Acute Otitis Media: How Long Should You Treat?

Antimicrobial stewardship has become a very important practice in optimal patient care. We want to try to limit as much unnecessary antibiotic exposure as possible, while providing optimal treatment. Treating acute otitis media (AOM) may seem simple enough. High dose amoxicillin 80-90 mg/ kg per day in 2 divided doses is the recommended medication for treatment of an initial episode of AOM.¹

With antimicrobial stewardship practices, not only do we want to narrow antimicrobial therapy to specific organisms, but also provide appropriate duration of treatment. The duration for treating AOM in children is unclear. The idea of shorter therapy leading to less antimicrobial resistance is very true, but in AOM it may be leading to treatment failure causing additional exposure to antibiotics. Children younger than 2 years with AOM may take longer to improve clinically than older children.¹ The usual 10-day course of therapy was derived from the duration of treatment of streptococcal pharyngotonsillitis.¹

Several studies have shown that 10-day course of antibiotics are favored in children younger than 2 years old. This is consistent with the findings of a recent study by Hoberman A, Paradise JL, Rockette H et al. published in the New England Journal of Medicine.

The study involved children between the ages of 6 to 23 months that were diagnosed with AOM based on specified criteria. Statistically significant clinical failure was shown to occur more frequently in the 5-day treatment group compared to the 10-day treatment group in children who had both ears affected by AOM and exposure to other children for 10 or more hours per week.² There was a higher percentage of children in the 10-day treatment group that had greater than a 50% decrease in symptoms compared to children in the 5-day treatment group (91% vs. 80%, P=0.003).² The antibiotic of choice in this study was amoxicillin-clavulanate, which can be used as an alternative in patients that have received amoxicillin in the past 30 days or have otitis-conjunctivitis syndrome.¹

Clinical improvement should be noticed within 48 to 72 hours of initiating antibiotics for AOM. Symptoms may worsen during the 24 hours after diagnosis of AOM.¹ Decrease in initial symptoms such as fever, irritability, trouble sleeping etc. should start to occur within the following 48 hours. If no clinical improvement occurs with antibiotics within the 48 to 72 hour time period, another etiology such as a viral pathogen may be causing the infection.

The use of amoxicillin-clavulanate may have been favored in this study due to the additional coverage it provides for certain strains of bacteria. The 3 most common bacterial organisms that cause AOM are Streptococcal pneumoniae, Non-typeable Haemophilus influenzae, and Moraxella catarrhalis.¹

Organisms such as H. influenzae and M.catarrhalis could potentially produce a beta-lactamase enzyme that does not allow high dose amoxicillin to be efficacious. Addition of clavulanate, a beta lactam inhibitor, allows for appropriate drug concentrations to be achieved providing optimal coverage of those organisms. For coverage of S. pneumoniae, high-dose amoxicillin will yield middle ear fluid levels that exceed the minimum inhibitory concentration of all S. pneumoniae strains that are intermediately resistant to penicillin with appropriate dosing intervals.¹ The study also observed no significant difference between the 10-day treatment group and 5-day treatment group in rates of adverse events, AOM recurrence, or antimicrobial resistance.²

Many studies in the past have shown 10-day treatment of AOM to be the most efficacious in children that are less than 2 years old. As children increase in age, duration of treatment is recommended to be reduced to 7 days or even 5 days in children 6 years or older.¹ Most likely due to the fact that the immune system becomes stronger as children grow. Limiting unnecessary antibiotic exposure is very important, especially in younger populations to avoid development of resistance. This study addressed the concern of antimicrobial resistance with 10-day treatment, finding no additional risk of resistance with longer therapy and overall fewer clinical treatment failures in children between the ages of 6-23 months.

References

Lieberthal AS, Carroll AE, Chonmaitree T et al. The diagnosis and management of acute otitis media. American Academy of Pediatrics. 2013;131:e964—e999.

Hoberman A, Paradise JL, Rockette H et al. Shortened antimicrobial treatment for Acute Otitis Media in young children. N Engl J Med. 2016;375:2446-2456