Cefalexin is a semi synthetic cephalosporin antibiotic for oral administration. Cefalexin is indicated in the treatment of the following infections due to susceptible micro-organisms: Respiratory tract infections Otitis media Skin and soft tissue infections Bone and joint infections Genito-urinary infections, including acute prostatitis Dental infections. Cefalexin is active against the following organisms in vitro: β-haemolytic streptococci; staphylococci, including coagulase-positive, coagulase-negative and penicillinase-producing strains; Streptococcus pneumoniae; Escherichia coli; Proteus mirabilis; Klebsiella species, Haemophilus influenzae; Branhamella catarrhalis. Most strains of enterococci (Streptococcus faecalis) and a few strains of staphylococci are resistant to cefalexin. Cefalexin is inactive against most strains of enterobacter, morganella morganii, pr. Vulgaris, Colstridium difficule, and the following species: legionella, campylobacter , pseudomonas or herellea species. When tested by in vitro methods, staphylococci exhibit cross-resistance between cefalexin and methicillin-type antibiotics.