Trimethoprim-Sulfamethoxazole Compared with Ampicillin in Acute Infectious Exacerbations of Chronic Bronchitis: A Double-Blind, Crossover Study

Abstract

Combinations of trimethoprim (TMP) and sulfamethoxazole (SMZ) have been used to treat patients with chest infections caused predominantly by Haemophilus influenzae and Diplococcus pneumoniae. In a single blind comparative trial with ampicillin TMP-SMZ was superior in reducing volume of sputum and purulence and in eradicating pathogens from the sputum. Two groups of patients with severe bronchitis received the combination for periods of between three and 30 months, with excellent clinical effect and minimal effects on the blood count. No resistant strains of H. influenzae or D. pneumoniae emerged. Pneumonia, lung abscess, and bronchiectasis were also treated, with excellent clinical response. The pathogenic organisms eradicated from the sputum in these cases included penicillin-resistant staphylococci and Klebsiella. It has been demonstrated that TMP is concentrated in the sputum. This may account for the efficacy of TMP-SMZ in treating chest infections.