Evaluation of oral, intravenous, and intramuscular aureomycin and the correlation between the in vivo and in vitro activity.

Oral administration of aureomycin is currently the method of choice. The intravenous route is occasionally used when oral administration becomes difficult by reason of excessive nausea, vomiting, or diarrhea. The intramuscular injection of aureomycin is now but little used since early reports by some workers indicated that blood levels obtained by this route were relatively low, and, more important, considerable pain was observed following intramuscular administration (Brainerd et al., 1949; Bryer et al., 1949). In our preliminary experimental studies the intramuscular administration of aureomycin appeared to be unusually effective, and in the present work we will report on (1) the relative effectiveness of aureomycin in experimental pneumococcus infections in mice when given orally, intravenously, and intramuscularly, and (2) the correlation between the concentration of aureomycin inhibiting the pneumococcus in vitro and in vivo.