Flaws in design and conduct of clinical trials in acute otitis media

Amoxicillin/clavulanate for infections in infants and children: past, present and future

Chemical synthesis of the penicillin nucleus in the 1950s made introduction of a broad array of new and important antimicrobials, including ampicillin and amoxicillin, possible. Ampicillin was introduced in 1962 in oral and parenteral forms as the first of the semisynthetic penicillins to provide increased activity against Gram-negative bacteria. Amoxicillin replaced oral ampicillin beginning in 1974 because amoxicillin resulted in higher and more prolonged serum concentrations than did equivalent doses of ampicillin. Amoxicillin/clavulanate (Augmentin) was introduced in the United States in 1984 to enhance the activity of amoxicillin by addition of the beta-lactamase inhibitor, clavulanic acid. During the past 20 years, amoxicillin/clavulanate has proven effective for a variety of pediatric infectious diseases, particularly acute otitis media (AOM). In 2001, a new pediatric formulation, high dose amoxicillin/clavulanate (Augmentin ES-600) was approved for use in the United States. The high dose preparation addressed the needs of pediatricians by providing greater amounts of amoxicillin while maintaining the same daily dose of clavulanic acid as the regular strength formulation. Doubling the dose of amoxicillin for management of recurrent and persistent AOM was recommended in 1999 by the Centers for Disease Control and Prevention because of concern about the increased incidence of nonsusceptible strains of Streptococcus pneumoniae. The original formulation combined amoxicillin/clavulanate in a 4:1 ratio and was followed by a 7:1 ratio formulation. The high dose formulation (600 mg of amoxicillin per 5 ml) provides a 14:1 ratio of amoxicillin to clavulanate. Although management of AOM will likely undergo changes in the coming years, amoxicillin is expected to remain first line therapy for AOM. For children who fail initial therapy with amoxicillin, high dose amoxicillin/clavulanate, an oral cephalosporin or parenteral ceftriaxone is recommended.

The laws of acute otitis media

One key to successfully navigating the quagmire of otitis media is to understand otitis media and share that understanding with parents. The Laws of Otitis Media can be useful in this endeavor. Another key to success is to help parents understand that they and their child's physician are partners in the goal of preventing AOM as much as possible, and treating episodes as precisely as possible when they occur. Parents need to know that AOM usually occurs at < 3 years of age and most normal children experience some AOM. The number of AOM episodes depends on a combination of inherited factors that are compounded by immature immunity and anatomy plus the degree of exposure to provoking respiratory pathogens. A firm understanding of the difference between AOM and OME makes it simpler to withhold antibiotics for OME; and understanding that infrequent AOM usually gets well without antibiotics also may reduce some of parents' anxieties. Parents of patients with frequent AOM deserve more guidance about the need for more potent antibiotics and the reduced expectations for cure despite use of appropriate antibiotics. Clinicians need to share with parents the fact that most information about antibiotics and AOM comes from studies sponsored by pharmaceutical companies, with the goal of optimizing the chance that the company's drug would appear to be a good choice. Therefore, only by understanding critical study-design characteristics that ensure fair and proper comparison, will the clinician (or parent using the Internet) be able to decide which drugs are best. Because there are so few well-designed studies, pharmacodynamics has become an alternative method to decide which drugs are best. Practitioners may need to rely on an expert to help interpret the application of pharmacodynamics to local AOM pathogens. While shorter courses of antibiotics are attractive from the compliance and perhaps even the reduction of resistance perspective, failure rates will be higher in young children with tough-to-treat AOM. Further, some of the better tasting or more convenient drugs turn out to be less effective in these same hard-to-treat patients. To further minimize parental anxiety, clinicians should share the fact that it is very rare to see severe complications or lifelong hearing problems due to AOM that is reasonably managed. This is important because the available tools to prevent AOM are limited in number and efficacy. The Laws of AOM can be a basis for busy practitioners to establish a structure for constructively sharing information and responsibility with parents concerning AOM.