The Cephalosporins

Abstract

Cephalothin and cephaloridine, semisynthetic congeners of cephalosporin C, are highly active against nearly all Gram-positive bacteria (except enterococci and methicillin-resistant staphylococci) and, at concentrations of 1µg to 10 µg/ml, against most strains of Salmonella, Shigella, Klebsiella, Proteus mirabilis, and many Escherichia coli, paracolon bacteria, and Hemophilus influenzae. These drugs are inactivated by a beta lactamase, cephalosporinase, and are susceptible to very high concentrations of penicillinase. They inhibit cell wall synthesis. Neither cephalothin or cephaloridine is absorbed from the gastrointestinal tract. Two related compounds, cephaloglycine and cephalexin, are absorbed by this route. They are largely excreted by the kidneys. In the presence of renal disease the dose of each must be reduced. Cross-sensitization between penicillin and the cephalosporin C congeners is very uncommon and is not an important contraindication to the use of these agents in individuals allergic to penicillin. Cephalothin may produce Coombs-positive reactions. Doses of cephaloridine greater than 4 g/day may lead to a varying degree of renal dysfunction or acute tubular necrosis. Fever, eosinophilia, anaphylaxis, serum sickness, and various skin rashes occur in about 5% of treated patients. The usefulness of cephalothin and and cephaloridine in the management of a variety of infections is well established.