Cefaclor Hydrate

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.

We review the discovery and development of the cephalosporins and subsequently cefaclor. Cefaclor is active against a wide range of commonly encountered bacterial pathogens, acting by inhibiting cell wall synthesis. Its in vitro activity compares favourably with other beta-lactam antibiotics. Its pharmacokinetic properties indicate that an 8-hourly dosing schedule is appropriate. In addition a delayed release formulation allowing twice daily dosage has been developed. The efficacy of both formulations of cefaclor has been verified by many clinical trials. Cefaclor has been widely used in infections of the respiratory tract (including otitis media), urinary tract and soft tissues. The results of therapy are summarized. The low incidence of adverse events is highlighted and the beneficial influence of this on compliance is described. Finally, the pharmaco-economics of cefaclor are considered.

Cefaclor is a well-absorbed oral cephalosporin antibiotic. Peak concentrations in serum are attained within 30-60 minutes. Food intake reduces the rate, but not the extent of absorption. Cefaclor is not metabolized to a significant degree, but it degrades chemically in the body with an approximate half-life of 2 hours. Most of the drug is excreted unchanged in the urine, the serum half-life after oral administration is 0.5-0.7 hours. Due to the chemical degradation, cefaclor does not accumulate to the same degree as other cephalosporins in case of renal impairment.