Ampicillin sodium is a broad spectrum semi synthetic penicillin. This product has strong antibacterial effect on Streptococcus haemolyticus, Streptococcus pneumoniae and Staphylococcus aureus without penicillinase, which is similar to or slightly inferior to penicillin. Ampicillin also had a good antibacterial effect on Streptococcus viridis, and its effect on Enterococcus and Listeria was better than that of penicillin. The product has antibacterial activity against Corynebacterium diphtheriae, Bacillus anthracis, actinomycetes, Haemophilus influenzae, Botrytis pertussis, Neisseria and anaerobic bacteria except Bacteroides fragilis. Some Proteus mirabilis, Escherichia coli, Salmonella and Shigella are sensitive to this product.
  Ampicillin has bactericidal effect by inhibiting the synthesis of bacterial cell wall.