Amoxicillin is a broad spectrum bactericidal antibiotic belonging to the B lactamic group.
It is semisynthetic penicillin-susceptible to the action of penicillinases.
prevents bacterial cell wall synthesis by inhibiting of transpeptidase and carboxypeptidase enzymes, causing an osmotic imbalance that destroys bacteria during the growing phase.
active against:
Gram-positive bacteria: Actinomyces spp., Bacillus anthracis, Clostridium spp.,
Corynebacterium spp., Erysipelothrix rhusiopathiae, Listeria monocytogenes, Staphylococcus spp., Streptococcus spp.
Gram-negative bacteria: Actinobacillus spp., Bordetella bronchiseptica, Escherichia coli, Fusobacterium spp., Haemophilus spp., Moraxella spp., Pasteurella spp., Proteus mirabilis, Salmonella spp. In addition to Leptospira spp.
As often as they are non-penicillinase-producing strains. Most of Klebsiella and Enterobacter strains are resistant as well as almost all Pseudomonas.
Some microorganisms become resistant by producing B-lactamases, which break the B-
lactamic ring of amoxicillin, turning it inactive.
It is well and rapidly distributed in the organism, achieving high concentrations in muscle, liver, kidneys, and intestinal tract, due to its low binding to plasmatic proteins 17-20 %.
It diffuses poorly into the brain and spinal fluids except when the meninges are inflamed.
crosses the placental barrier.
The drug is sparingly metabolized; most of it is excreted in the urine and, to a lesser extent, in the milk and bile maintaining the entero-hepatic circulation.