Background Pharmaceutical care might help optimise antibiotic use. However, assessing the influence of pharmacy interventions in the management of antimicrobials is not easy, and results from different studies reveal somewhat contradictory results.

Purpose To evaluate the impact of pharmacist interventions on antibiotic use and their economic impact in medical patients of a tertiary teaching institution.

Materials and methods Inclusion criteria: patients over 18 years old admitted to the internal medicine unit who had a course of antibiotics during their admission. Timeframe: June–July 2013. During the ward round in this area, on a daily basis, prescriptions were validated by the pharmacist, following antimicrobial institutional guidelines. Issues were discussed with the prescriber and the microbiologist, if necessary. Pharmacist’s interventions were divided into: (1) inappropriate or non-approved indication, (2) higher or lower dose, (3) inappropriate dosing interval, (4) longer courses in the absence of continuing infection, and (5) timely conversion from intravenous to oral therapy, whenever possible.

Results Demographics: 257 patients included, mean age = 73.4 years-old,%female = 41%. Overall interventions: 25 out of 257 (9.72%), sorted as follow: (1): 7 interventions (carbapenem and linezolid not indicated in 6 and 1 cases, respectively), (2): 6 overdoses in renal patients, (3): 0, (4): 4, and (5): 7 interventions. Acceptance rate: 84%. Total cost saving: 2,966 €.

Conclusions Pharmacist interventions, interacting directly with the physicians at ward level, could play an important role in optimising antibiotic use. Approximately one out of ten antimicrobial prescriptions needed changing. On average, Pharmacy interventions on antimicrobials generated savings close to €1,500 per month. De-escalation or switching from a carbapenem (prescribed in a non-permitted indication) to other non-restricted antibiotics, overdose in renal patients, and switching from intravenous to oral therapy were the most common among patients of our institution.

No conflict of interest.