In vitro activity of an orally administered streptogramin (RPR 106,972) compared to quinupristin/dalfopristin and erythromycin

The antibacterial activities of RPR 106,972 and quinupristin/dalfopristin (RP 59,500) were determined by the broth microdilution susceptibility test method. No major differences were seen among MICs for 863 isolates representing 22 species, However, there were minor twofold differences in MICs for some species. On a weight-to-weight basis, the activities of the oral and parenteral streptogramins were essentially the same. Because the route of administration and the pharmacokinetics differ, it is not necessarily appropriate to extrapolate such in vitro observations to predict identical clinical and bacteriological response rates for the two drugs.