With the discovery in 1935 that the red dye Prontosil’s antibacterial effects were attributed to its breakdown product, intense interest focused on sulfanilamide. Unlike Prontosil, it was cheaper, had fewer adverse effects, did not impart a red color to the skin and was not subject to patent restrictions. Sulfanilamide had a simple chemical structure that was highly amenable to being modified into other sulfa (or sulpha in British English) drugs that were less toxic and could treat a wider range of infectious diseases. Before the availability of penicillin in the first half of the 1940s, sulfas were the best antibacterial drugs available.
SAVING PRIVATE RYAN. Many of these drugs were lifesaving, but not always (see Federal Food, Drug, and Cosmetic Act). During World War I, more troops died from combat infections than from enemy bullets and explosives, so in 1941–42 each U.S. soldier’s First Aid Packet was equipped with two sulfa drugs to prevent infection from severe wounds. Crystalline sulfanilamide, contained in 5-gram packages, was sprinkled over open wounds—a practice that continued until mid-1944, when it was determined that the powders were more harmful than beneficial. The packet also contained eight sulfadiazine tablets, which were to be taken with water until surgery, if needed. In the film Saving Private Ryan (1998), sulfa powder is sprinkled into Medic Wade’s multiple abdominal wounds, but to no avail. Former British prime minister Winston Churchill was more fortunate than Medic Wade: Sulfapyridine tablets (M & B 693) effectively treated pneumonia he contracted during a visit to North Africa in December 1943.
With the exception of urinary-tract and respiratory-tract infections, sulfa drugs are now rarely used, having been replaced by penicillin and other antibiotics. The demise of the sulfa drugs was hastened by bacterial resistance, adverse effects on the urinary tract and blood, and hypersensitivity reactions, some of which can be life-threatening.
Sulfa chemicals have been modified to create medicines used for the treatment of leprosy (Dapsone), fluid accumulation (Diuril), and diabetes (Orinase).
SEE ALSO Penicillin (1928), Prontosil (1935), Dapsone (1937), Federal Food, Drug, and Cosmetic Act (1938), Orinase (1957), Diuril (1958).
On the use of a sulfa drug to treat his pneumonia, Churchill said in a 1944 radio broadcast, “This admirable M & B [after M & B, the company that made it] . . . was used at the earliest moment and after a week’s fever the intruders were repulsed. I hope that all our battles will be equally well conducted.”