PRONTOSIL

(trade name), also called sulfamidochrysoidine, first of a long series of sulfa drugs. It was introduced into medicine in the 1930s for the treatment of bacterial infections. The introduction of Prontosil, a trade-name drug, marked a turning point in chemotherapy because it was the first synthetic drug found to cure general bacterial infections in man. Prontosil resulted from research, directed by the German chemist and pathologist Gerhard Domagk, on the antibacterial action of azo dyes. A red azo dye of low toxicity, Prontosil was shown by Domagk to prevent death in mice infected with streptococci. This dye was also effective in controlling staphylococcic infections in rabbits, but it was ineffective against pneumococcic and other experimental infections. These studies by Domagk excited interest in chemotherapy in France, England, and the United States. Within a relatively short period of time, it was demonstrated that Prontosil was effective in combatting experimental infections not only in animals but also against streptococcic diseases in man, including meningitis and puerperal sepsis. Later, it was found that the Prontosil molecule is disrupted in the tissues to form para-aminobenzenesulfonamide (designated sulfanilamide). Like other sulfa drugs, Prontosil was administered orally. It has been replaced in clinical use by newer sulfa drugs, including sulfanilamide, sulfathiazole, and others.