What is the maximum daily dose of Amoxil (amoxicillin)?

Maximum Daily Dose of Amoxicillin

The maximum daily dose of amoxicillin for adults is 4 grams per day, divided into multiple doses. 1, 2

Adult Dosing Guidelines

• The standard adult dosing regimen for amoxicillin varies based on the severity and type of infection:

  • For mild to moderate infections: 500 mg every 12 hours or 250 mg every 8 hours 1
  • For severe infections: 875 mg every 12 hours or 500 mg every 8 hours 1
  • For H. pylori infection: 1 gram twice daily (as part of triple therapy) or 1 gram three times daily (as part of dual therapy) 1

• When treating respiratory tract infections with resistant pathogens, high-dose amoxicillin (defined as 4 g/day) may be required 2

• For combination therapy with clavulanic acid, high-dose amoxicillin/clavulanate is defined as 4 g of amoxicillin with 250 mg of clavulanate per day 2

Pediatric Dosing Guidelines

• For children weighing less than 40 kg, dosing is weight-based:

  • Mild to moderate infections: 25 mg/kg/day divided every 12 hours or 20 mg/kg/day divided every 8 hours 1
  • Severe infections: 45 mg/kg/day divided every 12 hours or 40 mg/kg/day divided every 8 hours 1
  • For respiratory tract infections: 45 mg/kg/day divided every 12 hours or 40 mg/kg/day divided every 8 hours 1

• For children with high risk of resistant organisms, dosing may be increased to 80-90 mg/kg/day of the amoxicillin component (maximum 2g per dose) 3, 4

• For infants less than 12 weeks (3 months) old, the maximum recommended dose is 30 mg/kg/day divided every 12 hours due to incompletely developed renal function 1

Special Considerations

• For patients with severe renal impairment (GFR 10-30 mL/min), dose should be reduced to 500 mg or 250 mg every 12 hours, depending on infection severity 1

• For patients with very severe renal impairment (GFR less than 10 mL/min), dose should be reduced to 500 mg or 250 mg every 24 hours 1

• Hemodialysis patients should receive an additional dose both during and at the end of dialysis 1

Common Pitfalls and Considerations

• Exceeding the maximum adult dose of 4 grams per day is not recommended, even when weight-based calculations in larger children or adolescents would suggest higher doses 2, 5

• Gastrointestinal tolerability rather than toxicity often determines the upper limit of amoxicillin dosing 2

• Taking amoxicillin at the start of a meal can minimize potential gastrointestinal intolerance 1

• When treating infections caused by Streptococcus pyogenes, a minimum of 10 days of treatment is recommended to prevent acute rheumatic fever 1

• For most infections, treatment should continue for at least 48-72 hours after the patient becomes asymptomatic or evidence of bacterial eradication has been obtained 1