Preliminary results have recently shown that an early switch from parenteral antimicrobials to an oral substitute provides an effective means of treating pneumonia in pediatric patients. In a controlled randomized study, 62 children with community-acquired lobar/segmental pneumonia were selected to receive 8 days of cefixime or amoxicillin-clavulanate after an initial therapy of two doses of parenteral ceftriaxone. Enrollment criteria included: age 6 months to 5 years, fever > 38.5 degrees C, white blood cell (WBC) count > or = 15,000/ mm3, and lobar/segmental pneumonia on chest radiograph. Twenty-nine patients were randomized to receive oral cefixime and 33 to oral amoxicillin-clavulanate. The two groups were comparable in the following pretreatment parameters: age, duration of illness, temperature, mean WBC count, erythrocyte sedimentation rate, C-reactive protein, and need for hospitalization. Days of resolution of high fever, tachypnea, cough, grunting, and laboratory test abnormalities were similar in the two groups. Clinical response at the end of treatment showed cure, improvement, and failure in 97%, 3%, and 0%, respectively, in the cefixime group and in 88%, 6%, and 6%, respectively in the amoxicillin-clavulanate group (P = NS). We conclude that young children with community-acquired lobar/segmental pneumonia can be successfully treated with 2 days of parenteral ceftriaxone followed by 8 days of oral cefixime or amoxicillin-clavulanate.