Background
The application of Antimicrobial Stewardship (AMS) principles may entail increased cost to allow for narrower-spectrum therapy. Prescribing of benzylpenicillin (BP) and ceftriaxone (CRO) for Outpatient Parenteral Antimicrobial Therapy (OPAT) demonstrates the complex challenge of this principle. The aim of this study is to analyse the use of BP and CRO in our OPAT program including indications and relative cost.
Methods
We analysed all adult patients on our OPAT program who received intravenous BP or CRO over one year. We identified a ‘cross-over’ group of patients who could have received either agent. Economic comparison was based on acquisition cost of the therapy (drug, infuser and preparation costs).
Results
Of 105 eligible patients, 54(51%) received BP and 51(49%) received CRO. Forty (38%) patients were suitable for either agent, of these, the majority (31, 78%) were treated with BP. Economic analysis demonstrated the average daily cost of BP therapy was $93.76AUD/day compared with $1.23AUD/day for CRO. Thus, across our OPAT programs we had an additional average cost of $92.53AUD/patient/day to use BP instead of CRO. Program-wide the annual additional cost of using BP, and thus applying this AMS strategy, was $68,386.12 AUD.
Conclusion
BP is often selected over CRO by clinicians where possible as recommended by the Australian guidelines; however, BP is associated with higher daily acquisition costs. More broadly, a number of narrower spectrum agent may involve a significantly higher cost than comparators, the $92.53 cost/day to prevent CRO exposure, can be considered when applying other antimicrobial-substitution AMS interventions in an acute healthcare setting.