文本框: THE CHALLENGES IN ANTIMICROBIAL THERAPY OF PEDIATRIC PNEUMONIA Bradley JS Children’s Hospital and the University of California at San Diego, California, USA Lower respiratory tract infections (LRTI) are among the most common infectious diseases of children, caused by a diverse number of viruses, bacteria, mycoplasma, mycobacteria and fungi. Although anti-infective therapy has resulted in improved outcomes of children with documented infections, use of antibiotics for a presumed viral infection has promoted antibiotic resistance in the most common bacterial LRT pathogens. By approaching diagnosis with a combination of: knowledge of the seasonal prevalence and local activity of certain viral pathogens; the age-specific attack rates of certain pathogens; the clinical presentation; the clinical examination; and on occasion, laboratory testing and chest x-rays, the etiology of the LRT pathogen may be defined with reasonable accuracy. Antibiotic therapy should be based on the age of the child, the severity of the infection and the knowledge of the resistance patterns of prevalent pathogens, particularly Streptococcus pneumoniae and Haemophilus influenzae. For serious LRTI caused by the vast majority of penicillin-resistant Streptococcus pneumoniae, ceftriaxone, cefotaxime and cefuroxime represent reasonable parenteral therapy without the need for the addition of vancomycin. Ceftriaxone provides the option of once daily intramuscular administration for moderate to severe disease, for convalescent outpatient therapy, and for those who cannot tolerate oral therapy. For treatment of less severe disease or for convalescent oral therapy, high dose amoxicillin (80-100 mg/kg/day) is preferred; cefuroxime, cefpodoxime, cefprozil and cefdinir are alternatives, as are erythromycin, azithromycin and clarithromycin for susceptible organisms.