Pharmacokinetics of cefamandole in the presence of renal failure in patients undergoing hemodialysis

Clinical pharmacokinetics of antibiotics in patients with impaired renal function

Many antibiotics are eliminated renally and dosage adjustments are commonly made in patients with renal insufficiency. This is a critical review of antibiotic pharmacokinetics in patients with various degrees of renal function. Detailed information regarding pharmacokinetic alterations with specific antibiotics or antibiotic classes has been compiled and tabulated. From pharmacokinetic evidence, recommendations for dosage adjustments of antibiotics are supplied. The criteria used for assigning rating levels to specific pharmacokinetic articles as well as the grading system for dosage adjustments are outlined. In addition, a basic review of pharmacokinetic alterations in renal failure and factors affecting the removal of drugs by haemodialysis is included.

Disposition kinetics of cefamandole during continuous ambulatory peritoneal dialysis

Cefamandole disposition kinetics were examined in six male subjects with renal impairment who were undergoing continuous ambulatory peritoneal dialysis. Creatinine clearance values ranged from less than 1 to 11 ml/min. Cefamandole was given as a 1-g intravenous dose infused over 30 min. Cefamandole concentrations were determined in serum, urine, and dialysis fluid by a high-performance liquid chromatographic method. The following average parameter values were obtained (range): half-life, 6.1 h (4.6 to 9.7); systemic clearance, 21.9 ml/min (8.4 to 35.5); renal clearance, 11.5 ml/min (0.03 to 22.3); dialysis clearance, 0.92 ml/min (0.7 to 1.3); nonrenal clearance, 12.2 ml/min (2.9 to 27.0); volume of distribution, 0.18 liter/kg (0.09 to 0.25); steady-state volume of distribution, 0.17 liter/kg (0.09 to 0.24). Approximately 5% of the dose was dialyzed (range, 2.8 to 8.3), indicating that there is no need to supplement a dosing regimen of cefamandole due to loss by dialysis. There was a positive correlation between creatinine clearance and the terminal elimination rate constant of cefamandole (r2 = 0.41) and cefamandole renal clearance (r2 = 0.83).

Differences in kinetic properties of drugs: implications as to the selection of a particular drug for use in patients with renal failure with special emphasis on antibiotics and beta-adrenoceptor blocking agents

Adjustment of dosage of a renally excreted drug (or active metabolite) for patients with severe renal failure still causes some difficulties. It is therefore helpful to select, within a given therapeutic group of drugs, a compound that is particularly safe and easy to use and, if possible, does not require adjustment of dosage. This is 'the drug of choice for renal patients'. Such a drug would ideally meet the following pharmacokinetic criteria: normal urinary excretion less than 30% of the administered dose, predominant biliary and intestinal removal, disposition essentially unaffected by parameters likely to be modified in renal failure (e.g. changes in serum proteins or fluid compartments: receptor sensitivity, etc), and pharmacokinetics not complicated by the formation of active or toxic metabolites that depend on urinary elimination. Above all, the drug should have a wide therapeutic margin and must be free of nephrotoxicity. Examples of drugs of choice for patients with impaired renal function are given for some important therapeutic groups and special emphasis is placed on antibiotics and beta-adrenoceptor blocking agents.

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.

Clinical use of cefamandole: a new cephalosporin

Cefamandole, a new cephalosporin derivative, has been used in treatment of six patients who had diminished renal function and respiratory infections, and of 14 patients with urinary tract infections (UTI). Infection was eliminated in all patients with respiratory infections, and in seven of the patients with UTI. No serious side effects were encountered and, even in patients with pre-existing renal dysfunction, no reduction in renal function occurred.

Therapy of serious infections with cefamandole

Forty-four patients with serious bacterial infections were treated with cefamandole in a dose 1--2 g every four to six hours. Thirty-two patients were cured and six were markedly improved. Three of six failures were due to superinfection with cephalothin-resistant microorganisms. The over-all bacteriologic response was 80%. In 12 of 13 patients with bacteremia the blood was sterilized. Ten of 14 patients with gram-negative bacillary infections responded to treatment. Six of these were due to cephalothin-resistant microorganisms, three of which responded. Fifteen patients who were treated had a history of penicillin allergy. There were no serious reactions although skin rash did develop. Phlebitis was uncommon.