing of Oseltamivir for children is typically based on their weight, with a recommended dose of 2 mg/kg twice daily for 5 days 3.
• However, none of the provided studies directly address the specific dosing for a child weighing 35 pounds.
• A study on oseltamivir pharmacokinetics mentions that the drug is suitable for use in diverse patient populations, including young children 4.
• Another study discusses the use of oseltamivir outside of labeled recommendations, but does not provide specific guidance on dosing for children based on weight 5.
• A review of oseltamivir dosing recommendations suggests that current guidelines may not be optimal for patients with mild to moderate renal impairment or large body mass, but does not provide specific guidance for children 6.
• A study on baloxavir marboxil, a different antiviral medication, mentions the use of oseltamivir as a comparator, but does not provide information on oseltamivir dosing for children based on weight 7.

Calculation of Oseltamivir Dosing

Based on the available evidence, we can calculate the recommended dose for a child weighing 35 pounds (approximately 15.9 kg) as follows:

• 2 mg/kg twice daily for 5 days
• For a child weighing 15.9 kg, the recommended dose would be:
  • 2 mg/kg x 15.9 kg = 31.8 mg twice daily
• However, please note that this calculation is based on a study that does not directly address the specific dosing for a child weighing 35 pounds, and the actual recommended dose may vary depending on the specific clinical guidelines and recommendations.