Mechanism of Action
As with other cephalosporins, the bactericidal action of cefaclor results from inhibition of cell-wall synthesis.
Mechanism of Resistance
Resistance to cefaclor is primarily through hydrolysis of beta-lactamases, alteration of penicillin binding proteins (PBPs) and decreased permeability. Pseudomonas spp., Acinetobacter calcoaceticus and most strains of Enterococi (Enterococcus faecalis, group D streptococci), Enterobacter spp., indole-positive Proteus, Morganella morganii (formerly Proteus morganii), Providencia rettgeri (formerly Proteus rettgeri) and Serratia spp. are resistant to cefaclor. Cefaclor is inactive against methicillin-resistant staphylococci, β lactamase-negative, ampicillin-resistant strains of H. influenzae should be considered resistant to cefaclor despite apparent in vitro susceptibility to this agent.
Drug Label Information | Brands:
Brands of Cefaclor in Kenya
Ceclor®, Eli Lilly
Labclor®, Laboratory & Allied
Vercef®, Sun Pharmaceutical Industries Limited
Cefaclor is indicated in the treatment of the following infections when caused by susceptible strains of the designated microorganisms:
Otitis media caused by Streptococcus pneumoniae, Haemophilus influenzae, staphylococci, and Streptococcus pyogenes
Lower respiratory tract infections, including pneumonia caused by Streptococcus pneumoniae, Haemophilus influenzae, and Streptococcus pyogenes
Pharyngitis and Tonsillitis, caused by Streptococcus pyogenes
Note: Penicillin is the usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Cefaclor is generally effective in the eradication of streptococci from the nasopharynx; however, substantial data establishing the efficacy of cefaclor in the subsequent prevention of rheumatic fever are not available at present.
Urinary tract infections, including pyelonephritis and cystitis, caused by Escherichia coli, Proteus mirabilis, Klebsiella spp., and coagulase-negative staphylococci
Skin and skin structure infections caused by Staphylococcus aureus and Streptococcus pyogenes
DOSAGE AND ADMINISTRATION
Cefaclor is administered orally.
Adults–The usual adult dosage is 250 mg every 8 hours. For more severe infections (such as pneumonia) or those caused by less susceptible organisms, doses may be doubled.
Pediatric patients–The usual recommended daily dosage for children is 20 mg/kg/day in divided doses every 8 hours. In more serious infections, otitis media, and infections caused by less susceptible organisms, 40 mg/kg/day are recommended, with a maximum dosage of 1 g/day.
Cefaclor is contraindicated in patients with known allergy to the cephalosporin group of antibiotics.
Hypersensitivity reactions have been reported in about 1.5% of patients and include morbilliform eruptions (1 in 100). Pruritus, urticaria, and positive Coombs’ tests each occur in less than 1 in 200 patients.
Gastrointestinal symptoms occur in about 2.5% of patients and include diarrhea (1 in 70).
Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment
CNS–Rarely, reversible hyperactivity, agitation, nervousness, insomnia, confusion, hypertonia, dizziness, hallucinations, and somnolence have been reported.
Hepatic–Slight elevations of AST, ALT, or alkaline phosphatase values (1 in 40).
Hematopoietic–As has also been reported with other β-lactam antibiotics, transient lymphocytosis, leukopenia, and, rarely, hemolytic anemia, aplastic anemia, agranulocytosis, and reversible neutropenia of possible clinical significance.
There have been rare reports of increased prothrombin time with or without clinical bleeding in patients receiving cefaclor and warfarin concomitantly.
Renal–Slight elevations in BUN or serum creatinine (less than 1 in 500) or abnormal urinalysis (less than 1 in 200).