Background This study was performed in a medium-sized public hospital of 460 beds, which supports the 150,000 inhabitants. Until August 2010, only restricted--use antibiotics were distributed as unit doses; the rest were distributed in bulk. Since September 2010 all antibiotics have been administered as unit doses per patient.

Purpose To evaluate the effect of this intervention on antibiotic administration.

Material and methods We investigated the amount of antibiotics used, expressed in DDDs/100 patient-days, for the years 2009 and 2011. Antibiotics were classified according to the ATC system, excluding J05, J06 and J07. The mean amounts administered the first year and the other year were tested for statistical significance using the paired-sample t test. Difference in use for each antibiotic were tested by the Bonferroni t test.

Results In total, in 2009 71 antibiotics were used (153.28 DDDs/100 patient-days) while in 2011 64 (145.31 DDDs/100 patient-days): mean difference was not statistically significant (t = 0.78, p = 0.44). 36 antibiotics were administered in both years (mean difference in DDDs/100 patient-days: 0.38, statistically significant, t = 2.91, p = 0.0063). In 16 of these antibiotics, the use of which was more than 1 DDD/100 patient-day, the mean difference was not statistically significant (difference: 0.69, t = 2.56, p = 0.22). When the Bonferroni t test was applied for each antibiotic, a statistically significant difference was observed for 6 infrequently prescribed antibiotics (DDD/100 patient-day < 1): erythromycin, phenoxymethylpenicillin, streptomycin, ketoconazole, ofloxacin and benzathine benzylpenicillin.

Conclusion Unit dose intervention led to a reduction in the use of specific antibiotics, although it did not prove statistically significant for antibiotics of DDD/100 patient-day > 1. A significant difference was only observed in infrequently prescribed antibiotics, which could be justified by the small number of patients. Nevertheless, all antibiotics are still distributed in a unit dose system in hospitalised patients as it contributes decisively to pharmaceutical patient care and records.

References and/or acknowledgements No conflict of interest.