[Aminopenicillin: when, how, what kind?].

The antibacterial activity of aminopenicillins is similar and includes penicillin-sensitive microorganisms and certain gram-negative species, particularly E. coli, P. mirabilis, Salmonellae, Shigellae and H. influenzae. Since penicillin G is less expensive, often more active and less likely to produce skin rashes than aminopenicillins, there is no reason to substitute aminopenicillins, there is no reason to substitute aminopenicillins for penicillin in situations where the latter would suffice. Of the various oral drugs of this class, amoxycillin and the esters of ampicillin (bacampicillin, pivampicillin) are better absorbed than ampicillin and epicillin and are thus effective at lower dosages. Amoxycillin has the advantage of having undergone extensive clinical investigation. For parenteral treatment amoxycillin and epicillin do not offer therapeutic advantages over ampicillin, which remains the best documented drug.