Stability of cefpirome sulfate in the presence of commonly used intensive care drugs during simulated Y-site injection.

The stability of cefpirome sulfate during simulated Y-site injection with drugs commonly used in the intensive care unit was studied. Cefpirome sulfate was constituted and diluted to 50 mg/mL with 0.9% sodium chloride injection, 0.45% sodium chloride injection, 5% dextrose injection, and lactated Ringer's injection. Each cefpirome sulfate solution was mixed 1:1 (simulating Y-site injection) with amikacin 5.0 mg/mL (as the sulfate salt), amphotericin B 0.1 mg/mL, cefazolin 10 mg/mL (as the sodium salt), clindamycin 12.0 mg/mL (as the phosphate ester), dexamethasone phosphate 4.0 mg/mL (as the sodium salt), dopamine hydrochloride 0.8 mg/mL, epinephrine 0.1 mg/mL (as the hydrochloride salt), fluconazole 2.0 mg/mL, gentamicin 1.0 mg/mL (as the sulfate salt), and vancomycin 5.0 mg/mL (as the hydrochloride salt). All the drug combinations were prepared in triplicate and maintained at 23 degrees C. The combinations were observed visually at intervals up to eight hours, pH was measured, and samples were tested for drug concentration by high-performance liquid chromatography. Cefpirome was stable in the presence of each of the secondary drugs throughout the study period. All the secondary drugs except amphotericin B were stable in the presence of cefpirome. There were no visual phenomena indicating incompatibility. Changes in pH were minimal. Cefpirome 50 mg/mL (as the sulfate salt) in four different diluents was stable in the presence of each of 10 commonly used intensive care drugs for at least eight hours during simulated Y-site administration. Amphotericin B 0.1 mg/mL was not stable in the presence of cefpirome sulfate.