The clinical science of antimicrobial pharmacology has been extraordinarily useful in guiding treatment of patients with life-threatening bacterial infections. When the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the antibacterial agent used has been ≤1 μg/mL, and peak concentration of drug in serum has been 100 times greater, and further, when therapeutic concentrations of the administered agent could be maintained for considerable parts of the treatment days, salutary effects have been astounding! These simple conditions have been achieved for staphylococcal, pneumococcal, Haemophilus, and various streptococcal infections, regardless of whether the involved pathogen has had the capability of producing β-lactamases that inactivate penicillin G. Penicillins, cephalosporins, and chloramphenicol have been used. With the addition of an aminoglycoside along with penicillin G, enterococcal infections could also be eradicated.
Judicious use of penicillin G, ampicillin, and semisynthetic β-lactamase-resistant penicillins such as methicillin, nafcillin, oxacillin, or cloxacillin has decreased the mortality