Pharmacokinetics of Ceftriaxone During Prolonged Intermittent Renal Replacement Therapy in a Patient with Child–Pugh B Cirrhosis and Ascites

Prolonged intermittent renal replacement therapy (PIRRT) is emerging as an alternative to continuous renal replacement therapy as renal support for the critically ill. Unfortunately, dosing data are lacking for many antibiotics, including ceftriaxone. To allow clinicians to prescribe ceftriaxone effectively and safely in this setting, an understanding of the effects of PIRRT on the plasma pharmacokinetics (PK) of ceftriaxone is required. In this case, the authors describe the PK of ceftriaxone in a critically ill patient on PIRRT for the treatment of presumed spontaneous bacterial peritonitis. Blood samples were taken over two dosing intervals: one during PIRRT, and the other off PIRRT. A one-compartment PK model was used to describe ceftriaxone PK; little difference in clearance was noted with and without PIRRT. The authors suggest that ceftriaxone at a dose of 2g qd during PIRRT therapy is adequate to maintain serum levels above the minimum inhibitory concentrations for likely pathogens of non-central nervous system infections in critically ill patients.