Background Mid-year supply problems of piperacillin/tazobactam (PT) led the Spanish Agency for Medicines and Health Products (AEMPS) to define a proposal to manage the approaching situation. AEMPS proffered some guidelines depending on the type of infection addressed and the priority of use according to the case.

Purpose To analyse patients under PT treatment focusing on drug indication and infection features. To evaluate the prescription adequacy and treatment duration.

Material and methods Retrospective observational study (June and July 2017), including all patients who received PT, was conducted. The study variables were: demographics, clinical services, initial severity (no sepsis, sepsis or septic shock), origin of infection and acquisition (community- or healthcare-related), therapy type (empiric or targeted), treatment duration, evaluation on day 0 and global evaluation (adequate, not recommended, inadequate or unnecessary). The variables were obtained from the medical records. The results are expressed as frequency measurements (%).

Results Twenty-two patients were included: 40.9% were male and 59.1% were female. Age distribution was: 18.2%<60 years’ old, 50% 60–80 years’ old and 31.8%>80 years’ old. Internal medicine was the main prescribing service (59. 1%). No sepsis was observed in 40.9% of patients, sepsis in 36.4% and septic shock in 13.6%. Origin of infection distribution was: 27.3% skin and soft tissue, 18.2% intra-abdominal and 13.6% urinary tract. Most of the infections were community-related (59.1%). Therapy was basically targeted (63.6%) and lasted a median of 9 days. Therapy evaluation at day 0 versus global evaluation showed: 19 vs 12 adequate, 2 vs 4 not recommended, 0 vs 3 inadequate and 1 vs 2 unnecessary.

Conclusion In accordance with AEMPS’ proposal and clinical guidelines, almost every treatment (86.4%) was initially adequate, meaning acceptable antibiotic indication. Global evaluation, in contrast, showed that 36.8% of that proportion of patients was not adequate at the end of treatment, revealing prescribing faults that may be solved by considering treatment duration and de-escalation, especially when there is no other way to address shortage situations.

No conflict of interest