Profound hemolytic anemia developed in three glucose 6-phosphate dehydrogenase (G6PD)-deficient males while they were receiving 25 mg of dapsone (diaphenylsulfone) daily as prophylaxis for falciparum malaria. This suggests that, in some susceptible individuals, the hemolytic threshold for dapsone is lower than the 50 mg daily previously reported. Either individual variation in the degree of erythrocyte G6PD deficiency or concurrent administration of other potentially hemolytic drugs or both may account for this fact.
Chernof D. Dapsone-Induced Hemolysis in G6PD Deficiency. JAMA. 1967;201(7):554-556. doi:10.1001/jama.1967.03130070074028