SEVERAL fixed-combination antimicrobial preparations are available to the practitioner. As recently pointed out by McCabe,1 there is little factual information to support the superiority of antibiotic combinations over single antibiotics in most clinical situations. Dowling2 also can find no justification for the marketing of fixed-combinations of antibiotics. However, fixed-dosage antimicrobials continue to be marketed, factual information supporting the superiority of these preparations remains scarce, and, surprisingly enough, many physicians continue to use these products.
Evaluation of antibiotics in the more frequently encountered infections such as pneumonia, otitis media, and bronchitis is hampered by the poor correlation with bacteria isolated from the upper respiratory tract and the true etiology of the infection. However, β-hemolytic Streptococcus, group A, isolated from the throat of a patient with pharyngitis, can reliably be considered the etiologic agent of that disease. Since this organism is essentially the only bacterium producing infection in the pharynx