5PSQ-028 The hospital pharmacist facing the national aztreonam shortage

<h3>Background and Importance</h3> Aztreonam is a beta-lactam antibiotic used for urinary, respiratory and systemic infections caused by gram-negative bacteria (GNB) with no other alternatives and/or in patients allergic to penicillins. <h3>Aim and Objectives</h3> To analyse aztreonam prescriptions, identifying therapeutic alternatives to optimise its use during the national shortage. <h3>Material and Methods</h3> Observational and retrospective study (April 2024 to August 2024). All prescriptions with aztreonam were analysed. The following variables were collected: age, sex, medical service, indications, empirical/directed treatment (isolated microorganism), duration, pharmaceutical intervention. Data were analysed with Excel. <h3>Results</h3> Aztreonam was prescribed in 49 patients with a median age of 68 (23–91) years; 24 males (48.9%). Thirty-nine percent of the prescriptions were in Internal Medicine, followed by General Surgery (14%). The most frequent indications were urinary tract infection (22%), skin and soft-tissue infections (18%), respiratory infections (16%), intra-abdominal infections (16%), and sepsis (16%). The mean duration of treatment was 11 (2–21) days. The 10% were treatments directed against metallo-betalactamase-producing BGC, identifying NDM carbapenemase-producing <i>Enterobacter cloacae</i> (N=6), IMP carbapenemase-producing <i>Pseudomonas aeruginosa</i> (N=4), BLEE-producing <i>Klebsiella pneumoniae</i> (N=3), NDM carbapenemase-producing <i>Escherichia coli</i> (N=1), another unidentified gram-negative (N=1). <h3>Fourteen prescriptions were authorised: </h3> 10 for multidrug-resistant GNB and four for confirmed allergy. In 35 cases, alternatives were identified, 15 after ruling out false allergy, and in the other 20, the pharmacist proposed therapeutic alternatives, which were accepted. <h3>Conclusion and Relevance</h3> The review of aztreonam prescription by the pharmacist optimised the use of aztreonam, reducing authorisations to 28%, making it possible to identify false allergies (78% of patients labelled as allergic to penicillins) and prioritising its use in situations without alternatives. 100% of the pharmaceutical interventions carried out were accepted by the prescribing physician. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest