What is the recommended dosing of amoxicillin (Amoxil) for an adult with acute otitis media (AOM)?

Amoxicillin Dosing for Adult Acute Otitis Media

For adults with acute otitis media (AOM), the recommended dose of amoxicillin is 875 mg twice daily for 5-7 days. 1

First-Line Treatment Options

Standard Adult Dosing

• Amoxicillin 875 mg twice daily for 5-7 days
• This dosing provides adequate coverage against susceptible and intermediately resistant pneumococci, which are common pathogens in AOM

Alternative for Recent Antibiotic Use or Suspected Resistant Organisms

• Amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days 1
• Consider this option if:
  • Patient has taken antibiotics in the previous 30 days
  • Patient has concurrent conjunctivitis
  • Coverage for beta-lactamase-producing organisms is desired (H. influenzae, M. catarrhalis)

Rationale for Amoxicillin as First-Line Therapy

Amoxicillin is recommended as first-line therapy for AOM because:

• It is effective against common AOM bacterial pathogens 2
• It has a favorable safety profile
• It is cost-effective
• It has a narrow microbiologic spectrum, minimizing collateral damage 2

For Penicillin-Allergic Patients

If the patient has a non-type I hypersensitivity reaction to penicillin, consider:

• Cefdinir (300 mg twice daily)
• Cefuroxime (250-500 mg twice daily)
• Cefpodoxime (200 mg twice daily) 2, 1

For type I hypersensitivity reactions, consider consultation with an infectious disease specialist.

Treatment Failure Management

If symptoms worsen or fail to improve after 48-72 hours of initial therapy:

1. Reassess the diagnosis to confirm AOM and exclude other causes 2
2. If AOM is confirmed, change to an alternative antibiotic:
   • Amoxicillin-clavulanate 875/125 mg twice daily (if started on amoxicillin)
   • Respiratory fluoroquinolone (if not contraindicated)
   • Consider ceftriaxone for severe cases 2, 1

Duration of Therapy

While pediatric patients typically require 10-14 days of therapy, adults with uncomplicated AOM can be effectively treated with a shorter 5-7 day course 1. This shorter duration is supported by the Infectious Diseases Society of America guidelines for uncomplicated infections in adults.

Important Clinical Considerations

• Taking medication with food can help reduce gastrointestinal side effects
• Diarrhea occurs in approximately 7-11% of patients; if severe or bloody, immediate medical attention should be sought 1
• Dosage adjustment may be necessary in patients with severe renal dysfunction

Common Pitfalls to Avoid

1. Underdosing in larger adults: Unlike pediatric dosing (which is weight-based), adult dosing is standardized regardless of weight
2. Prolonged therapy: Extending treatment beyond 7 days in uncomplicated cases does not improve outcomes and increases risk of side effects
3. Failure to reassess: If symptoms don't improve within 48-72 hours, the diagnosis should be reconsidered or antibiotic changed
4. Inappropriate use of fluoroquinolones: These should be reserved for treatment failures or specific allergic situations, not as first-line therapy

By following these evidence-based recommendations, clinicians can effectively treat adult AOM while promoting antimicrobial stewardship.