ROSH Gastrointestinal Practice Exam

Which antibiotic is known to precipitate hemolysis in a patient with G6PD deficiency?

1. Amoxicillin/Clavulanate

2. Cephalexin

3. Nitrofurantoin

4. Streptomycin

The correct answer is: Nitrofurantoin

In patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, certain drugs can induce hemolysis due to their oxidative stress effects. Nitrofurantoin is known to cause hemolytic anemia in these individuals because it generates reactive metabolites that can lead to oxidative damage of red blood cells. The underlying mechanism involves the inability of red blood cells in G6PD-deficient patients to properly manage oxidative stress, as their reduced ability to regenerate reduced glutathione leads to increased vulnerability to hemolysis when exposed to oxidants. Other antibiotics listed do not carry the same risk of precipitating hemolysis in G6PD deficiency to the same extent as nitrofurantoin. For instance, amoxicillin/clavulanate and cephalexin are generally considered safe for such patients, while streptomycin's association with hemolytic events is much less established compared to nitrofurantoin, making nitrofurantoin the most critical antibiotic to avoid in this context.