Introduction
Semisynthetic, broad-spectrum antibiotic derivative of cephalexin.
Uses
Cefaclor is a second generation cephalosporin used to treat a wide variety of infections in the body.
For the treatment of certain infections caused by bacteria such as pneumonia and ear, lung, skin, throat, and urinary tract infections.
Associated Conditions
Pharmacodynamics
Cefaclor is a second generation cephalosporin antibiotic with a spectrum resembling first-generation cephalosporins. In vitro tests demonstrate that the bactericidal action of the cephalosporins results from inhibition of cell-wall synthesis. As indicated by in vitro and in vivo clinical studies, cefaclor was shown to be effective against most strains of Gram positive aerobes - Staphylococci (including coagulase-positive, coagulase-negative, and penicillinase-producing strains), Streptococcus pneumoniae, Streptococcus pyogenes (group A ß-hemolytic streptococci), as well as Gram-negative aerobes - Escherichia coli, Haemophilus influenzae (including ß-lactamase-producing ampicillin-resistant strains), Klebsiella sp, and Proteus mirabilis.
Mechanism of Action
Cefaclor, like the penicillins, is a beta-lactam antibiotic. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, it inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins. It is possible that cefaclor interferes with an autolysin inhibitor.
Absorption
Well absorbed after oral administration, independent of food intake.
Protein Binding
23.5%
Route of Elimination
Approximately 60% to 85% of the drug is excreted unchanged in the urine within 8 hours, the greater portion being excreted within the first 2 hours.
Half Life
0.6-0.9 hour
Toxicity
Symptoms of overdose include diarrhea, nausea, stomach upset, and vomiting.
Food Interactions
- Take with or without food.
Dosage
Powder for suspension & Pediatric drops: Children: The usual daily dosage for paediatric patients over 1 month is 20 mg/kg/day in divided doses every 8 hours. In serious infections such as otitis media and infections caused by less susceptible organisms, 40 mg/kg/day are recommended, with a maximum dosage of 1 g/day. Safety and effectiveness of Cefaclor for use in infants less than 1 month of age have not been established.
<1 year (9 kg):
- Powder for suspension: ½ tsp three times daily
- Pediatric drops: 0.625 ml three times daily
- Powder for suspension: 1 tsp three times daily
- Pediatric drops: 1.25 ml three times daily
- Powder for suspension: 2 tsp three times daily
In patients undergoing haemodialysis: Haemodialysis shortens serum half-life by 25-30%. In patients undergoing haemodialysis, a predialysis loading dose of 250 mg-1 g is recommended. A maintaining dose of 250-500 mg every 6 hourly during interdialytic period may be used.
Geriatric use: Clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
