Level 2: Mid-level evidence
A recent trial involved 121 adults hospitalized for community-acquired pneumonia who were improved after three days of IV amoxicillin (BMJ. 2006;332:1355; full-text available online without charge at: http://bmj.bmjjournals.com, accessed February 7, 2007).
Following completion of the IV amoxicillin, patients were randomized to oral amoxicillin 750 mg three times daily for five days or to placebo. Comparing three days vs. eight days of amoxicillin by intention-to-treat analysis, the clinical success rates were similar for both regimens at 10 days (88% vs. 87.5%) and at 28 days (82% vs. 77%). Adverse events occurred in 11% vs. 21% of patients (P =.1). The 95% confidence intervals (CIs) included 11%-12% differences in rates of clinical success at 10 days, so longer trials will be necessary to confirm these findings. Comparative studies with other antibiotics are also needed. Amoxicillin is not usually studied or recommended for treating pneumonia in adults. However, amoxicillin for three days has been shown to be adequate therapy in children with nonsevere pneumonia.