THE FORMATION OF METHEMOGLOBIN AND SULFHEMOGLOBIN DURING SULFANILAMIDE THERAPY

Abstract

The free sulfanilamide, methemoglobin and sulfhemoglobin concs. of 960 blood samples from 476 patients receiving sulfanilamide were studied 58% of the patients showed methemoglobin in quantities demonstrable by the hand spectroscope; 7.8% showed sulfhemoglobinemia. The average methemoglobin conc. was proportional to the sulfanilamide conc. and was somewhat higher in the younger age groups. After a single dose of sulfanilamide, the maximal methemoglobinemia occurred several hrs. after the blood sulfanilamide had reached its peak. Sulfhemoglobinemia did not vary with sulfanilamide conc. but was more frequent after longer courses of the drug. An active substance is apparently normally produced in the course of sulfanilamide metabolism and this causes the production of methemoglobin.