THE CHEMOTHERAPEUTIC ACTIVITIES OF SULFAMERAZINE AND SULFAMETHAZINE

¹ From the Institute for Medical Research, Christ Hospital, Cincinnati, Ohio

The comparative activities of sulfamerazine, sulfamethazine, and sulfadiazine against experimental infections with pneumococci, hemolytic streptococci, Friedlander's bacilli, staphylococci and dysentery bacilli have been determined. The results have shown that sulfamerazine and sulfamethazine are slightly superior to sulfadiazine in the treatment of pneumococcal septicemia in mice and meningitis in rats. Sulfadiazine was as effective as or slightly more effective than the other drugs against infections with hemolytic streptococci and Friedlander's bacilli and was distinctly superior against infections with staphylococci and dysentery bacilli. The bearing of these observations on the clinical use of the 3 drugs has been discussed.

In vitro experiments have also been carried out to determine the capacities of sulfamerazine, sulfamethazine and sulfadiazine to inhibit the growth of pneumococci, Friedlander's bacilli, staphylococci, dysentery bacilli and E. coli. As was noted previously, the relative activities of the drugs depended upon the test medium. In the complex medium, sulfamerazine and sulfamethazine were somewhat more active than sulfadiazine against pneumococci, whereas sulfamethazine was the most active drug against staphylococci; the 3 drugs had essentially the same activity against the other organisms. In the synthetic medium, sulfamerazine and sulfadiazine were equally active against Friedlander's bacilli, E. coli and dysentery bacilli and were considerably more active than sulfamethazine. These results did not agree with the in vivo findings. An explanation for the discrepancy has been attempted.