Comparison of the pharmacokinetics of cefamandole and other cephalosporin compounds.

The pharmacokinetic properties of cefamandole were determined and compared with the properties of other cephalosporin agents. Cefamandole was found to be approximately 70% bound to protein. The mean peak concentration in serum after intramuscular (im) injection of 1 g of cefamandole was 20 microgram/ml at 0.5 hr, whereas the level at 6 hr was 1 microgram/ml. After intravenous (iv) infusion of 1 g of cefamandole, levels in serum ranged from 68 to 147 microgram/ml depending on the period of infusion. At 4 hr after infusion, levels were less than 1 microgram/ml. Probenecid elevated serum levels and prolonged excretion. The half-life (t1/2) of cefamandole after im injection ranged from 1 to 1.5 hr and from 0.45 to 1.2 hr after iv injection. Rates of serum and renal clearance of cefamandole ranged from 210 to 300 microliter/min per 1.73 m2. The apparent volume of distribution ranged from 12.4 to 17.9 liters/1.73 m2. Urinary excretion was rapid, with 60% of a dose excreted in the first 2 hr after injection. In 6 hr 90% of a dose was excreted. The pharmacokinetic properties of cefamandole were similar to those of cephalothin and cefoxitin, but the serum t1/2 was shorter than that reported for cefazolin and cefuroxime. Correlation of in vitro studies with pharmacokinetic properties revealed that cefamandole would inhibit most susceptible gram-positive and gram-negative bacteria if given by suggested im or iv regimens.