Current guidelines that recommend a seven-to 10-day treatment course for adults with uncomplicated pneumonia are not based on scientific evidence. Because studies have shown good results with three-day treatment courses in children, el Moussaoui and colleagues compared three- and eight-day antibiotic courses in adults with mild to moderate uncomplicated community-acquired pneumonia (CAP).

The randomized, double-blind, placebo-controlled trial included patients 18 years or older admitted to nine Dutch hospitals because of clinical symptoms and signs of CAP with a severity index of 110 or less. Patients were required to have chest radiograph findings compatible with pneumonia and no evidence of complications. All patients initially received intravenous amoxicillin for 72 hours. The respiratory symptoms of dyspnea, cough, sputum production, and sputum color, and overall clinical improvement were each ranked using a five-point scale. Patients who improved by two or more points, had a temperature lower than 100.4° F (38° C), and could take oral medications were randomly assigned to 750-mg oral amoxicillin or placebo taken three times daily for five days. Patients were reevaluated at days 7, 10, 14, and 28 using a standardized CAP scoring system, physical examination, laboratory studies, and sputum cultures. Chest radiography was obtained at baseline and days 10 and 28. Antibodies for viral and atypical organisms that cause CAP were assessed at baseline and day 28. Patients were asked about adverse events for up to 10 days.

The three-day treatment group (56 patients) had more patients who smoked and who had more severe symptoms at baseline compared with the eight-day treatment group (63 patients). Four treatment failures occurred in each group. Based on intention to treat, 89 percent of patients in each group were cured. Ninety-three percent of patients who adhered to protocol were cured in each group. At day 28, the median CAP score was 82 in the three-day treatment group and 74 in the eight-day group. The median length of hospitalization was one day longer and the occurrence of adverse effects was higher (21 versus 11 percent) in the eight-day group.

The authors conclude that three-day antibiotic therapy provides outcomes comparable to eight-day therapy in patients with mild to moderate-severe CAP who show substantial improvement after three days of therapy. Although the study has several factors that limit its generalizability, it shows T the potential for substantial savings in antibiotic treatment of CAP in the primary care setting. These reductions in antibiotic use could impact the development of bacterial resistance to antibiotics and contribute to savings in health care costs.