Mixtures of antibiotics.

Abstract

The recent marketing of several novel mixtures of antibiotics has revived interest in the value of combinations of antibiotics. Various claims have been made for the superiority of a mixture of two antibiotics over either of the drugs used alone. It is claimed that mixtures of antibiotics should be used for the following reasons: (1) to produce a better therapeutic result than can be achieved by maximal dosage of either antibiotic alone (synergism), (2) to achieve a therapeutic result with nontoxic doses of two antibiotics that would require a toxic dose of either antibiotic alone, (3) to prevent or delay the appearance of resistant strains of infecting organisms, (4) to treat mixed infections in which no single antibiotic is effective against all of the organisms present, and (5) to treat seriously ill patients before a bacteriological diagnosis is made. These claims will be considered in the order in which they