The most important considerations when prescribing penicillins are the likely susceptibility of the pathogen and the risk of serious hypersensitivity reactions.
Benzylpenicillin (penicillin G) and phenoxymethylpenicillin (penicillin V) retain activity against streptococci, and represent effective therapies with low acquisition costs. Similarly, benzylpenicillin remains the preferred empirical therapy for adult bacterial meningitis and is generally suitable for pneumococcal infections.
Amoxicillin is recommended for the prophylaxis of postoperative streptococcal endocarditis. In other indications, for example empirical therapy of respiratory tract infections, newer agents such as macrolides, fluoroquinolones and/or cephalosporins are now preferred.