The total process cost of parenteral antibiotic therapy: beyond drug acquisition cost

Intravenous antibiotic therapy represents a considerable expense to hospital pharmacy budgets; however, when evaluating the cost of these therapies one needs to look beyond acquisition cost and consider the total "process" cost of treatment. These additional costs include the personnel time and the materials required for drug preparation and administration, maintenance of intravenous access, waste disposal, and therapeutic drug monitoring. This paper provides an examination of the daily process costs of intravenous therapy with cefazolin, cefotaxime, ceftazidime, once-daily ceftriaxone, cefuroxime, or aminoglycoside (tobramycin or gentamicin) combination therapy, where the aminoglycoside is given once daily or in divided doses. This analysis demonstrates that the costs associated with drug preparation and administration can equal or exceed drug acquisition costs and are highly dependent on dosing frequency. On this basis, ceftriaxone, at $52.21, is the least expensive of these antibiotic regimens in terms of total daily process cost, followed by the remaining cephalosporins at $53.29 to $94.57, aminoglycoside once-daily combinations at $93.44 to $99.65, and aminoglycoside multidose combinations at $103.26 to $111.42, respectively (values are given in constant 1995 Canadian dollars). Once-daily ceftriaxone offers the potential for cost savings compared with other antibiotic regimens whose pharmacokinetics require multiple daily doses, due largely to the reduced resources required for ceftriaxone preparation and administration.