Evaluation of cefaclor.

The chemistry, pharmacology, pharmacokinetics, bacterial spectrum, clinical use, dosage, adverse reactions, and dosage forms and cost of cefaclor are reviewed. Cefaclor, a congener of cephalexin monohydrate, is a new semisynthetic cephalosporin antibiotic. It is well absorbed when given orally on an empty stomach; absorption is delayed by the presence of food. Although metabolism may play a role in the disposition of cefaclor, elimination is primarily renal. Cefaclor's spectrum of activity is similar to that of cefalexin, including a wide range of gram-negative and gram-positive bacteria; in particular, Escherichia coli, Klebsiella spp., Proteus mirabilis, Salmonella spp., and Haemophilus influenzae are more susceptible to clinically achievable concentrations of cefaclor than cephalexin. Cefaclor has been demonstrated to be effective against beta-lactamase-producing H. influenzae resistant to ampicillin, but further studies are needed to establish the clinical significance of this activity. Efficacy of cefaclor has been demonstrated in urinary tract, upper and lower respiratory tract, and skin and soft tissue infections in adults and children as well as in pediatric otitis media. Adverse reactions, mostly gastrointestinal, are generally mild and occur in few patients. Usual doses are 250-500 mg every eight hours in adults and 20--40 mg/kg/day in children, although this pediatric dose may be two low for otitis media. Clinical superiority of cefaclor over less expensive antibiotics has not been demonstrated.