Visual compatibility of oritavancin diphosphate with selected coadministered drugs during simulated Y-site administration

Purpose. The visual compatibility of the new intravenous antibiotic oritavancin diphosphate with various drugs commonly administered to patients in acute care settings was studied. Methods. Clinically used concentrations of 37 drugs, including antibiotics, sedatives, analgesics, and cardiovascular agents, were evaluated in 1:1 mixtures with oritavancin concentrations of 0.8, 1.2, and 2 mg/mL. Oritavancin solutions were prepared in 5% dextrose injection and mixed with each test drug solution. The mixtures were then visually observed over a period of four hours at room temperature. The pH of the mixtures was also determined immediately and four hours after mixing. Compatibility was defined as the absence of any color change, haze, fibers, particles, and precipitate. Results. Of the 37 tested drugs, 23 were visually compatible with all three concentrations of oritavancin over the four-hour study period. Drugs formulated at a basic or neutral pH were more likely to be incompatible with oritavancin. Conclusion. Oritavancin diphosphate was visually incompatible with many intravenous drugs that are likely to be coadministered in acute care settings.