Abstract
Is the patient receiving the proper drugs? Is he being given sufficient amounts to eradicate the infection? Every physician asks himself these questions when faced with the antimicrobial treatment of a serious infection. In many well-defined bacterial infections, clinical experience alone can supply an adequate answer. However, with the changing behavior of microbes and the changing natural history of infectious processes, additional guidance is often welcome and sometimes essential for optimal therapy. It is the purpose of this communication to draw attention to a helpful laboratory test, the assay of antibacterial activity in serum of patients receiving antimicrobial drugs. The test is simple, inexpensive, can be learned by any laboratory in a short time and—if properly interpreted—can aid the physician in the management of severe infections. To be effective in systemic infections, orally or parenterally administered drugs must be absorbed and distributed, in active form, to tissues harboring microorganism. Blood