Stability of cefepime and metronidazole prepared for simplified administration as a single product

The stabilities of cefepime and metronidazole were determined after preparation of a single admixture product in view of its potential use as a simple and cost-effective therapeutic alternative for infections caused by many aerobic and anaerobic pathogens. The stability of cefepime 1000 or 2000 mg mixed with metronidazole 500 or 1500 mg was evaluated via high-performance liquid chromatography after storage for up to 336 h at 4 or 23 °C. Cefepime was stable in all 4 °C samples for up to 336 h, retaining ≥95% of initial concentrations. Samples of cefepime 1000 and 2000 mg mixed with metronidazole 500 mg were stable at 23 °C for up to 48 h, whereas those mixed with metronidazole 1500 mg and cefepime controls were stable at 23 °C for up to 72 h. Metronidazole was stable in all samples for up to 336 h, retaining ≥94% of initial concentrations. These data suggest that therapeutic use of cefepime and metronidazole as a single intravenous admixture product is feasible and practical.