Incompatibilities of lornoxicam with 4 antiemetic medications in polyolefin bags during simulated intravenous administration

The administration of drugs by patient-controlled analgesia (PCA) is routinely practiced for the management of postoperative pain. It is common for 2 or more drugs to be combined in PCA solutions. The combination of analgesics and antiemetic agents is frequently required. Unfortunately, the compatibility and stability of lornoxicam and antiemetic agents, such as droperidol, ondansetrone, granisetron, and tropisetron, has not been determined. The aim of this study was to evaluate the compatibility and stability of solutions containing lornoxicam with the 4 antiemetic agents in combination for PCA administration. In our study, test samples were prepared in triplicate by adding 40 mg lornoxicam and 5 mg droperidol, 8 mg ondansetron, 6 mg granisetron, or 5 mg tropisetron to 100-mL polyolefin bags of sodium chloride 0.9% and stored at 25 °C. The analgesic mixture samples were visually inspected for precipitation, cloudiness, and discoloration at each sampling interval. Drug concentrations were determined using high-performance liquid chromatographic (HPLC) analysis. No loss of lornoxicam occurred with any of the 4 antiemetic agents tested for up to 48 hours. However, the contents of droperidol, ondansetron, granisetron, and tropisetron were significant loss >48 hours. After storage of 4.0 to 48.0 hours, the presence of a slight precipitate was observed in all the injection combinations. The results indicate that combinations of lornoxicam with droperidol, ondansetrone, granisetron, or tropisetron in infusion solution during simulated intravenous PCA administration were incompatibility when stored protected from light at 25 °C.