Ceftolozane-Tazobactam Pharmacokinetics in a Critically Ill Patient on Continuous Venovenous Hemofiltration.

Extended-infusion ceftolozane-tazobactam treatment at 1.5 g every 8 h was used to treat multidrug-resistant Pseudomonas aeruginosa in a critically ill patient on continuous venovenous hemofiltration. Serum drug concentrations were measured at 1, 4, 5, 6, and 8 h after the start of infusion. Prefilter levels of ceftolozane produced a maximum concentration of drug (Cmax) of 38.57 μg/ml, concentration at the end of the dosing interval (Cmin) of 31.63 μg/ml, time to Cmax (Tmax) of 4 h, area under the concentration-time curve from 0 to 8 h (AUC0-8) of 284.38 μg · h/ml, and a half-life (t1/2) of 30.7 h. The concentrations were eight times the susceptibility breakpoint for the entire dosing interval.