Ceftazidime-avibactam (CAZ-AVI) is a combination of ceftazidime and avibactam at a fixed ratio of 4:1 and was approved for the treatment of serious infections caused by resistant Gram-negative pathogens [1]. The most common adverse reactions of CAZ-AVI were diarrhea, nausea, headache, vomiting, and pyrexia [2]. The pharmacokinetic parameters of CAZ-AVI (CAZ 2000 mg + AVI 500 mg) in healthy subjects were investigated [3] and the maximum plasma concentration (Cmax) of ceftazidime was 113.0 ± 15.3 mg/L, the elimination half-life (t1/2) 1.7 ± 0.1 h, the area under the concentration-time curve (AUC) 348.2 ± 17.2 mg h/L, clearance (CL) 5.7 ± 17.2 L/h. The Cmax of avibactam was 15.0 ± 20.6 mg/L, t1/2 1.4 ± 0.1 h, AUC 42.2 ± 14.4 mg h/L, CL 11.9 ± 14.4 L/h. Dosage should be adjusted according to renal function. However, the dose regimen for patients with renal replacement therapy (RRT) is absent in the label inserts. Up to now, the articles about CAZ-AVI in patients undergoing RRT were limited to 3 patients receiving continuous renal replacement therapy (CRRT) and 1 patient receiving intermittent hemodialysis (IHD) [[4], [5], [6]].

Prolonged intermittent renal replacement therapy (PIRRT) is a hybrid therapy that provides RRT for an extended period but on an intermittent basis. PIRRT is becoming the mainstay of renal support for critically ill patients with acute kidney injury [7]. PIRRT, IHD, and CRRT are different treatments for renal replacement therapy [8]. So far, there are still no data for CAZ-AVI in patients undergoing PIRRT. Here we explored a dosing regimen for CAZ-AVI and a scheduled time for hemodialysis in a critically ill patient needing RRT, and presented a 6h-PIRRT session beginning 12h after CAZ-AVI (1.875g q24h) dosing every other day (Fig. 1B).