Navalexin

Cephalexin is a semisynthetic analogue of Cephalosporin C. It kills bacteria by interfering in the synthesis of the bacterial cell wall. Peptidoglycan is a heteropolymeric structure that provides the cell wall with mechanical stability. The final stage in the synthesis of peptidoglycan involves the completion of the cross-linking and the terminal glycine residue of the Pentaglycine Bridge is linked to the fourth residue of the pentapeptide (d-alanin). The transpeptidase enzyme that performs this step is inhibited by penicillins and cephalosporins. As a result the bacterial cell wall is weakened, the cell swells and then ruptures. Cephalexin is a first generation cephalosporin that is active by mouth.

Side effects include nausea, vomiting, diarrhoea and abdominal discomfort. Symptoms of pseudomembranous colitis may appear either during or after antibiotic treatment. Skin rash, angio oedema, rise in serum aminotransferases, eosinophilia, neutropenia have been reported very rarely. Superinfection with resistant micro organisms, particularly candida may follow the treatment.

Pregnancy Category B. Cefalexin may be used during pregnancy when it is considered essential. Cefalexin is found in the milk of nursing mothers, hence caution should be taken when it is administered to nursing mothers.

Cefalexin should be given with caution in patients with renal impairment. Under such condition, careful clinical observation should be made because safe dosage may be lower than the usually recommended. The urine of patients receiving Cefalexin may give a false positive reaction for glucose with copper reduction reagent. Positive results to Coombs’ test have been reported. Although there is no evidence of teratogenicity in animal tests, Cefalexin may be used during pregnancy when it is considered essential. Cefalexin is found in the milk of nursing mothers, hence caution should be taken when it is administered to nursing mothers.

First generation Cephalosporins

Should be stored in cool and dry place.