The 2013 joint clinical practice guidelines from the American Society of Health-System Pharmacists (ASHP), Infectious Diseases Society of America (IDSA), Surgical Infection Society (SIS), and Society for Healthcare Epidemiology of America (SHEA) emphasize several important factors when planning antimicrobial prophylaxis for surgery. Patients who are already receiving antibiotics for a remote or ongoing infection should still be given prophylactic antibiotics prior to surgery to ensure that drug levels in the blood and tissues are sufficient to cover the pathogens most likely to cause surgical site infections throughout the operation. If the antibiotics being used for treatment are appropriate for surgical prophylaxis, then giving an additional dose within 60 minutes of the surgical incision is considered adequate. If they are not appropriate, then the prophylactic regimen recommended specifically for the planned procedure should be administered. [1]

The authors of a 2024 StatPearls article on preoperative antibiotic prophylaxis similarly state that if a patient is already receiving an antibiotic for another infection prior to surgery and that agent is appropriate for surgical prophylaxis, an additional dose of the same antibiotic can be given within 60 minutes before the surgical incision. The article notes this recommendation, but unfortunately does not provide a specific supporting reference to justify this guidance. [2]

A 2024 retrospective study examined preoperative antibiotic practices at a single hospital over one month (November 2022) to quantify the redundancy of prophylactic antibiotics in patients already receiving therapeutic antimicrobials. The background notes that initiatives such as the Surgical Infection Prevention (SIP) project and the Surgical Care Improvement Project (SCIP) were established to reduce postoperative surgical site infections (SSIs) by standardizing quality measures, including the timing, selection, and duration of prophylactic antibiotics. Despite these programs and guidelines from the ASHP and the IDSA, patients already on antibiotics for the condition requiring surgery were often also prescribed additional prophylactic antibiotics. Of 92 surgeries meeting inclusion criteria, 38 cases (41.3%) involved patients who had received therapeutic antibiotics for more than 24 hours before surgery, including laparoscopic cholecystectomy, appendectomy, wound debridement, and soft tissue incision and drainage. The study concluded that these findings represent an opportunity to strengthen antimicrobial stewardship programs, including physician education and allowing pharmacy intervention to prevent unnecessary and redundant preoperative antibiotic use. [3]

A 2021 retrospective, descriptive chart review study focused on the utilization of perioperative antimicrobial prophylaxis in patients already receiving antibiotic therapy for active infections. The primary endpoint assessed the rate of duplicative antibiotic therapy (DAT), characterized by the administration of prophylactic antibiotics with similar or narrower bacterial coverage within the dose interval of the treatment antibiotics. In total, 158 patients were analyzed, with 44.3% receiving DAT and 55.7% not receiving additional prophylactic antibiotics. Results revealed no significant differences in the rates of SSI, Clostridium difficile infection, or acute kidney injury (AKI) between the two groups. However, a numerical increase in postop AKI incidence was noted in the DAT group (12.9% compared to 5.7% in the non-DAT group), raising concerns about potential adverse effects. The findings from this research indicate that while duplicative prophylactic antibiotic use is prevalent, it may not significantly reduce SSI rates but could potentially contribute to higher adverse event risks, emphasizing the need for further investigation and potential refinement of antimicrobial stewardship practices. Of note, this study is currently available only as a preprint and has not been peer reviewed. [4]