From the Guidelines
For a 21-pound (approximately 9.5 kg) infant with otitis media, the recommended dose of amoxicillin is 80-90 mg/kg/day divided into two doses, as stated in the most recent guideline 1. This translates to approximately 760-855 mg per day, which can be divided into two doses of approximately 380-428 mg twice daily. Standard amoxicillin suspension typically comes as 250 mg/5 mL or 400 mg/5 mL. Using the 400 mg/5 mL suspension, you would give about 4.75-5.35 mL twice daily, but to simplify administration, you could round this to about 5 mL twice daily for 10 days. Ensure the full course is completed even if symptoms improve within a few days. Amoxicillin is the first-line treatment for otitis media because it effectively targets Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, the most common bacterial causes of ear infections, as supported by 1 and 1. The medication should be given with or without food, though taking it with food may help reduce stomach upset. Watch for signs of allergic reaction such as rash or difficulty breathing, and contact a healthcare provider if the infant's symptoms worsen or don't improve after 48-72 hours of treatment, as this might indicate resistance requiring a different antibiotic. Key considerations for treatment include the effectiveness of amoxicillin against common pathogens, its safety profile, and its narrow microbiologic spectrum, making it a preferred choice for initial treatment, as outlined in 1.
From the Research
Amoxicillin Dosage for a 21-Pound Infant with Otitis Media
To determine the appropriate dosage of amoxicillin for a 21-pound infant with otitis media, we need to consider the standard dosage recommendations.
- The standard dose of amoxicillin for children with acute otitis media is 40-45 mg/kg/d or 80-90 mg/kg/d for high-dose therapy 2.
- Since the infant weighs 21 pounds, we need to convert this weight to kilograms. 1 pound is approximately equal to 0.45 kilograms, so 21 pounds is approximately 9.5 kilograms.
- Using the standard dose of 40-45 mg/kg/d, the recommended dose for a 9.5 kg infant would be approximately 380-427.5 mg per day, divided into two or three doses.
- For high-dose therapy, the recommended dose would be approximately 760-855 mg per day, divided into two or three doses.
Comparison of Amoxicillin with Other Antibiotics
Several studies have compared the efficacy of amoxicillin with other antibiotics in the treatment of acute otitis media.
- A study comparing clarithromycin and amoxicillin suspensions found that both antibiotics had similar clinical success rates 3.
- Another study found that high-dose amoxicillin did not have a significant benefit over standard-dose amoxicillin in children with acute otitis media who were at low risk for infection with antibiotic-resistant bacteria 2.
- A meta-analysis found that macrolide antibiotics, such as azithromycin and clarithromycin, were associated with an increased risk of clinical failure compared to amoxicillin or amoxicillin/clavulanate 4.
- A population-based study found that azithromycin was associated with a decreased risk of failure overall, but an increased risk of failure during the first few days of treatment 5.