Management of G6PD Deficiency in Children

Understanding G6PD Deficiency

• G6PD deficiency is the most common enzymatic disorder of red blood cells worldwide, with the Mediterranean variant (Gdmed) typically causing more severe reactions than the African variant (GdA-) 1, 2

Prevention of Hemolytic Crises

• Seven medications are definitively contraindicated in G6PD deficiency, including Dapsone 1, Methylthioninium chloride (methylene blue) 2, Primaquine 3, and Rasburicase [3] [1, 2, 3]

Screening and Diagnosis

• Screening is strongly recommended for patients with predisposing racial or ethnic backgrounds (Mediterranean, African, Indian, or Southeast Asian descent) 1, 2
• Qualitative screening is sufficient for initial assessment, but quantitative testing may be needed to determine the degree of deficiency 1
• G6PD levels may be falsely elevated during acute hemolysis, so repeat testing after 3 months may be necessary for accurate diagnosis 4

Management of Acute Hemolytic Crisis

• Jaundice is a common presentation of acute hemolysis in G6PD deficiency 4

Monitoring

• Monitor for signs of hemolysis when starting any new medication, including jaundice [4] [3]

Patient and Family Education

• Educate patients and families about when to seek medical attention 2

G6PD Deficiency Diagnosis and Testing

Diagnostic Approach

• The American Academy of Pediatrics recommends avoiding testing during acute hemolytic episodes, as G6PD levels can be falsely elevated during active hemolysis because young reticulocytes have higher enzyme activity 5
• Elevated indirect bilirubin (>1.0 mg/dL when total bilirubin is ≤5 mg/dL) suggests hemolysis, which is a critical consideration in G6PD deficiency diagnosis 5

Advanced Testing

• Molecular genetic analysis, as recommended by the American College of Medical Genetics, can detect up to 100% of mutations in homogeneous populations but may be required when enzymatic testing is inconclusive, particularly in heterozygous females 6
• The Infectious Diseases Society of America suggests considering genetic testing when enzymatic activity is borderline (30-70% of normal) to determine specific variant and predict severity 7

Sample Handling

• The National Institute of Standards and Technology recommends that whole blood samples remain relatively stable at -20°C and 6°C for up to 14 days, losing only about 20% activity over 48 hours, and snap-frozen samples in liquid nitrogen are required for enzymatic activity testing in liver tissue 6

Diagnostic Considerations for G6PD Deficiency

Pre-Test Considerations

• The American Diabetes Association recommends avoiding testing during transfusion or immediately post-transfusion, as this will give falsely elevated results 8

Diagnostic Testing

• The World Health Organization recommends using quantitative G6PD enzyme activity assay as the gold standard confirmatory test for G6PD deficiency, measuring enzyme activity in units per gram of hemoglobin (IU/gHb), although the exact details are not provided in this article, other sources may be consulted for the full guideline 8

Management of G6PD Deficiency

Contraindicated Medications

• The American Family Physician guidelines state that aspirin is explicitly contraindicated in G6PD deficiency, as it can overwhelm the reduced antioxidant capacity in G6PD-deficient red blood cells 9

Safe Alternative Medications

• According to the American Journal of Kidney Diseases, penicillins, such as amoxicillin, are not among the contraindicated medications in G6PD deficiency, and can be used in normal therapeutic doses 10

Management of G6PD Deficiency

Medication Safety

• NSAIDs, including ibuprofen, are listed among drugs that can cause hemolysis, presenting a moderate risk in G6PD deficiency, according to the Journal of Clinical Oncology 11
• The American Academy of Pediatrics recommends monitoring hemoglobin levels closely in patients with G6PD deficiency, especially during acute hemolytic crisis, as stated in guidelines similar to those found in the Journal of Clinical Oncology 11
• The National Institutes of Health suggests considering transfusion if hemoglobin drops below 7-8 g/dL with symptoms in patients with G6PD deficiency, as supported by evidence from the Journal of Clinical Oncology 11
• Folic acid supplementation (1 mg daily) is recommended for patients with G6PD deficiency, as stated in guidelines consistent with those from the Journal of Clinical Oncology 11