Should You Give Amoxicillin?
Yes, amoxicillin should be prescribed as first-line therapy for most bacterial infections where antibiotic treatment is indicated, including acute bacterial rhinosinusitis, acute otitis media, pharyngitis, and community-acquired pneumonia, due to its proven efficacy, safety profile, narrow spectrum, and cost-effectiveness. 1
When to Prescribe Amoxicillin
Respiratory Tract Infections
For acute bacterial rhinosinusitis (ABRS) in adults, amoxicillin is the recommended first-line antibiotic when the decision is made to treat. 1 The standard adult dose is 500 mg three times daily or 875 mg twice daily for 5-7 days. 1 However, observation without antibiotics is a valid option for selected adults with uncomplicated ABRS who have mild illness (mild pain and temperature <38.3°C) and assurance of follow-up. 1
For acute otitis media, amoxicillin is the first-choice antibiotic. 1 The recommended pediatric dose is 80-90 mg/kg/day to provide adequate coverage against penicillin-resistant Streptococcus pneumoniae. 1 Observation without antibiotics for 48-72 hours is an option for children 6 months to 2 years with non-severe illness and uncertain diagnosis, or children ≥2 years without severe symptoms. 1
For group A streptococcal pharyngitis, penicillin remains the treatment of choice, though amoxicillin is often used in younger children due to taste considerations and availability as suspension. 1 Treatment hastens symptomatic improvement by 1-2 days and reduces the risk of rheumatic fever (RR 0.27; 95% CI 0.12-0.60). 1
Dental Infections
Do not use antibiotics for acute apical periodontitis and acute apical abscesses, as surgical drainage is the key treatment. 1 Antibiotics may be helpful only in cases of systemic complications (fever, lymphadenopathy, cellulitis), diffuse swelling, or in medically compromised patients. 1
Lower Respiratory Tract Infections
For community-acquired pneumonia in children, amoxicillin 50 mg/kg/day in 2 divided doses for 5 days is recommended as first-line treatment. 2 A 5-day course is as effective as a 10-day course for uncomplicated CAP in children under 10 years old. 3
When to Use Amoxicillin-Clavulanate Instead
Switch to amoxicillin-clavulanate (high-dose: 2000 mg/125 mg twice daily in adults or 90 mg/kg/6.4 mg/kg/day in children) when risk factors for resistant bacteria are present: 1, 4, 2
- Recent antibiotic use within the previous 30 days 4, 2
- Daycare attendance in children 2
- Failed previous antibiotic therapy 4
- High prevalence of penicillin-resistant S. pneumoniae (>10%) in the community 4, 2
- Moderate to severe infections 4
- Age >65 years or significant comorbidities 4
- Concurrent conjunctivitis (otitis-conjunctivitis syndrome) 2
For acute otitis media, use high-dose amoxicillin-clavulanate if the child received amoxicillin in the previous 30 days or has otitis-conjunctivitis. 2
When NOT to Prescribe Amoxicillin
Do not prescribe antibiotics for acute sore throat with 0-2 Centor criteria, as the modest benefit (1-2 days symptom reduction) does not outweigh the harms of side effects, antimicrobial resistance, and medicalization. 1
Do not use antibiotics for chronic periodontitis or peri-implantitis. 1
Avoid amoxicillin monotherapy for lower urinary tract infections due to high resistance rates (median 75% of E. coli isolates resistant). 1 Use amoxicillin-clavulanate, nitrofurantoin, or sulfamethoxazole-trimethoprim instead. 1
Reassessment and Treatment Failure
If the patient worsens or fails to improve within 48-72 hours, reassess to confirm the diagnosis, exclude other causes, and detect complications. 1 If ABRS is confirmed in a patient initially managed with observation, begin antibiotic therapy. 1 If initially treated with amoxicillin, switch to amoxicillin-clavulanate or an alternative agent. 1
Critical Dosing Considerations
For children with severe infections or risk factors, use high-dose amoxicillin (80-90 mg/kg/day) to achieve adequate serum concentrations against resistant S. pneumoniae. 1, 4 The maximum pediatric dose is 4000 mg/day. 2
In areas with high penicillin-resistant S. pneumoniae prevalence (>10%), always use high-dose formulations: 2000 mg/125 mg twice daily for adults or 90 mg/kg/day for children. 4, 2
Common Pitfalls to Avoid
Do not use amoxicillin in older children or adolescents with suspected Epstein-Barr virus infection (mononucleosis) due to the risk of severe rash. 1
Do not prescribe antibiotics immediately for mild acute sore throat; delayed prescribing (>48 hours after initial consultation) is a valid option with no significant difference in complication rates. 1
Avoid underdosing in the era of increasing antimicrobial resistance—use 80-90 mg/kg/day in children and high-dose formulations when indicated. 4, 2