Pharmacy Services

Ceftolozane / Tazobactam (Zerbaxa) Vial and Carton Label Confusion Leads to Errors

May 22, 2015

Unconventional labeling of the drug dose on the vial and carton labels has led to dispensing errors with ceftolozane / tazobactam. Ceftolozane / tazobactam is an intravenous combination antibiotic labeled to treat complicated urinary tract infections and complicated intraabdominal infections in adults. The original vial and carton labels described the vial contents in terms of the individual drug components (ceftolozane / tazobactam for injection 1 g/0.5 g per vial). The labels did not include the total combined dose of ceftolozane / tazobactam 1.5 g. This led to confusion since dosing recommendations for ceftolozane / tazobactam are made primarily in terms of the combined dose. Also, the convention most pharmacists are used to seeing for similar combination antibiotic products is the combined dose highlighted on the label. There are 7 known cases of dispensing errors since the December 2014 approval of ceftolozane / tazobactam. Up to 50% more drug was dispensed than was prescribed in these cases due to confusion between the vial label and the prescribed dose. No adverse drug reactions were reported in these cases.

FDA published a drug safety communication regarding dosing errors with ceftolozane / tazobactam. The manufacturer also revised the vial and carton labels highlighting the combined dose of ceftolozane / tazobactam 1.5 g. The individual drug amounts are still included on the label, but in smaller, less obvious text. This revised labeling is more consistent with the labeling of other combination antibiotics (eg, ampicillin / sulbactam). Be alert when dosing and dispensing ceftolozane / tazobactam that the intended dose matches the dispensed dose in terms of the individual constituents and combined dose.

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Updated
May 22, 2015; University of Utah, Drug Information Service. Copyright 2015, Drug Information Service, University of Utah, Salt Lake City, UT.