Doripenem 5 mg/mL in 5% dextrose injection or in 0.9% sodium chloride injection was physically compatible for four hours at room temperature with 75 drugs during simulated Y-site administration. Three drugs combined with doripenem in 5% dextrose injection or 0.9% sodium chloride injection and 7 drugs combined with doripenem in 0.9% sodium chloride injection resulted in unacceptable precipitation or an increase in measured haze and should not be simultaneously administered with doripenem admixtures.