What is the appropriate dose of amoxicillin for an 11-year-old patient weighing 43.6 kilograms?

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Last updated: February 16, 2025View editorial policy

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From the Guidelines

For an 11-year-old patient weighing 43.6kg, the recommended dose of amoxicillin is 40-90 mg/kg/day in 2-3 divided doses, with a maximum dose of 4000 mg/day 1.

Calculating the dose

Based on this guideline, the patient's dose would be approximately 1744-3914mg per day.

Suitable dosing regimens

A suitable dosing regimen would be 28.4-63.4ml of amoxicillin 400mg/5ml per day, divided into 2-3 doses, which translates to 9.5-21.1ml of amoxicillin 400mg/5ml every 8 hours, or 14.2-31.7ml every 12 hours.

Alternative dosing recommendations

Alternatively, a dose of 50 mg/kg once daily, with a maximum of 1000 mg per dose, can be considered, as recommended by 1.

  • For this patient, the dose would be approximately 2170mg per day, which is within the recommended range.
  • However, it is essential to note that the dosing frequency and regimen should be individualized based on the patient's specific needs and the severity of the infection.

Important considerations

It is crucial to consider the patient's renal function and adjust the dose accordingly, as amoxicillin is primarily excreted by the kidneys 1.

  • Additionally, the patient's weight and age should be taken into account when determining the appropriate dose, as recommended by 1 and 1.

From the FDA Drug Label

Table 1 ... Weight Less than 40 kg ... 25 mg/kg/day in divided doses every 12 hours or 20 mg/kg/day in divided doses every 8 hours ... 45 mg/kg/day in divided doses every 12 hours or 40 mg/kg/day in divided doses every 8 hours

For an 11-year-old patient weighing 43.6 kilograms, since the patient's weight is greater than 40 kg, we should refer to the adult dosing recommendations.

  • The recommended dosage for a patient over 40 kg is not explicitly stated in the provided text for the specific weight, but we can look at the dosages for adults and pediatric patients aged 3 months and older.
  • For mild/moderate infections, the recommended dosage is 500 mg every 12 hours or 250 mg every 8 hours for patients over 40 kg.
  • For severe infections, the recommended dosage is 875 mg every 12 hours or 500 mg every 8 hours for patients over 40 kg. Since the patient's weight is over 40 kg, these dosages can be considered. However, it's crucial to consult with a healthcare professional to determine the best course of treatment based on the specific infection and individual patient needs 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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