Optimal perioperative flomoxef administration interval in hepatobiliary-pancreatic surgery

To clarify the optimal perioperative prophylactic flomoxef (FMOX) interval. Perioperative prophylactic antimicrobials are readministered at intervals of twice their half-life. However, the actual concentrations of antimicrobial agents and the degree of accumulation have not been determined. FMOX, also known as oxacephem, is a β-lactam antibiotic with broad-spectrum antibacterial activity against gram-positive and gram-negative aerobic and anaerobic bacteria. Serum concentrations were evaluated in patients who underwent hepatobiliary-pancreatic surgery between April 2019 and December 2020 and received an additional dose of FMOX every 3 h or 5 h during the surgical procedure based on their renal function. Among the 31 patients (Table), 25 (with creatinine clearance [Ccr] >60 mL/min in 18 and ≤60 mL/min in 7) and 6 (Ccr ≤60 mL/min) received FMOX every 3 h and 5 h, respectively. Of the 25 patients with a creatinine clearance (Ccr) >60 mL/min, 18 had serum FMOX concentrations of 9.56 ± 2.60 mg/L and 9.98 ± 2.99 mg/L (p = 0.07). For the 7 patients with Ccr ≤60 mL/min, serum FMOX levels were 16.70 ± 6.63 mg/L and 21.83 ± 7.95 mg/L (p < 0.01), respectively. When comparing FMOX dosing intervals, median concentrations were 9.85 mg/L (Ccr >60 mL/min) at 6 h, compared to 12.85 mg/L at 6 h and 20.03 mg/L (Ccr ≤60 mL/min) at 5 h for Ccr ≤60 mL/min, respectively (Fig. A, B). Administering FMOX every 3 h when Ccr ≥ 60 mL/min and every 5 h when Ccr < 60 mL/min is appropriate.