Amoxicillin (International Nonproprietary Name), or amoxycillin (British Approved Name), is a moderate-spectrum, bacteriolytic, -lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms. It is a broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration (PubChem). Amoxicillin is active against a wide range of Gram-positive and a limited range of Gram-negative organisms. It is susceptible to degradation by beta-lactamase-producing bacteria, and so may be given with clavulanic acid to increase its susceptibility. The incidence of beta-lactamase-producing resistant organisms, including E. coli, appears to be increasing. Amoxicillin binds to penicillin-binding protein 1A (PBP-1A) located inside the bacterial cell wall. Penicillins acylate the penicillin-sensitive transpeptidase C-terminal domain by opening the lactam ring. This inactivation of the enzyme prevents the formation of a cross-link of two linear peptidoglycan strands, inhibiting the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that amoxicillin interferes with an autolysin inhibitor. Amoxicillin is usually the drug of choice within the class because it is better absorbed, following oral administration, than other -lactam antibiotics. Amoxicillin in trihydrate form is available as capsules, chewable and dispersible tablets, syrup and pediatric suspension for oral use, and as the sodium salt for intravenous administration. It is one of the most common antibiotics prescribed for children, and the liquid forms are helpful in cases where the patient might find it difficult to take tablets or capsules. It has three ionizable groups. Amoxicillin as a once-daily dosing form (Moxatag) was approved by the American FDA in January 2008. Amoxicillin is one of the semi-synthetic penicillins discovered by Beecham scientists. The patent for amoxicillin has expired, thus amoxicillin is marketed under many trade names, including Actimoxi, Alphamox, AMK, Amoksibos, Amoxiclav Sandoz, Amoxidal, Amoxil, Amoxin, Amoksiklav, Amoxibiotic, Amoxicilina, Apo-Amoxi, Augmentin, Bactox, Betalaktam, Cilamox, Curam, Dedoxil, Dispermox, Duomox, E-Mox (250mg and 500 mg), Enhancin, Gimalxina, Geramox, Hiconcil, Isimoxin, Klavox, Lamoxy, Moxatag, Moxilen, Moxypen, Moxyvit, Nobactam, Novamoxin, Ospamox, Panklav, Pamoxicillin, Panamox, Polymox, Samthongcillin, Clamoxyl, Senox, Sinacilin, Trimox, Tolodina, Wymox, Yucla, Zerrsox, and Zimox. Amoxicillin is found in milk and milk products. It is a potential contaminant in cow's milk arising from its veterinary use.