What is the treatment for G6PD (Glucose-6-Phosphate Dehydrogenase) deficiency?

Treatment for G6PD Deficiency

The primary treatment for G6PD deficiency is prevention of hemolytic episodes by avoiding oxidative stressors, including certain medications, fava beans, and infections, while using ascorbic acid (Vitamin C) at doses of 0.2-1.0 g/day when methemoglobinemia occurs. 1

Medication Management

Medications to Strictly Avoid

• Primaquine is contraindicated as it can cause severe hemolytic anemia in G6PD-deficient patients 1, 2
• Rasburicase is contraindicated due to its potential to cause severe hemolytic anemia 2
• Methylene blue (methylthioninium chloride) is contraindicated as it can worsen G6PD deficiency-related hemolysis 1, 2
• Dapsone is associated with significant hemolytic reactions and should be avoided 1, 3

Medications to Use with Caution

• Local anesthetics (benzocaine, prilocaine, lidocaine, tetracaine) should be used with caution as they may precipitate methemoglobinemia 1
• Sulfonamides, including sulfamethoxazole/cotrimoxazole, may pose a risk though recent data suggests they may be safer than previously thought 1

Clinical Management Approach

Screening and Prevention

• Qualitative screening for G6PD deficiency is recommended before starting therapy with any oxidant drug in patients with predisposing racial or ethnic backgrounds (Mediterranean, African, Indian, or Southeast Asian descent) 1, 2
• The most effective management strategy is prevention of hemolysis by avoiding oxidative stressors 4

Monitoring and Treatment

• Monitor for signs of hemolysis including jaundice, dark urine, fatigue, and pallor, especially when starting any new medication 2
• Ascorbic acid (Vitamin C) is the treatment of choice for methemoglobinemia in G6PD-deficient patients when methylene blue is contraindicated 1
• Dosing of ascorbic acid ranges from 0.2-1.0 g/day orally in divided doses 1

Acute Hemolytic Crisis Management

• If an acute hemolytic crisis is identified, the patient should be admitted for close observation and care 4
• Prompt diagnosis and management of acute hemolytic anemia is essential 5
• In severe cases, blood transfusions may be required, though this is rare 4

Important Considerations

Genetic Variants and Risk Assessment

• The severity of G6PD deficiency varies by genetic variant, with the Mediterranean variant (B- or Gdmed) typically causing more severe reactions than the African variant (A- or GdA-) 1, 2, 5
• Over 200 G6PD mutations are known, with approximately half being polymorphic and common in various populations 5

Patient Education

• Patients should be informed about risks along with signs and symptoms of an acute hemolytic crisis 4
• Patients should receive education about avoiding fava beans, which can trigger hemolysis 5, 6
• Patients should be provided with a list of medications to avoid 7

Special Situations

• Neonatal jaundice is a common manifestation of G6PD deficiency that requires monitoring and may need treatment 6
• Infections can trigger hemolysis in G6PD-deficient patients and should be promptly treated 5, 6