Amoxicillin is a semi-synthetic, acid-resistant penicillin antibiotic with bactericidal activity. It acts by inhibiting bacterial cell wall synthesis and it is active against numerous Gram-negative and Gram-positive microorganisms. Amoxicillin has an excellent oral bioavailability and its absorption is unaffected by feeding. It is widely distributed in body tissues and fluids and shows a high tropism for the respiratory apparatus. Amoxicillin is non-toxic and is eliminated in active form through the urinary tract. Colistin is a polypeptide antibiotic active against Gram-negative microorganisms such as E. coli, Salmonella spp., Enterobacter aerogenes, Haemophilus spp., Pseudomonas spp., Shigella spp., and Bordetella spp. It attacks the cell membrane by lytic action, provoking leakage of intracellular contents and bacterial death. In addition to this bactericidal effect, colistin can neutralize lipopolysaccharides and prevent the pathophysiologic effects of endotoxins. The sulphate salt of colistin is stable in acid environment; it is not absorbed after administration by oral route and exercises maximum antibacterial activity in the gastroenteric tract. The amoxicillin-colistin association has a strong synergic effect and, also when administered orally, in virtue of the different pharmacokinetics of the two antibiotics, it allows efficacious therapy to be effected both in the gastroenteric tract and in the respiratory, urinary and tegumental apparata. INDICATIONS Infections of sensitive Gram-positive and Gram-negative microorganisms present in the following apparata: gastrointestinal, respiratory (bronchial and lung infections), urinary and cutaneous.