Oral amoxicillin is globally the most commonly recommended first-line treatment because it is still effective against the majority of bacterial pathogens that cause CAP, is well tolerated, and inexpensive [
4,
5]. In case of penicillin allergy or infections with
M. pneumoniae or
Chlamydia pneumoniae, macrolides and tetracyclines can be used at any age or > 7 years of age, respectively, according to the IDSA [
4] (Table
2).
Table 2
Antibiotic treatment for children with non-severe CAP
First line | Amoxicillin PO | (25–)c 40–45 mg/kg/dose twice a day (maximum 3000 mg/day) | (3–)c 5 days |
Penicillin allergyd or Mycoplasma pneumoniae and Chlamydia pneumoniae | Clarithromycin POe | 7.5 mg/kg/dose twice a day (maximum 1000 mg/day) | 5 days |
Doxycycline POf (> 7 years) | First day: 2 mg/kg/dose twice a day (maximum 200 mg/day) Days 2 to 5: 2 mg/kg/dose once a day (maximum 100 mg/day) | 5 days |
Several studies have recently investigated different durations and doses of amoxicillin for children with CAP in the outpatient setting. Most national guidelines in both low- and high-income countries recommend durations for 5–10 days, but these recommendations are based on sparse evidence [
14]. Because current diagnostic methods cannot reliably distinguish between bacterial and viral CAP, no microbiological testing was performed in most studies for patient enrolment. Consequently, the effect of antibiotics on viral CAP was also evaluated and, therefore, likely underestimated in relation to bacterial CAP, which was the intended target of these studies (i.e., “Pollyanna phenomenon”) [
13]. For example, the SAFER study (Canada, 2 centres, 281 children) confirmed that 5 days of amoxicillin was comparable to 10 days in children with radiologically confirmed CAP [
15]. However, viruses (predominantly RSV) were detected in about two-thirds of patients in that study who were additionally tested by PCR from nasopharyngeal swabs [
15]. The CAP-IT study (UK, 29 centres, 824 children) showed that even 3 days of amoxicillin was non-inferior to 7 days with regard to the need for antibiotic re-treatment [
16]. Furthermore, lower doses of amoxicillin (30–50 mg/kg/day) were non-inferior to higher doses (70–90 mg/kg/day) for both treatment durations. However, CAP was exclusively clinically diagnosed in that study (no chest radiography and no microbiological testing). Very young children were predominantly included (median age 2.5 years), so it is likely that the majority of children in this study had viral CAP, which makes it difficult to judge the study result of similar treatment failure with varying doses and duration of amoxicillin [
16]. Nevertheless, the clinical diagnosis of CAP in this study reflects real-word practice and is in line with current guidelines; thus, the results may be translated to children with non-severe CAP in the outpatient setting. This is also supported by recent systematic reviews and meta-analyses showing that a short duration of 3–5 days seems equally effective and safe compared with the longer duration of 7–10 days [
14,
17].
Current recommendations based on these studies include a treatment duration of 5 days for non-severe CAP in children. If the child has already recovered previously, 3 days may also be appropriate.