THE ACTION OF SULFAPYRIDINE (2-SULFANILYL AMINOPYRIDINE)

¹ From the Lilly Research Laboratories, Eli Lilly and Company, Indianapolis

1. Sulfapyridine appears to be more effective than sulfanilamide in mice against pneumococci, particularly types I, V, VI, VII, XVIII, XXIV, and XXIX, and staphylococcus aureus; equally effective against streptococci and meningococci; but less effective in typhoid infection. Either drug is able to save life, or to prolong life when it cannot completely protect it, from doses of cultures which would otherwise be fatal within 1 to 2 days.

2. Neither sulfapyridine nor sulfanilamide is efficacious in mice poisoned with rabic virus or influenza virus.

3. The true toxicity of sulfapyridine cannot be accurately estimated by mouth or by intraperitoneal injection in animals, because it is sparingly absorbed.

4. Dilute solutions of sulfapyridine when injected intravenously in anesthetized cats practically cause no changes upon respiration and circulation.

5. Compared with sulfanilamide, sulfapyridine is more difficultly absorbed as shown by the low blood concentration in rabbits and dogs.

6. Sulfapyridine is eliminated in urine in rabbits, dogs, and men. The total amount excreted in the urine of dogs varied from 5 to 15 per cent during 48 hours. Following ingestion of 2 grams, human subjects may excrete in urine from 60 to 91 per cent of the drug in 72 to 75 hours.

7. Sulfapyridine is also excreted feces, bile, pancreatic juice, and submaxillary secretion in dogs. It passes from maternal to fetal blood in pregnant rabbits.

8. Owing to its difficult absorption, daily administration of large doses of sulfapyridine to dogs per os do not produce significant changes in body weight, erythrocytes, leucocytes, hemoglobin, blood pH, and plasma CO₂ content, or pathological lesions which can be attributed to the drug.