Cefamandole pharmacokinetics and dosage adjustments in relation to renal function

The pharmacokinetic characteristics of cefamandole were determined after intravenous administration of a 1-Gm dose to 10 subjects with normal renal function, 10 patients with stabilized renal failure, and five chronic nephritic patients included in a intermittent hemodialysis program. In normal subjects, biological half-life (t1/2) averaged 0.94 hour, the overall elimination rate constant (Ke) was 0.7378 (hr-1), total clearance (Ct) was 223 ml/min/1.73 m2, renal clearance (Cr) was 164 ml/min/1.73 m2, and urine recovery of cefamandole over the 6 hours following a dose amounted to 74 per cent of the administered dose. In patients with stabilized renal failure and in patients on hemodialysis, biological half-life was markedly increased, with a theoretical value of 10.4 hours in case of a creatinine clearance of zero. The amount of antibiotic extracted over a 6-hour dialysis period accounted for 29 per cent of the cefamandole present in the vascular compartment at the beginning of the dialysis procedure. A significant correlation was established between the values of Ke and creatinine clearances, Ccr: Ke = 0.0289 + 0.0063Ccr (r = 0.937). This relationship was used to calculate the loading dose (LD), maintenance doses (D), and dosage intervals (tau) with regard to renal function. From these data recommendations regarding the adjustment of cefamandole dosage to the renal status can be made.