From the Guidelines
Patients with Glucose-6-phosphate dehydrogenase (G6PD) deficiency should avoid specific medications and foods that can trigger hemolytic crises, and screening for G6PD deficiency is recommended before starting therapy with an oxidant drug in patients with a predisposing racial or ethnic background. The management of G6PD deficiency involves avoiding triggers that can cause hemolytic crises, including antimalarials (primaquine, chloroquine), antibiotics (sulfonamides, nitrofurantoin, ciprofloxacin), analgesics (aspirin in high doses), and other drugs like rasburicase and methylene blue 1. Certain foods should also be avoided, particularly fava beans (which can cause favism), and patients should limit consumption of mothballs (naphthalene).
Key Recommendations
- Avoid specific medications known to trigger hemolysis
- Avoid certain foods that can trigger hemolytic crises
- Screening for G6PD deficiency is recommended before starting therapy with an oxidant drug in patients with a predisposing racial or ethnic background 1
- Patients should carry medical identification indicating their G6PD deficiency status and maintain regular follow-up with healthcare providers
During acute hemolytic episodes, treatment includes discontinuing the triggering agent, providing supportive care with intravenous fluids to maintain hydration and renal function, and blood transfusions for severe anemia (typically when hemoglobin drops below 7-8 g/dL) 1. Folate supplementation (1 mg daily) may be beneficial during hemolytic episodes to support red blood cell production. The condition requires lifelong management because G6PD deficiency is genetic and cannot be cured. The underlying mechanism involves reduced ability of red blood cells to protect against oxidative stress, as G6PD is essential for generating NADPH, which maintains glutathione in its reduced form to neutralize free radicals and prevent hemolysis.
Additional Considerations
- Qualitative screening for G6PD deficiency is recommended upon entry into care or before starting therapy with an oxidant drug in patients with a predisposing racial or ethnic background 1
- The use of primaquine or tafenoquine to prevent relapse in patients with P. vivax and P. ovale malaria requires testing for G6PD deficiency before treatment 1
From the FDA Drug Label
CONTRAINDICATIONS Severe glucose-6-phosphate dehydrogenase (G6PD) deficiency
- Treatment Recommendation: Primaquine is contraindicated in patients with severe G6PD deficiency.
- Key Consideration: Patients with G6PD deficiency should not be treated with primaquine due to the risk of hemolytic reactions. 2
From the Research
Treatment Recommendations for G6PD Deficiency
The treatment recommendations for patients with Glucose-6-phosphate dehydrogenase (G6PD) deficiency are primarily focused on avoiding medications that can trigger hemolysis. According to 3, medications can be divided into three groups:
- Medications that should be avoided in individuals with G6PD deficiency, such as dapsone, methylthioninium chloride (methylene blue), nitrofurantoin, phenazopyridine, primaquine, rasburicase, and tolonium chloride (toluidine blue)
- Medications that were considered unsafe by at least one source but can probably be given safely in normal therapeutic dosages to individuals with G6PD deficiency
- Medications where no evidence was found to contravene their use in G6PD-deficient patients
Medication Use and G6PD Deficiency
Studies have shown that primaquine and other drugs can trigger acute hemolytic anemia in subjects with G6PD deficiency 4, 5. It is essential to test a person's G6PD status before giving these drugs, especially in populations where G6PD deficiency is common. The use of primaquine and G6PD deficiency testing varies widely in malaria-endemic countries, with some countries adopting a single low dose of primaquine and others using a higher dose or not using primaquine at all 6.
Diagnosis and Management of G6PD Deficiency
G6PD deficiency can be diagnosed through detection of enzymatic activity or molecular analysis to detect known mutations of the gene encoding G6PD 7. Most individuals with G6PD deficiency are asymptomatic throughout life, but symptoms of acute hemolysis can include anemia, fatigue, back or abdominal pain, jaundice, and hemoglobinuria. The most common precipitators of oxidative stress and hemolysis in G6PD deficiency include medication use and infection.
Key Considerations
Some key considerations for patients with G6PD deficiency include:
- Avoiding medications that can trigger hemolysis, such as rasburicase, primaquine, dapsone, pegloticase, and methylene blue, until a G6PD diagnostic test has been performed 7
- Testing a person's G6PD status before giving certain drugs, especially in populations where G6PD deficiency is common 4, 6
- Being aware of the symptoms of acute hemolysis and seeking medical attention if they occur 7