SAN DIEGO (FRONTLINE MEDICAL NEWS) – Macrolide use showed lower treatment failure rates than did amoxicillin or beta-lactam treatment for pediatric community acquired pneumonia (CAP) patients, according to a study presented at an annual scientific meeting on infectious diseases.

While guidelines recommend amoxicillin as the first-line therapy against CAP, investigators have noticed an increase in macrolide prescriptions to pediatric outpatients, despite reported shortcomings in its use against atypical pneumonia.

“Macrolides are probably prescribed out of proportion to the presence of atypical pneumonia in that practice setting,” said Lori Handy, MD, of Children’s Hospital of Philadelphia. This could be an issue, according to Dr. Handy: “We also know that depending on the study, up to 40% of Streptococcus pneumoniae is resistant to macrolides, meaning there are children out there who may have S. pneumoniae who are receiving therapy not targeted at their disease pathogen.”

To examine the possible impact of an increase in macrolide prescriptions, the investigators conducted a retrospective cohort study of 10,470 CAP pediatric patients across 31 primary care practices in the Children’s Hospital of Philadelphia network who were diagnosed between January 2009 and December 2013.

The studied cohort was split into three groups based on treatment options: amoxicillin monotherapy (4,252, 40.6%), macrolide monotherapy (4,459, 42.6%), and broad-spectrum beta-lactams (1,759, 16.8%).

Patient age ranged from 3 months to 18 years, the majority were white, with a roughly equal number of each sex. Of the children studied, 634 (6.1%) experienced treatment failure, defined as a change in antibiotics, an emergency department visit for related symptoms, or hospitalization for pneumonia, all of which had to occur more than 24 hours after a pediatric visit, according to Dr. Handy.

Of the children who failed treatment, 341 (54%) were in the amoxicillin group, 145 (23%) were in the macrolide group, and 147 (23%) were in the broad-spectrum group.

Patients younger than 5 years old who received macrolide therapy were half as likely to experience treatment failure compared with those given amoxicillin (odds ratio [OR] .52 [95% confidence interval (CI), 0.34-0.78]).

“What this translates to in practice is that about 32 children would need to treated with macrolides to prevent one failure in the amoxicillin group,” said Dr. Handy.

Patients 5 years and older showed even lower odds of treatment failure, at approximately one-third the rate of amoxicillin treated patients (OR .31 [95% CI, 0.23-0.92]).

Dr. Handy stated that the retrospective nature of the study and the possibility of changes in the epidemiology of CAP occurring since 2013 should be considered when evaluating the findings.

In addition, she pointed out, CAP is a clinical diagnosis, and there is generally no microbiological data associated with it in order to determine the etiology of the infection.

Overall, in healthy children with CAP, it would be better to use macrolide antibiotics compared with amoxicillin, Dr. Handy concluded. However, without the microbiological data, a more randomized, controlled trial would be needed to determine how to best treat these patients, she added.

During discussion, members of the audience asked about the appropriateness of measuring a change in antibiotics as an endpoint, especially in children with viral pneumonia, who may have had parents request stronger medication when their children did not improve quickly enough.

The 47 patients who were hospitalized would not have provided enough control to properly test the results, Dr. Handy replied, although she did acknowledge the potential issue of viral infections.

She stated the need for further study to assess its possible impact, saying she didn’t know whether viral infections may have skewed their results. “Either they’ve done nothing because they’re equally distributed among the groups or they’ve pushed them one way or the other way,” she said.

Dr. Handy and her colleagues reported having no relevant financial disclosures. The event was the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.

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