Visual compatibility of furosemide with phenylephrine and vasopressin

Published information about drug compatibility sometimes contradicts evidence witnessed during day-to-day practice. For example, Trissel’s Tables of Physical Compatibility describes vasopressin injection (Parke-Davis) 4 units/mL and phenylephrine hydrochloride (Winthrop Pharmaceuticals) 4 mg/mL as physically compatible for up to three hours when combined with furosemide (Hoechst-Roussel) 5 mg/mL in common infusion solutions.1 However, at our institution concurrent Y-site administration of these agents in the clinical setting has resulted in the immediate formation of a white precipitate. Therefore, we studied the visual compatibility of furosemide with drugs commonly used at our institution in the intensive care setting during a simulated Y-site administration. Furosemide injection 200 mg (20 mL)a was diluted in a 50-mL bag of 5% dextrose injection (D5W)b or 0.9% sodium chloride injection (NS),c yielding a final nominal furosemide concentration of 200 mg/50 mL. Phenylephrine hydrochloride 160 mg (16 mL)d was diluted in a 250 mL bag of D5We or NSf. Vasopressin 100 units (5 mL)g was diluted in a 250-mL bag of D5We or NS.f Before drug injection into the bags, the volume of fluid to be added to each bag was removed from each bag. All of the drug preparations were advanced through a low protein binding, 0.22-μm filterh as each was transferred into a sterile empty vial. All solutions were prepared at room temperature (≈25 °C) in a level 4 sterile environment.