Background The objective of preoperative antibiotic prophylaxis (PAP) is to reduce the incidence of postoperative wound infection. In our centre, the pharmacy service is actively involved in the PAP antibiotic aseptic compounding in the centralised intravenous admixture unit. The PAP is prepared according to the approved infectious disease commission protocol that is reviewed by the pharmacist and applied for each patient the day before elective surgery. A systematic review of documented allergies has also been implemented since April 2015.

Purpose To evaluate the proportion of detected patients who required PAP with no notified antibiotic allergies in the preoperative patient list, the drugs implicated and pharmaceutical interventions.

Material and methods Descriptive, observational and retrospective study. According to the allergy detection programme, a pharmacist reviewed if the allergies had been notified by the surgeon in order to select appropriate alternative, if needed. Also, pharmacists checked previous patient medical records in order to detect documented allergies that were not notified. When detected, the pharmacist proposed an alternative antibiotic regimen.

Data regarding the programme results and pharmacist interventions between April 2015 and September 2015 were analysed.

Results 1929 (33.7%) patients received PAP from 5724 elective surgeries. 64 patients who received PAP (3.3%) were allergic to antibiotics, had not been notified and required pharmaceutical interventions. 82.8% of unnotified allergies were to β-lactams, 4.7% to aminoglycosides, 6.3% to β-lactams and aminoglycosides, and 6.2% to others, including clavulanic acid intolerance. 57 (89.1%) of antibiotic prophylaxis prescriptions were changed due to an unnotified allergy. More frequent proposed alternative regimens were: intravenous vancomycin as an alternative to intravenous cefazolin (40.6%), moxifloxacin ophthalmic solution to intracameral cefuroxime (15.6%) and the combination of intravenous gentamicin and intravenous clindamycin to intravenous amoxicillin-clavulanate (12.5%).

Conclusion A significant proportion of unreported allergies in the preoperative patient list, especially to β-lactams, were detected. Pharmaceutical interventions prevented the error and possible collateral damage. Allergies notification is an improvement approach to guarantee patient safety.

No conflict of interest.