Glucose-6-phosphate dehydrogenase deficiency is an inherited enzyme deficiency that affects around 400 million people worldwide. It is more common in people of Mediterranean, African, or Asian descent. This gene has persisted in those regions due to the fact that it provides some protection against malaria. In the United States it affects about 10% of African American males. Babies with this condition may have jaundice at birth.
Patients with this enzyme deficiency have less protection against oxidative stress, due to decreased amounts of NADPH (nicotinamide adenine dinucleotide phosphate) which protects red blood cells. The degree of the deficiency determines the clinical symptoms. Patients with a minor deficiency may not have any symptoms.
Most people who have this condition do not require treatment but they will need to avoid certain foods and drugs or they may develop hemolysis, a breakdown of red blood cells which leads to anemia.
Pharmacists and other health care providers should be aware of medications that should be avoided by patients with G6PD deficiency. These include dapsone, sulfa drugs, nitrofurantoin, flutamide, methylene blue, phenazopyridine, chloroquine, and NSAIDs.
People should also avoid exposure to moth balls containing naphthalene.
Patients should avoid eating fava beans, also known as broad beans or pigeon beans. Sensitivity to fava beans is more common in G6PD patients of Mediterranean descent.
If anemia does develop, it is typically self-limiting and resolves in 1-2 weeks. More severe cases may require a blood transfusion.
Symptoms of hemolysis include paleness, dark urine, fatigue, enlarged spleen, and rapid heart rate. A blood test can be used to diagnose G6PD deficiency.