[Further aspects of combination antibiotic therapy. Critical review and personal case studies]

A brief account of the aims sought by multiple antibiotic management is followed by an assessment of the antagonism and synergism displayed by associations of two bactericidal antibiotics, two bacteriostatic antibiotics, and one bactericidal and one bacteriostatic antibiotic. Instances of synergism between bactericides (particularly penicillins and aminosides) are mentioned. Stress is laid on recent studies on the mechanism of action of antibacterial drugs showing unmistakeable synergism between trimethoprim and sulphamethoxazol and between chloramphenicol and tetracycline. The antagonism between bactericides and bacteriostatics noted by Jawetz et Al. has not been confirmed clinically in a number of reported series. The main indications for combined antiobiotic therapy are reviewed: endocarditis, purulent meningitis, staphylococcia, brucellosis, salmonellosis, shigellosis, other Gram-negative infections and fever in the course of blood diseases. References is made to personal experience in the management of 35 cases of bacterial endocarditis, 15 cases of purulent meningitis and various forms of serious Gram-negative infection. Leaving aside exceptional cases, the clinical effects of antibiotic associations are uncertain and influenced by too many variables. The technique is still of importance, however, despite the introduction of many new antibiotics. It must not be thought of as a handy method for indiscriminate use, however; its indications (which are summarised) are quite clear.