DRUG REACTIONS, ENZYMES, AND BIOCHEMICAL GENETICS

TLDR

Drug idiosyncrasy involves distinguishing immunologic drug allergy from hypersusceptibility or hyposusceptibility reactions, which were poorly understood until recent advances. Recent data show that primaquine‑induced hemolytic anemia is linked to genetic traits or enzyme deficiencies, affecting about 10 % of African Americans and few Caucasians, and susceptible red blood cells exhibit reduced sulfhydryl groups.

Abstract

In discussions of drug idiosyncrasy, careful distinction should be made between toxic reactions caused by immunologic mechanisms (drug allergy) and abnormal reaction caused by exaggeration or diminution of the usual effect of a given dose. 1 Although some progress has been made in the study of mechanisms of drug allergy, little was known until recently about the pathogenesis of hypersusceptibility reactions and hyposusceptibility reactions. Data are available now which suggest that reactions of this type may be caused by otherwise innocuous genetic traits or enzyme deficiencies. Hockwald and his co-workers 2 demonstrated that approximately 10% of American Negroes and a very small number of caucasians developed hemolytic anemia when given an average dose of primaquine or chemically related drugs. Beutler and associates 3 showed that red blood cells of susceptible individuals possessed decreased numbers of nonprotein, sulfhydryl groups. It has now been pointed out that primaquine sensitivity is related to