Nitrofurantoin in Urinary Tract Infections

To the Editor:— In "Long-Acting Sulfonamides in Urinary Tract Infection" (198:975, 1966), Dr. Seneca states, "Nitrofurantoin cannot be used for longer than two weeks especially in Negro patients who may have an intrinsic erythrocyte abnormality." No doubt Dr. Seneca is referring to those patients who show a defect in glucose 6-phosphatase dehydrogenase, commonly known as G6PD. We avoid giving nitrofurantoin to this group of patients by screening them with a simple test to detect this enzyme defect. I have found nitrofurantoin can be used for many weeks without apparent ill effect on the hematologic or nervous systems. It has been shown by Dr. Stamey that tissue levels and urinary levels are adequate for antimicrobial therapy and that the blood level of nitrofurantoin, though low, does not bear a relationship to the clinical response in urinary tract infection.