What is the recommended dosage of amoxicillin (amoxicillin) for the treatment of acute otitis media (AOM)?

Amoxicillin Dosing for Acute Otitis Media

High-dose amoxicillin (80-90 mg/kg per day in 2 divided doses) is the recommended first-line treatment for acute otitis media due to its effectiveness against common bacterial pathogens, safety profile, low cost, acceptable taste, and narrow microbiologic spectrum. 1, 2

First-Line Treatment Options

• High-dose amoxicillin achieves middle ear fluid levels that exceed the minimum inhibitory concentration of intermediately resistant Streptococcus pneumoniae and many highly resistant serotypes for a longer period of the dosing interval 1, 2
• The high-dose regimen (80-90 mg/kg/day) has demonstrated superior bacteriologic and clinical efficacy compared to standard dosing, particularly against resistant S. pneumoniae strains 3
• For adults with acute otitis media, high-dose amoxicillin is also recommended as the initial treatment 4

Special Considerations for Alternative First-Line Therapy

For certain patient populations, high-dose amoxicillin-clavulanate should be used as initial therapy:

• Patients who have taken amoxicillin in the previous 30 days 1, 2
• Patients with concurrent conjunctivitis (otitis-conjunctivitis syndrome) 1
• Patients requiring coverage for beta-lactamase-producing organisms like Haemophilus influenzae and Moraxella catarrhalis 1, 2

The recommended dosage for amoxicillin-clavulanate is:

• 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate (amoxicillin to clavulanate ratio of 14:1) in 2 divided doses 1, 2

Alternative Options for Penicillin-Allergic Patients

For patients with non-type I hypersensitivity to penicillin, alternative options include:

• Cefdinir (14 mg/kg/day in 1 or 2 doses) 1, 2
• Cefuroxime (30 mg/kg/day in 2 divided doses) 1, 4
• Cefpodoxime (10 mg/kg/day in 2 divided doses) 1, 2
• Ceftriaxone (50 mg IM or IV per day for 1 or 3 days) for severe cases 1

Management of Treatment Failure

If a patient fails to respond to initial treatment within 48-72 hours:

• Reassess to confirm the diagnosis of acute otitis media 4
• For patients who initially received amoxicillin, switch to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses) 1, 2
• Alternatively, ceftriaxone (50 mg IM or IV for 3 days) may be used for treatment failures 2, 4
• For persistent failure after second-line therapy, consider consultation with an otolaryngologist for tympanocentesis/drainage 1

Clinical Pearls and Pitfalls

• Resistance to antimicrobials is increasingly influencing the selection of empiric antibiotic therapy for otitis media and is a main reason for treatment failure 5
• Beta-lactamase-producing organisms, particularly H. influenzae, are the predominant pathogens isolated from children failing high-dose amoxicillin therapy 3
• The incidence of diarrhea is significantly lower with twice-daily dosing compared to three-times-daily dosing regimens 6
• While on antibacterial treatment, patients may worsen slightly initially but should stabilize within the first 24 hours and begin improving during the second 24-hour period 4

Monitoring and Follow-Up

• Patients should be reassessed if symptoms persist or worsen after 48-72 hours of initial therapy 1, 4
• Pain management should be addressed regardless of whether antibacterial agents are used, especially during the first 24 hours 4
• During treatment with antibacterial agents, monitor for common adverse effects including diarrhea (most common), nausea, skin rashes, and urticaria 6

By following these evidence-based recommendations for amoxicillin dosing in acute otitis media, clinicians can optimize treatment outcomes while minimizing the risk of antimicrobial resistance.