What is the dosage and treatment duration for syrup amoxicillin (amoxicillin) in bacterial infections?

Amoxicillin Dosage and Treatment Duration for Bacterial Infections

For bacterial infections, amoxicillin syrup should be dosed at 45 mg/kg/day in 2 divided doses for standard treatment, or 80-90 mg/kg/day in 2 divided doses for severe infections or in areas with high antimicrobial resistance, with treatment typically lasting 10 days for most bacterial infections. 1, 2

Dosing Guidelines by Age and Weight

Children (Weight < 40 kg)

• Standard dose: 45 mg/kg/day divided every 12 hours or 20-25 mg/kg/day divided every 8 hours for mild to moderate infections 2, 1
• High dose: 80-90 mg/kg/day divided every 12 hours or 40-45 mg/kg/day divided every 8 hours for severe infections or in areas with high prevalence of resistant organisms 2, 1
• For children under 3 months: Maximum recommended dose is 30 mg/kg/day divided every 12 hours due to incompletely developed renal function 1

Adults and Children (Weight ≥ 40 kg)

• Standard dose: 500 mg every 12 hours or 250 mg every 8 hours for mild to moderate infections 1
• High dose: 875 mg every 12 hours or 500 mg every 8 hours for severe infections 1

Treatment Duration by Infection Type

Respiratory Tract Infections

• Streptococcal pharyngitis: 10 days to prevent acute rheumatic fever 2
• Community-acquired pneumonia:
  • 10 days for pneumococcal pneumonia 2
  • At least 14 days for atypical pneumonia 2
• Acute bacterial sinusitis: 10 days is standard practice 2

Other Infections

• H. pylori infection (adults): 14 days (as part of triple or dual therapy) 1
• Dental infections: 7-10 days 3

Special Considerations

Antimicrobial Resistance

• Consider high-dose amoxicillin (80-90 mg/kg/day) in communities with high prevalence of non-susceptible S. pneumoniae (>10%) 2
• Risk factors for resistant organisms include:
  • Age younger than 2 years 2
  • Attendance at childcare 2
  • Receipt of antimicrobial treatment within previous 30 days 2
  • Areas with high prevalence of β-lactamase-producing H. influenzae 2

Renal Impairment Adjustments

• For patients with GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours 1
• For patients with GFR <10 mL/min: 500 mg or 250 mg every 24 hours 1
• Patients on hemodialysis: Administer an additional dose both during and at the end of dialysis 1

Administration Tips

• Administer at the start of a meal to minimize gastrointestinal intolerance 1
• For oral suspension: Shake well before using and refrigerate (preferred but not required) 1
• Discard any unused portion of reconstituted suspension after 14 days 1

Common Pitfalls and Caveats

• Inadequate dosing: The traditional amoxicillin dosing of 40 mg/kg/day may be inadequate for resistant S. pneumoniae, particularly during viral coinfection; higher doses of 75-90 mg/kg/day may be needed 4
• Treatment duration: While shorter courses (3 days) have been studied for some conditions like community-acquired pneumonia, the standard 10-day course remains recommended for streptococcal infections to prevent complications 2, 5
• Penicillin allergies: For patients with penicillin allergy, alternative antibiotics should be considered based on the specific infection 2
• Surgical intervention: For dental infections, antibiotics alone without surgical intervention are insufficient; drainage or other dental procedures should not be delayed 3

Remember that amoxicillin remains the antimicrobial agent of choice for first-line treatment of many bacterial infections due to its effectiveness, safety, acceptable taste, low cost, and relatively narrow microbiologic spectrum 2.