EFFECT OF A DUAL-LUMEN PERIPHERAL CATHETER ON THE DELIVERY OF KNOWN INCOMPATIBLE MEDICATIONS

OBJECTIVE: TO determine the degree to which a dual-lumen peripheral ca theter prevented precipitation of solutions known to be incompatible d ue to pH during simultaneous infusion in an in vitro model. METHODS: A n in vitro model was devised to simulate peripheral venous blood now f rom an antecubital source to systemic circulation. Ondansetron was sim ultaneously infused with fluorouracil, aminophylline, sodium bicarbona te, and ampicillin sodium in concentrations reflective of clinical con ditions into the Twin Cath 20/22 (the dual-lumen catheter used in this experiment). Study solutions were primed with the prepared drug solut ion and administered for 15 minutes. Phase I used Normosol-R as the di luent to gather preliminary data; phase II used human plasma, All samp les were obtained immediately before the start of the infusion and at 5, 10, and 15 minutes during the infusion, and 5 minutes after the inf usion. Samples were visually inspected at each time point for precipit ation and analyzed in duplicate by the appropriate stability-indicatin g HPLC method (except for sodium bicarbonate), Compatibility was defin ed as no visual evidence of precipitation and no more than 15% mean ch ange in final versus initial concentration. RESULTS: Phase I experimen ts showed immediate precipitation in Normosol-R within the venous flow , However, in phase II, because of the buffering capacity that plasma proteins add to plasma, no precipitation occurred. All the drug combin ations used in this study have been reported to be incompatible at the concentrations tested; however, we detected no incompatibilities. CON CLUSIONS: The results of this study indicate that using a dual-lumen p eripheral catheter, such as the Twin Cath, may allow solutions incompa tible due to pH to be administered simultaneously.