Antimicrobial spectrum, pharmacology and therapeutic use of antibiotics. Part 2: penicillins.

The mechanism of action, resistance, antibacterial spectrum, clinical pharmacology, adverse effects, and therapeutic and prophylactic use of penicillins are reviewed. The choice of a penicillin is discussed. The only indication for the penicillinase-resistant penicillins is the suspected or demonstrated presence of Staphylococcus aureus. There are no important differences in therapeutic effect among oxacillin, cloxacillin, dicloxacillin or flucloxacillin by the oral route, or among oxacillin, dicloxacillin, nafcillin or methicillin parenterally. Ampicillin is especially useful for infections due to Haemophilus influenzae and Escherchia coli and for serious disease due to enterococcus and Listeria monocytogenes. Carbenicillin and ticarcillin exhibit unique activity against gram-negative bacilli (except Klebsiella).