Pharmacokinetics and dosage planning of cefozopran in patients with renal insufficiency

We investigated pharmacokinetics of cefozopran (CZOP), a new cephem antibiotic, in patients with renal insufficiency. Serum levels of CZOP after a single administration were assayed by HPLC and urinary levels by Bioassay. 1) 1.0g CZOP were administered to healthy volunteers and patients with varying degrees of impaired renal function by 30minutes drip infusion. Pharmacokinetic parameters were determined using a two-compartment model. In healthy volunteers, the mean values of T_1/2 (β) was 2.20h and β was 0.321/h. As proceeded the renal insufficiency, T_1/2 (β) was prolonged and β was decreased. The mean urinary excretion rate within 24h was 70.0% in healthy volunteers and decreased to 32.5% in Patients with severe renal insufficiency whose creatinine clearrance (Ccr) were below 30ml/min. 2) To plan a regimen, β was selected as the parameter which varied in accordance with the degree of impaired renal function as measured by Ccr. A recommended dosing regimen in patients with renal insufficiency was studied.