The effect of 8 different drugs on the survival of primaquine-sensitive red cells transfused into normal volunteers. Primaquine, sulfanilamide, acetanilid, phenylhydrazine, sulfoxone, and phenacetin in the doses shown cause significant hemolysis of the primiquine-sensitive cells. Hydroxyacetanilid and para-aminobenzoic acid did not prove to be hemolytic. (Reprinted from Dern et al17 with permission from Elsevier.)