The Case
(ILLUSTRATION BY ALEX BAKER)
|
A 2-year-old boy comes to your office with a three-day history of fevers, cough, fatigue, and decreased appetite. He has vomited
twice today. You had seen him one week prior for an upper-respiratory infection that you felt may be viral. Physical examination
reveals a temperature of 38.8 °C (101.8 °F) and a respiratory rate of 42 bpm, as well as decreased breath sounds over the
left mid-lung field posteriorly. You diagnose him clinically with community-acquired pneumonia. What empiric treatment should
you begin? Community-acquired pneumonia (CAP) causes a spectrum of illness in children, and remains a frequent cause for outpatient visits.
While viruses can be identified in up to half of patients with CAP,1,2 distinguishing between viral and bacterial pneumonia can be exceedingly difficult.3 Therefore empiric antimicrobial therapy is often instituted. But which antibiotics will work best given your patient's
age and degree of illness? How long should your patient take to improve symptomatically? And when should you consider hospitalization?
Antimicrobial therapiesIt is important to minimize the use of broad-spectrum antibiotics for CAP and the unintended sequelae of their overuse, such
as increasing microbial resistance. That said, the following text outlines the most well-reasoned antimicrobial therapies
for outpatient CAP.
Table 1 Treatment recommendations for outpatient and inpatient CAP*
|
AMOXICILLIN, TMP-SMX. Amoxicillin remains the drug of choice for outpatient CAP (Table 1).4 There are little data to suggest whether outcomes differ in patients treated empirically with standard-dose versus high-dose
amoxicillin (or ampicillin). High-dose amoxicillin is typically chosen to account for the possibility of resistant Streptococcus pneumoniae, whose resistance can be overcome at higher drug concentrations.
In a randomized trial in a developing country, treatment with amoxicillin resulted in fewer failures than with trimethoprim-sulfamethoxazole
(TMP-SMX). Amoxicillin was also shown to be more effective in patients less than 1 year of age, and among those with severe
pneumonia (defined by cough or difficulty breathing with lower chest retractions).5 Notably, in the subset of patients with pneumococcal bacteremia, none failed amoxicillin treatment, whereas almost 30% failed
treatment with TMP-SMX. A subsequent randomized trial comparing amoxicillin to TMP-SMX, however, did not show any statistical
difference in treatment failures for non-severe CAP.6
While there had been an increase in reports of in vitro beta-lactam (ie, amoxicillin or ampicillin) resistance among S pneumoniae isolates, there has not been a significant increase in clinical failures for patients treated with these antibiotics. These
findings reinforce the use of amoxicillin (or ampicillin) as a first-line treatment for pediatric CAP.7-9 Additionally, the rate of antibiotic-resistant pneumococci has decreased with the introduction of the heptavalent pneumococcal
conjugate vaccine (PCV7).10
Practice Tools
