Background and importance The introduction of the unit dose (DU) as a drug dispensing system produces a multiplicity of advantages, ranging from prescribing to administering therapies.

Aim and objectives The purpose of this study was to evaluate, through the computerised prescription, the prescriptive appropriateness of antibiotic therapy and the economic impact of a targeted therapy after an antibiogram compared with empirical therapy.

Material and methods The analysis was carried out by extrapolating, from the prescription software and administration in use, the antibiotic prescriptions subjected to a single request motivated (SRM) from 1 January 2019 to 31 December 2019. With the Modulab software, a clinical information management system, prescriptions with antibiograms were verified and divided into appropriate and inappropriate. Prescriptions initiated as empirical therapies were defined as appropriate if the results of the antibiogram confirmed the therapy already started or if the prescriptions changed following the antibiogram. Therapies were considered inappropriate if the antibiogram results were different from the antibiotics used as empirical therapy (resistant/intermediate) or were not tested.

Prescriptions were grouped for empirically prescribed antibiotics and for sensitive antibiotics (as a result of the antibiogram), considering a median duration of therapy. The maximum daily dosage from the technical data sheet was considered for the calculation of the cost of the therapy. Only inappropriate prescriptions were considered in the pharmacoeconomic evaluation.

Results During the study period, total prescriptions of antibiotics with SRM were 2067 of which 1322 (64%) had no antibiogram and 745 (36%) had an antibiogram. The latter were divided into appropriate (63%) and inappropriate (37%). The pharmacoeconomic analysis showed a cost of non-appropriate therapy of 53 950€, with a possible saving of around 49 274€ if the same had been transferred to the sensitive antibiotic resulting from the antibiogram.

Conclusion and relevance We hope, in the future, to directly consult the antibiogram from the computerised prescription to highlight extemporaneously the limitations of long term empirical therapies both for prescriptive appropriateness and for cost savings.

Conflict of interest No conflict of interest